Karl Dahlke karl@eklhad.net 248-524-1004 (during regular business hours)
As a special exception, I hereby grant permission to link the code of this program with the OpenSSL library (or with modified versions of OpenSSL that use the same license as OpenSSL), and distribute linked combinations including the two. You must obey the GNU General Public License in all respects for all of the code used other than OpenSSL. If you modify this program, you may extend this exception to your version of the program, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.
I would be dead in the water if it weren't for a cadres of excellent online tutorials. Their technical writing puts mine to shame. Please look through some of these web pages; you'll be glad you did.
Writing html
An html Code Tutorial
So You Want to Write some html...
Javascript for Webmasters
Javascript, the Definitive Guide
This package requires Spider Monkey Javascript, released by Mozilla under the MPL. You can download it here. Programmers and maintainers of this package should take advantage of the online documentation.
Reinventing ed seems like a complete waste of time, until you realize that this program also acts as a browser - a browser embedded inside ed. You can edit a URL as easily as a local file, and activate browse mode to render the html tags in a manner that is appropriate for a command-response program such as this. In other words, we discard most of the formatting information and retain the links and fill-out forms. This allows blind users to access the Internet via an application that is entirely compatible with the linear nature of speech or braille.
I find this approach superior to the "quick fix" of pasting an adaptor onto a preexisting screen browser (lynx) or graphical browser (Netscape). Of course that's just my opinion. To be fair, many blind users, even totally blind users, are satisfied with their auditory screen scrapers. I'm glad it works for them, but this approach frustrates the hell out of me. If you also prefer linear applications, give this browser a try.
This documentation assumes you are familiar with ed. In fact it helps if you are fluent in ed. Experience with internet browsers and the associated terminology is also helpful.
q: quit the current session qt: quit the program completely, whether you've written your files or not !command: shell escape p: print the current line 4,7p: print lines 4 through 7 'a,'bp: print a range of lines, marked with labels a and b kb: mark the current line as b l: list the current line, showing nonascii chars in hex n: print the current line with its line number =: print the number of lines in the file z22: print the next 22 lines s/x/y/: replace x with y on the current line s/x/y/2: replace the second instance of x with y on the current line 4,7s/x/y/g: replace all instances of x with y, on lines 4 through 7 /x/: look for the line containing x /x/i: look for the line containing x or X ci: searches and substitutions are case insensitive cs: searches and substitutions are case sensitive sg: substitution strings are global across sessions sl: substitution strings are local to their sessions lc: convert line to lower case mc: convert line to mixed case uc: convert line to upper case h: help, explain the last question mark f: print the name of the current file f foo: set the file name to foo f/: retain only the lass component of the filename e: print the number of the current session e3: move to session 3 e foo: edit the file named foo r foo: read the contents of foo into the current buffer w foo: write the current buffer to foo w+ foo: append to foo w/: write to the lass component of the filename d: delete the current line 1,$d: delete all the lines, 1 through eof u: undo the last command i: insert text before the current line, end with a period c: change the current line, enter a new block of text, end with period a: add text after the current line, end with a period a+: include the line you just typed in, when you thought you were in append mode 4,7m11: move lines 4 through 7 to line 11 4,7t11: copy lines 4 through 7 to line 11 3,4j: join lines 3 and 4 together 3,4J: join lines 3 and 4 together with a space between g/x/ p: print every line that has an x v/x/ p: print every line that does not have an x B: find the line with the balancing brace b: brouse the current file, which is assumed to be in html b foo.html: edit the file foo.html and browse it b url: fetch url from the internet and browse it ub: unbrowse a file g: go to the link on the current line g2: go to the second link on the current line ^: the back key, go back to the web page you were looking at before i=xyz: set the input field on the current line to xyz i2=xyz: set the second input field on the current line to xyz i2*: push the second button on the current line, usually submit or reset i3?: describe the third input field on the current line db: set debug level [0-7] cd: change directory bl: break line into sentences and phrases dr: directory is readonly dw: directory is writable, and d moves files to your recycle bin dx: directory is writable, and d deletes files hf: show hidden files in directory listing (toggle) bd: binary detection on files (toggle) eo: end markers off el: show end markers ^$ when a line is listed ep: show end markers when a line is listed or printed pb: play buffer ft: show the title of the current web page fd: show the description of the current web page fk: show the keywords of the current web page hr: http redirection (toggle) js: allow javascript (toggle) sr: send referrer (toggle) tn: send dos-style newlines on lines in textareas (toggle) fma: ftp mode active fmp: ftp mode passive fmd: ftp mode default, passive then active rf: refresh the web page or directory listing et: edit this web page as pure text vs: verify ssl connections (toggle) ip: show referenced ip numbers, usually for saved mail messages sm: send mail [account number]
If you just want to read the whole document, type ,p. That works, if you use a command line speech adapter. The whole document is in buffer, and you can read through it using the function keys on your adapter. Now I realize most people still use screen readers, so this won't work. Still, there's an easy way to step through screen by screen. Start with 1z20 to get the first 20 lines. Then the z command will give you the next 20, and the next 20, and so on. You may want to use 22, or 24, or whatever makes sense relative to your screen.
Another approach is to simply hit return, again and again, and proceed line by line. You may need to hit a function key to "read" each line, after you hit return, or maybe not, if your adapter has an autoread feature.
Once you are use to the regular expressions, you can jump to any part of the document, even a large document, in record time simply by searching for a unique text fragment. This comes with practice. Sometimes I guess wrong, and my search string is not unique. I wind up somewhere else and have to search again. This doesn't happen very often. I usually get to the right place in one or two tries.
If you want to mark certain lines of text, please don't try to remember the line numbers. Use the k command to mark them. I usually use ka and kb to mark the start and end of a block of text, while kc marks the new location. The move command is then 'a,'bm'c - with absolutely no line numbers. (This is standard ed fair, though most people never take advantage of it.)
To look for links on a web page, search for the right brace. Yes, you may stumble across a literal right brace in the text, but this doesn't happen very often. You might access a particular link by typing /{Next}/g. Similarly, you can look for input fields by searching for the greater than sign. (This will make sense as you read about the representation of web pages.) And of course, multiple operations can be scripted, a feature unique to this browser.
These are just some of the tips and tricks that will make you as fast and efficient as anybody using a screen editor or browser, provided you are familiar with the page. (You will never be faster than your sighted colleague when traveling through unfamiliar territory, no matter what system you use.) My wife is always amazed at how quickly I can negotiate websites, or edit the common documents that we work on together.
Great! You've read the perlre man page, and you're back. Here are a few changes that I've made to perl regular expressions. I have found that ( and ) are almost always meant to be literal, as in searching for myFunction(), so I reverse the sense of escaped parentheses in perl. That is, ( and ) now match the literal characters, and \( and \) are used to demark substrings of the matched text. These substrings are then referenced, in the replacement string, by $1 through $9. Similarly, | means a literal |, and \| is alternation. I also change the sense of &, on the right hand side, to mean what it means in ed. I leave ^ $ . [ ] + * ? and {m,n} alone, to be interpreted by perl, as described in the perlre man page. However, if * is the first character, it is treated as a literal star. This makes sense, as there is no previous character to modify. Some versions of ed do this, some don't. But I find it convenient; when I want to replace * + or ?, I don't have to escape it, just because it is a modifier. Similarly, an open bracket by itself is treated as literal. These changes to regexp, to look more like ed, may be confusing if you are a perl expert. Sorry about that, but I think these changes make this editor much easier to use for everyone, especially the experienced ed users. Below are some additional differences between this program and /bin/ed.
Unlike bash, edbrowse does not retrace your steps back through symbolic links. Thus .. is always the physical parent directory.
environment variables are expanded before the cd command is applied, including the leading ~. Thuse cd ~/work takes you to the work directory under your home directory.
This command does not change any filenames that may be active. You can edit foo, cd .., and write, and foo will be copied to the parent directory. That's probably not what you want, so be careful.
Shell metta characters are also expanded, provided the result is one file name. You can read or write a file by typing a minimal portion of its name. Neither $variables nor stars are expanded for files on the command line, as this expansion is already done by the Unix shell. Windows users should compile using the setargv.obj utility, which performs wildcard expansion on command line arguments. Thus you should be able to edit *.c in any operating system and get all the C source files in the current directory.
However, I realize most people still use screen readers, where trailing whitespace is indistinguishable from the blank screen, and a wrapped fragment is sometimes mistaken for a second line. Therefore, you can use the command `el' to place end markers around listed lines. Listed lines begin with ^ and end with $. Enter `ep' to place end markers around all printed lines. Use `eo' to turn end markers off.
Subsequent sections describe new and interesting features, completely foreign to ed. These include the simultaneous edit of multiple files similar to emacs and vi, and the ability to browse an html file and "edit" its fill-out form. That's why I wrote the program in the first place.
if(x == 3 &&
y == 7) {
printf("hello\n");
} else {
printf("world\n");
exit(1);
}
The capital B command, on either the second or the last line, moves to the middle line "} else {", because that balances the open brace. On the first line, B moves to the second line, which balances the open parenthesis. The second line balances {, rather than ), because braces have precedence over parentheses, which have precedence over brackets. You can force a parenthesis match by typing B), which moves from line 2 back to line 1.
The B command on the else line is ambiguous - I don't know whether to look backwards or forwards. You must type B{ or B}.
You can explicitly balance <>, as in multiline html tags, or `', used in some preprocessors such as m4.
Comments or literal strings that contain balancing punctuation marks will definitely throw edbrowse off the track. If you are the author of the source, you might want to avoid braces in comments, or use comments to keep braces in balance.
static char openstring[] = "{block"; /* closing } is found elsewhere */
If you quit a session you are moved to the next valid editing session, wrapping around to session 1 if necessary. The program exits when the last session quits.
Warning, the program contains a bug regarding the undo command. If you switch to another session, then switch back, you cannot undo your last edit. You'd think this would be easy to fix, but it is trickier than it seems, so I haven't gotten rround to it. I just wanted you to know. Make sure everything is copasetic before you switch to another session.
Let's run through a cut&paste example. You are editing file foo in session 1, and you realize that a paragraph from file bar would fit perfectly right here. Here is how it might look. Lines beginning with < are the user's input, and lines beginning with > form the program's responses. The # sign delimits my injected comments.
< e2 # switch to session 2 > new session # Unlike ed, the r command does not establish a file name, even if the # buffer is empty. # Thus "r bar" is safer than "e bar". # The text is not linked to the file bar, # and we cannot accidentally corrupt this file. # After all, we don't want to change bar, we just want to steal from it. < r bar > 28719 < /start/ > This is the start of the cool paragraph that you want to copy. < 1,-d # don't need the stuff before it < /end/ > This is the end of the cool paragraph that you want to copy. < +,$d # don't need the stuff after it < e1 > foo < r2 > 3279 # size of text read from session 2 < q2 # clean house, get rid of session 2 < w # write foo, with the new paragraph included > 62121
The following moves the data from one file to another.
< e2 > new session < e bar # this time I'm going to change bar > 28719 < /start/ > This is the start of the cool paragraph that you want to move. < ka # mark the paragraph < /end/ > This is the end of the cool paragraph that you want to copy. < kb < 'a,'bw3 > 3279 < 'a,'bd < w # write bar, withouth the cool paragraph > 25440 < q > no file # now in session 3 < e1 > foo # back to session 1 < r3 > 3279 < q3 # quit session 3 remotely, while still in session 1 < w # write foo, with the new paragraph included > 62121
An e command, by itself, tells you the current session, in case you've forgotten. This is similar to f, by itself, which tells you the current file.
The -dx option sets the debug level to x, where x is between 0 and 9. The default is -d1, which prints the sizes of files as they are written and read. Some people like -d2, which prints the URLs as you jump to new web pages or submit forms online. Unless you are debugging the program, you probably don't want to go any higher than -d3. On rare occasions you might want to set -d4, to see the http headers in and out. Remember, the debug level can be changed on the fly by using the dbx command (x between 0 and 9).
The -e option causes edbrowse to exit when it encounters an error. This is usually used by batch scripts. If there is a problem, you don't want to march on, executing the rest of the edbrowse commands.
Use -c to suppress processing of, and edit, the .ebrc configuration file. (This config file will be described later.) And why would you want to do this? Suppose you have made a change to this file, and thereby produced a syntax error, so that edbrowse cannot even get started. Now you can't use edbrowse to fix your config file. Of course you could rename the config file to something else, fix it, and put it back; but then you might discover another syntax error, and so on. Instead, use the -c option to edit the config file directly. It is automatically loaded into buffer 1. Note that -c must be the first option.
The arguments are the files to edit. Edbrowse reads these files into corresponding sessions, and starts you off in session 1. If there are no arguments, you start in session 1, but there is no text and no associated file.
If you like this program, and you want it to be your primary editor, you can set the following Unix alias.
alias e="/usr/local/bin/edbrowse"
If you do this, you can use `e filename', to edit a new file, whether you are inside edbrowse or at the shell prompt. Very convenient.
Hello~07 ~x is ~bd of y
And then listed, you will see the very same text, but there is a bell and a 1/2 character inside. The ~x is not encoded into anything, because x is not a hex digit. If you want to force a ~, even though there are hex digits following, use two tildes, ~~.
When you are entering a regular expression, you have the choice, hex or octal. This program converts ~xx, as a hex value, and the perl regexp machinery converts \nnn, as octal. Thus any of the following will undos a file. The first is translated via my software, the second and third by perl regexp.
,s/~0d$// ,s/\15$// ,s/\r$//
Embedded escape characters are always displayed in hex, whether the line is listed or not. Most terminals and terminal emulaters, including the Linux console and my speech adapter, interpret various escape sequences as control commands. Thus an errant escape sequence from a binary file could send your terminal or your speech adapter into an unexpected state, making recovery difficult. It seems prudent to render escapes as visible characters all the time. If you have no idea where that ~1b came from, it's probably a literal escape character.
Returns and nulls are also converted into hex all the time. Thus an embedded return will not make one line look like two lines. You will usually see this when importing a dos text file. Every line ends in ~0d. Issue one of the three commands shown above to undos the file.
When binary data is first read into the buffer, you will see the words "binary data". After that the buffer remains "binary", even if you delete all the data and read in ascii text. You must use the `e' command to get a fresh, ascii buffer.
For the most part it doesn't really matter if the data is considered binary or ascii. Either way you can display and edit the data, and write it to a file.
This program tries to "do the right thing" under DOS/Windows. That is, it converts crlf to and from newline if it believes the file is text; and it leaves binary data alone. These distinctions are not relevant on Unix/Linux.
Although this approach is satisfactory for English and most European languages, it fails miserably for Asian languages, which definitely look like binary data. You can disable binary detection by entering the `bd' command. If you speak an Asian language, you may want to put this command in your init script, so edbrowse comes up the way you want - treating your international files as text files.
If you speak an Asian language, and you are running Windows, and binary detection is disabled, don't use this program to manipulate binary files, as they will get corrupted! Better still, say goodbye to Windows and start using a real operating system.
Like `ls -F', a subdirectory is indicated by a trailing slash. This slash is not part of the filename. Similarly, named pipe is indicated by |, symbolic link by @, block special by *, character special by <, and socket by ^. If a regular file ends in one of these characters, it may confuse you, but it won't confuse this program. Edbrowse knows whether that trailing | is part of the filename or a pipe indicator. Since each file is represented by a single line of text, files with newlines embedded in their names cannot be accessed.
If you read a directory into a preexisting file it is just text. You can't visit any of the underlying files, because they are just words. You must edit a directory in its own session or read a directory into an empty session if you want to access the underlying files. Note that you can write the buffer to another editting session, and in that session the words are just words. This distinction is important as we start to edit the text.
By default, directories are readonly. If you try to delete a line, and hence the associated file, it will tell you that you are still in directory read mode. I'm trying to save you from yourself! Type dw to enable directory writes, and dr to make directories readonly again.
When directory writes are enabled, you can remove files using the d command. For instance, g/\.o$/d removes all the object files. Since these edits have implications outside the scope of this program, there is no undo capability. When you make a change it is made. With this in mind, I borrowed a good idea from Microsoft. (That's one.) The deleted file isn't actually deleted; it is moved to your recycle bin, located in $HOME/.recycle. So if you accidentally type ,d and remove all your files, you can recover them from your recycle bin. You may want to set up a cron job that removes all the files from your recycle bin once a week. This directory is created mode 700, so nobody else can look at your deleted files. If you create this directory yourself, please make it 700. After all, some of your files might be private.
Because this operation is a move, rather than a true delete, there are a few restrictions based on your operating system. If your OS can move directories, this program will be able to delete a subdirectory as easily as a file. The entire subtree is moved to your recycle bin. Make sure your cleanup cron job is capable of removing directory trees, not just files.
Depending on your OS, you may not be able to move files across file systems. From /disk2 to /disk1, or from the D drive to the C drive. In this case you might want to issue the dx command, which makes directories writable, like dw, but actually deletes the files. You'll need this if you're trying to free up space on the disk. Note that symbolic links are always deleted; there isn't much point in moving a link to the recycle bin.
"What's the point of all this?" you may ask. "What's wrong with the shell?"
Nothing, as long as the file names are small and familiar. But sometimes the file names are long and cumbersome, and it is nearly impossible to type those names into the shell, character for character, upper and lower case, with no mistakes. Meta characters such as the * can help, but only when the file you want has a name radically different from the other files in the directory. This isn't always the case. Suppose an application generates log files as follows.
ProgramFooBar.-04-04-1998.06:31:59.log ProgramFooBar.-04-11-1998.11:37:14.log ProgramFooBar.-04-18-1998.16:22:51.log
How do you delete the old ones and keep the most recent, or rename them to something more manageable? Stars are a bit risky; you can access multiple files without realizing it. And we're not even talking about those pesky files with spaces or invisible control characters in their names. Our sighted friend calls up his file manager and simply clicks on the file he wants to view or edit or remove. Sometimes I want/need that kind of power.
When the substitute command changes text, it renames the underlying file. This won't move the file on top of another existing file, so you can't lose any data this way. Again, I'm saving you from yourself.
The search and substitute commands ignore the trailing filetype characters. If you want to rename a directory from foo/ to foobar/, you can type s/$/bar/. The bar will be placed at the end of the word foo, because the trailing / isn't really there.
Now suppose you want to run an arbitrary program on some of these files. This could be a print utility,a compiler, whatever. Sometimes you can rename the files for your convenience, then work in the shell. But sometimes you don't own the files, and sometimes they must retain their original names. This happens when several html documents reference each other through hyperlinks, using their existing filenames. So you can't rename the files, yet you still want to run your program on one or two of them.
You can run any program on any file without retyping that filename via the shell escape. Use kx to assign the label x to the file you are interested in. (This is standard ed syntax.) Then run !program 'x to invoke your program on that file. This sounds involved, but it is merely macro substitution, implemented in a few lines of code. If 'x is present in a shell escape, and is not next to any letters or digits, we replace it with the text on the line labeled x. Thus if your filename contains spaces, you'd better run !program "'x", to make sure the entire file name is one argument to the running program.
The token '. is replaced with the text on the current line, and the token '_ is replaced with the current filename. If you try to write a file, and remember that you left it readonly, you can make it writable via !chmod +w '_, then write the text to the file.
You can expand multiple tokens in one shell command. Use kx and ky to mark two files that you want to compare, then run !diff 'x 'y.
This feature is not limited to directory scans. You may be editing a simple file, but you can still paste the contents of a line into your shell command. Off hand I don't know why you'd want to do this, but you can.
This is especially useful in a directory scan. The last thing a blind person wants to worry about is whether some of the letters in a file name are upper case. If directory write mode is enabled, type ,lc to convert all the file names to lower case. It's that simple.
If you want to upcase a particular word, type s/word/uc/. This converts the word to upper case. All the other substitution suffixes apply. To change foo, Foo, FOo, and FOO to FOO, everywhere, type ,s/\bfoo\b/uc/ig.
I use this feature in two different ways. If I am familiar with the document, (I probably wrote it), I may use the bl command on a line of text that seems rather long. I typed it in quickly, as an uninterrupted thought, and now I want to break it up. But I don't want to count punctuation marks and say, "I think we need a break after the third comma and the period following that and then at the next comma", issuing the s punctuation commands along the way. Oh I like the s commands well enough - they put you in complete contrl - but it's easier to type bl - and bl usually does the right thing. Also, bl compresses accidental double spaces, a typo that I will never hear if I simply read the line as a whole.
When the document comes in from the outside, usually from another word processor such as MS-Word, bl serves a completely different function. Paragraphs are often stored on a single physical line. Sometimes the entire document is on a single line, with return characters, \r, separating paragraphs. Wysiwyg word processors don't worry about separating sentences and phrases - that's what word wrap is for. Well - bl is our version of word wrap. It doesn't try to conform to any screen; it merely cuts the text into manageable chunks, each piece a separate semantic unit. When bl is issued, physical lines will contain sentences or phrases, as delimited by punctuation, or by the newline/return characters embedded in the original document.
If one of the original lines, delimited by newline or return, is long, i.e. more than 120 characters, it is assumed to be a self-contained paragraph, and a blank line is added before and after. Thus a disassembled paragraph containing 20 sentences does not simply flow into the next disassembled paragraph containing 18 more sentences. An empty line separates the two paragraphs. This is only applicable if bl is applied to a range of lines, or the entire document, as might occur when making an outside document readable.
Don't apply the bl command to a preformatted section, such as a table or ascii art. If you're not sure what to expect, i.e. you didn't write the file, scan through it first, and apply bl to the range of lines that actually represents text. Often this is the entire document (,bl). The following commands do a pretty good job of cleaning up a typical Microsoft Word document.
e whatever.doc or whatever.wps # change filename, so you don't accidently overwrite the microsoft document f _ ,s/[~80-~ff~00-~0c~0e-~1f]//g # strip out non ascii control/formatting codes g/^\s*$/d # these blank lines use to contain non ascii codes ,bl # break lines and paragraphs 1,20p # first couple lines are often garbage, but then the text begins.
Of course the program catdoc does a better job of converting word documents into text. This is often bundled with xls2cvs. These are must-have programs for people who want a command line environment.
This is a narrow window to be sure; the computer has to fail at precisely the wrong millisecond. To guard against this improbable calamity, some editors write your data to a temp file, remove the true file, and move the temp file over to the true file. This way your data cannot be lost. Either the new or the old file will survive.
Then links came on the scene, hard links, and then symbolic links. Authors of ed, and other editors, had to scramble. You can't remove a link, write to temp, and move the temp file over to the link. It isn't a link any more, it's a regular file, and your filesystem is not what it use to be. For one thing, the true file, pointed to by the (symbolic) link, has not been changed at all. This is not what you want! So people rewrote there editors to disable this feature if the named file is a link to some other file. They had to revert back to the old truncate and write paradigm, and hope that nothing bad happens in between. And you know what, it never does. The window is just too small.
With this in mind, edbrowse doesn't mess with temp files at all. I just don't bother. I truncate the file and write out the data, and I don't expect anything to go wrong during the critical millisecond.
Another race condition is more subtle. Suppose you are editing a file and your friend, or a system program, edits the same file. Your file has actually been changed out from under you, while you held it in memory. When you go to write your changes, they will clobber any changes made by your friend, or the system utility. Most text editors guard against this by watching the timestamp. When you first edit the file foo, an editor might remember the timestamp on foo. then, when you are ready to write your changes, it checks the timestamp, and if foo has been updated in the interim, it issues a warning message. "File has been updated by someone else - do you really want to write?"
This is a good feature, but edbrowse doesn't have it, simply because I haven't gotten round to writing it. I'm the only user on my PC, and you're probably the only user on your PC too, so this feature is not in high demand. Still, I should implement it some day.
Note that this is not browsing, we are simply retrieving text from another machine and editing it locally. The text need not be html, it could be (for instance) a plain ascii document. Many people, myself included, put various types of files, even executables, on their websites for retrieval. Of course you wouldn't want to edit a binary file, but you can still use this editor to retrieve the file and save it locally, thus implementing an http download.
While inside the editor, you can type `e URL' to leave the current buffer and retrieve text from a remote machine. Or you can type `r URL' to retrieve remote text and add it to the current buffer. There is no `w URL' command, because the http protocol does not allow you to "write" html source back to a remote machine.
As a convenience, any filename with two or more embedded dots and a standard suffix (such as .com or .net) is treated as a URL. You can usually omit the http:// prefix. Try invoking `e www.space.com', as an example. But again, you are looking at html source, which probably isn't what you want. Browsing will be discussed later.
Whenever you retrieve data from a URL, the editor, directed by the http protocol, might change the filename out from under you. This is because the resource has moved, and the original computer was kind enough to give you the new address. If debugging is set to 2 or higher, you might see a series of three or four different URLs as the editor is redirected across the internet. Finally it retrieves your document, and the current file name holds the correct (latest) URL. You might want to update your bookmark file accordingly. Then again, you might not. Sometimes the initial url is the "public" location of the web page, and subsequent redirections occur inside the company. In this case you'll want to retain the public url, which will always work, even if the company relocates its web server. Use youre best judgment.
When the browse conversion is executed, the system checks for common syntax errors, such as a numbered list that is never closed. If the file name is a URL, these syntax errors are not reported. After all, it's not your web page, and there's nothing you can do about it. However, if the web page is yours, as indicated by a local filename, the first syntax error is displayed, whence you can return to the html source and fix it. Type `ub' to undo the browse conversion. This takes you back to the raw html text under its original filename. Now you can coorect the error and try the `b' command again. For your convenience, the label 'e is set to the line containing the error. Repeat this process until `b' runs without errors.
If you try to quit, and the editor says "expecting `w'", remember that you should be back in raw html before you issue the write command. You could write the browsed text into file.browse, and that will satisfy the "write" criteria, but this isn't really what you want. You've corrected errors in the html source, and that's what you need to save, so remember to undo the browse reformatting before you write the file.
Note that you can issue the unbrowse command even if there were no errors. If, for instance, you are looking at a well-constructed page on some other website, and you'd like to read or save the raw html, just type ub. As an exercise, invoke `e www.space.com', and use the `b' and `ub' commands to switch between the raw html and the browsable text.
The browse reformatting is relatively simple, because a blind person doesn't want complexity. We don't care about fonts and italics etc, and if we do, the best way to obtain this information is by reading the raw html. So most tags are discarded, except those related to headers, paragraphs, and lists.
I don't indent subsections or list items. The visual effect is lost on us, and sometimes the extra spaces get in the way.
Because the physical line is, for us, the unit of thought, i.e. the atomic construct that is modified or moved or copied, lines are cut at approximately 80 characters, give or take a few, usually at a sentence or phrase boundary. Thus reading line by line often reveals a sequence of sentences, or at least self-contained phrases within a larger sentence. I consider this the optimal way to view or edit a document -- any document. If you read this manual raw, without doing the browse on the file, you'll see what I mean. Review the break line command above.
The layout of a preformatted section, <pre>, is honored, although sequences of blank lines are compressed down to one blank line, and whitespace at the end of lines is stripped. This preserves the structure of street addresses, and other preformatted blocks.
Tables are formatted like an ascii unload from a spreadsheet or sql database. Pipes separate the fields on each row. There is no whitespace around the pipes, and the fields of a given row probably won't line up with the fields below. It isn't pretty, but a blind user can't really trace down a column in any case, especially when using a line editor such as this. Better to write the table to a local file and use cut, sort, join, etc. Here is a sample table.
part number|quantity|price 2635|2|$34.80 1398|1|$67.50 8118|5|$125.00
Empty fields at the end of a row are dropped. These are almost always images -- sometimes an entire row of images -- sometimes an entire table of images. The blind user doesn't need to read the no-content pipes.
Note that the browsable text is readonly. After all, it's not the "source" -- why should you edit it? There are ways to enter and edit the input fields of an on-line form, but this will be discussed later. For now, you can think of the text as readonly. Issue a copy or insert or substitute command, and you'll get an error.
If you do want to edit the text, as pure text, enter the `et' command (edit as text). You will not be able to return to the html that produced this page. Nor can you follow a hyperlink or submit a fill-out form. The browsable text has become plain text, with no internet semantics.
The command `b file.html' is shorthand for `e file.html', followed by `b'. Remember that the ub command reverses the browse conversion, and reproduces the original html text, as though you had entered `e file.html' alone.
If a url is opened from the command line, as in `e www.google.com', it is automatically browsed. Type `ub' to revert back to the raw html.
A subscript, as indicated by html tags, is enclosed in brackets. Thus x<sub>n</sub> becomes x[n]. This transformation is not done if the subscript is a one or two digit number. Thus x subscript 1 is rendered x1, just like your professor would say it. This is not ambiguous, as you might first think; only programmers use x1 as a variable name, not mathematicians. If you see x1 in a formula, it means x subscript 1. Even 17a3b3 is not ambiguous; it is a translation of 17 times a[3] times b[3].
Superscripts are enclosed in parentheses, with a preceeding arrow. The parentheses are omited if the superscript is a number. Thus x cubed looks like x^3, while x to the n-1 power looks like x^(n-1).
There are, sad to say, three different ways to encode mathematical symbols in html. At present edbrowse only supports one of them, though it is the most common, and the most portable among all browsers. This is the unicode system, where the Greek letter theta is specified as θ. Explorer turns this expression into θ, one character on the screen, while edbrowse turns it into the word theta. We also put spaces around the word if its neighbors are also words. This is illustrated by the circumfrence of a circle, which is 2 times pi times r. These three tokens are usually squashed together, and there is no confusion in the sighted world, where pi is a separate Greek letter. But if pi is spelled out, and the tokens are left together, the result is 2pir. Now pir looks like a three letter word. To avoid this, edbrowse inserts spaces, giving 2 pi r.
These translations are designed to work with the pages of the Math Reference Project, an archive of advanced mathematics that atemps to be both sighted and blind friendly at the same time. This may be impossible, but I'm giving it a whirl.
Note that `ft' prints the title of the web page, whereas `f t' (with a space) renames the current file to "t", which is probably not what you want.
If a web page is updated every minute, e.g. with the latest stock prices for your favorite companies, you can type rf to fetch the latest copy of this web page. This assumes the intervening internet servers are not caching the web page and handing you the same out-of-date copy over and over again.
On your local machine, you can use this feature to read the latest version of a dynamic file, such as a log file. Or you can reread a directory, to incorporate any new files that have been placed in that directory. For example, you might use the shell escape to execute `cat x y >z', yet z will not appear in your directory scan until you type rf.
{Recent reports} suggest a connection between autism and intestinal bacteria.
Behind the scenes, "recent reports" is linked to www.pecanbread.com/BTVCautismchapter.html, but you don't see that unless you activate the link or view the raw html.
Of course the browsable text might also contain words inside braces, especially if the web page is technical in nature. Hence there is some ambiguity. However, I believe it is clear from context. {More information} is probably a link, whereas ${HOME}/.profile is probably not.
Some web pages present a series of icons that are actually links to other pages. That is, you click on an icon, rather than a phrase, to go somewhere else. These icons are suppose to be intuitive. Sometimes they are -- sometimes they're not. In any case, they aren't much use to the blind. Sometimes the web designer is kind enough to supply a text phrase that roughly describes the image. In this case the phrase is used as the link. It appears in braces, as though there were no image at all. If there is no alternate phrase, the filename of the hyperlink reference is used. This name can be surprisingly helpful, or it can be utterly useless, as in "index.html". If this name canot be determined, the generic link {image} is used. In this case you will have to go to the web page to find out what it contains.
To follow a link, enter the `g' (go) command. Yes, `g' also initiates a global command, such as a global substitute, but only when it is followed by a regular expression. By itself, g follows the link on the current line, g2 follows the second link on the current line, and 4g follows the link on line 4. If a link spreads across multiple lines, you must be on the first of these lines, the line containing the left brace.
The g command can also act on a link that is written in raw text, as long as it "looks" like a valid url. If your friend sends you an interesting url via email, and you save it to a text file, you can "go" to that link, even though the file is not html, and you've never issued a browse command.
The g command follows an internal link or an external link. Either way you find yourself in a different place. However, if the link is internal, you are still browsing the same file. In fact, the only thing that has changed is the current line number. The new line is displayed, and should correspond to the link you activated. Often the words are the same. Activate {Appendix I}, and you'll probably see the section heading "Appendix I". Enter z10 to read the first few lines of the appendix.
This feature seems rather silly if you're just editing files, but it makes sense when surfing the net. Often we descend through two or three links, only to find ourselves at a dead end. "I didn't want to go here." So we hit the back key again and again, until we reach familiar territory. We can now proceed in a new direction. The command ^3 or ^^^ backs up through three pages. Don't use this iterative feature unless you know exactly how many times you need to back up.
Note that the entire state of an editing session is saved and reproduced, including the file name, the last search/replace strings for substitutions, the hyperlinks and forms, the compiled javascript, everything!
Unlike lynx, I don't keep a running history of every web page visited. I never really saw a need for this feature. 99% of the time I simply want to back up one or two pages, and that's it. Unfortunately this high-runner operation requires two somersaults and a back flip under lynx. It is a one key command in my browser.
The stack should not be confused with parallel edits, as described in an earlier section. In fact each editing session, e1 e2 e3 ..., has its own internal stack. Parallel sessions are appropriate when you need to move back and forth between two files, or cut&paste between them. However, one session, with its internal stack, is usually sufficient to surf the net.
If a browse command fails completely, giving you a rather uninteresting empty buffer, the stack is popped automatically, taking you back to the previous web page. Now you can retry the link by typing `g' again, or follow a different link on the page. Note that a browse command can fail, and still give you text explaining why it failed, if the remote server is well-designed. In this case you may see the error message "file not found", yet you will be viewing a new web page, which explains the problem. After you've read the explanation, follow its directions, or type ^ to back up and try again.
If you are presented with a number, even 0, the stack has been pushed, and you are in a new file or url. The number is the size of the new file. Use the ^ command to get back. If there is no number, merely an error message, then edbrowse did not create a new buffer. It probably didn't get that far. Typing . will produce the same line you saw before.
Following an internal link to another section in the current document does not push anything onto the stack. In other words, ^ will not take you back to where you were. In fact, it will take you up to the previous web page, which is not what you want. If you want to take a glance at Appendix I, and then return, mark the current position with `kr'. After you've visited the appendix, use the label 'r to return to your original location in the file.
It is generally unsafe to make a copy of a running web page, with all its javascript objects etc, so the M command moves the page out of the way, and takes you back to the previous page. Note, this command works just as well with files.
Suppose a web page presents
{planes}
{trains}
{automobiles}
If you are curious about all three topics, issue these commands in this order.
1g M2 2g M3 3g M4
Now sessions 2 3 and 4 are the subpages about plains trains and automobiels respectively. You can fill out forms or follow hyperlinks in any of them, or stay in session 1 and do something else.
{Background Music}
This always appears at or near the top of the page. Click on this link and download the wave or mp3 file, and play it at your convenience. Use the play buffer `pb' command. Normally pb uses the name of the file to infer the audio format. If the filename ends in .wav, it's a wave file, and so on. If the filename is not particularly helpful, and you know the audio format, you can specify it by typing pb.wav for a wave file, pb.mp3 for an mp3 file, and so on.
The config file (described below) includes mime type descriptors, which tell edbrowse how to play wave and mp3 files etc. These must be set up, or the pb command won't work. It will say something like, "I don't know how to process an mp3 file". This is consistent with other browsers, which use "plugins" to play multimedia files that are retrieved from the internet.
Keywords: <> Advanced parsing: <-> Language: <en> Search now: <GO> Cleaar form: <RESET>
The first line in this sample form is a simple text field, which is initially empty. You supply the keywords to search for. Entering and editing input fields is discussed later.
The second line is a checkbox. This field tells the search engine to use advanced boolean features, such as this keyword and that, or this, but not that, etc. The feature is disabled, indicated by -. (Most people don't know how to use advanced search anyways.) A + means the checkbox is on.
The third line determines the language of the keywords, English by default. This isn't a free text field, you can't just type in anything you want. We'll describe how to view the options later.
The fourth line is the submit button, which sends the form to the search engine and retrieves the results. This "field" cannot be edited; it is merely a button to push.
The fifth line is also a button to push. It clears all the data you have entered, so you can start over. Default values will be restored. Thus the third line goes back to <en>, rather than <>.
If there is only one input field on the current line, i? displays information about that input field. If the line contains multiple input fields, you will need to use a number, as in i3? for the third field. The type of input field is displayed, then its size, then the field name. If the input field is drawn from a set of options, the option list is displayed as well, with menu numbers prepended. When you want to select an option, you can either type in a substring that determines that option uniquely, such as mich for Michigan, or you can type in its menu number. Needless to say, the latter is often easier. Recall the sample form in the previous section. If you type i? at the third field, you might see the following.
select[7] language 1: english 2: french 3: german 4: italian 5: spanish
If a select list contains hundreds of options, type i?string to see only those options that contain the specified string. Type I?mi in a state field and get Michigan, Mississippi, Missouri, and Minnesota. Then you can select the option you want by name or by number.
Now let's do some data entry. Type i=xyz to place xyz in the input field. Remember, you will need to type i3=xyz to put information into the third input field on the current line. If you get an error, it is probably because the field has a fixed set of options, and you didn't pick one of those options. You can either type in one of the options or its menu number. You can also type in a fragment of the option you want, and edbrowse will fill in the rest. This is done whenever one and only one option contains a copy (case insensitive) of the string you entered. Thus you could enter tali above and get Italian, as that is the only language with those four letters. This is useful when you are entering your address, and they ask for the state. Type in a few letters of your state name, enough to be unique, and you'll probably glom onto the correct option in the list. Note the paradigm here: blind people don't want to wade through a menu unless they absolutely have to!
There is some ambiguity when the option is itself a number. In this case I perform three matches. If you type in the number exactly as it appears, that option is selected. If the number you entered is not a perfect match for one of the options, it is treated as a menu number. If it is not a valid menu number (e.g. out of range), I perform a partial match on the options, looking for those digits as a substring. This may seem confusing, but it is usually what you want.
You can use i<7 to pull the contents of session 7 into the current input field. Session 7 must have one line of text. Similarly, i<filename reads the contents of the file into the current input field. Again, the file should contain one line of text. The filename is expanded in the usual way. This includes wildcard expansion, as long as the expansion leads to one and only one file. Put enough characters around the * to designate a single file.
Now suppose you are entering your credit card number, all 16 digits, into a free text field. If you've made a typo, you don't really want to enter the entire string again. No problem -- use the substitute command. You can write this as i/x/y/ or s/x/y/ -- as you prefer. Remember, you may need to specify a field, as in s3/x/y/. The usual substitution syntax is honored. Don't overgenralize the g suffix in your mind. s3/x/y/g changes every x to y in the third input field, but does not affect the other fields on the current line.
If the submit button is the third field on the current line, you can press it via i3*. However, i* is sufficient when there is only one button on the line. Similarly, you can establish a text field by entering i=kangaroo, rather than i1=kangaroo, if the second field on the current line is a submit button. You only need specify a field number when there are multiple input fields, or multiple buttons, on the current line.
The lynx implementation of the text area is particularly hideous. This is not surprising, since lynx is not an editor. You can correct small typos on the current line, but you can't actually "edit" the text you are working on. Once you hit return, that line is done, and you're on to the next line. You can't move lines around or insert lines etc. Nor can you prepare your comments ahead of time and read them into the text area from a file.
In edbrowse, the text area is managed from another editing session. This allows you to use the full power of the editor. You can move text, make global substitutions, or read comments in from a prepared file. The editing session is chosen for you, and appears in the input field. Consider the following form.
Enter your email address: <> Enter your comments: <buffer 2>
In this example, session 2 was not active when browsing began. The browser allocated session 2 specifically for this input field. Type e2 to move to session 2, prepare your comments, and type e1 to return to the input form. On most web pages the text area starts out blank, whence buffer 2 will be empty, but this is not always the case. Be sure to check for pre-existing text before you start typing your thoughts. A particularly arrogant site might preload the text area with: "I love your website because:".
When you finally submit the form, as discussed in the next section, text buffer 2, associated with the second editing session, will replace the words "bufffer 2" in the input field. Thus your carefully crafted comments are on their way. (This doesn't mean anybody is going to listen to them.)
The submit button sends the form to the remote server and waits for a response. This is similar to following an internet link, but in this case you are sending some data along with the request. Type "kangaroo" into a search engine and you'll soon be reading a web page about kangaroos. As with any other link, you can use the ^ key to go back. In this case you will return to the on-line form. You can change the data and submit the form again, asking about another animal.
I have implemented the "get" and "post" methods, the most common http protocols, and they seem to work on most sites.
Once you have submitted your form, and you are viewing the results, you may notice some strange characters at the end of the filename. If you have retrieved information on kangaroos, the filename might look like: www.search-engine.com?keywords=kangaroo. The text after the question mark is an encoded version of the data you entered into the form. It becomes part of the virtual URL. This is actually a good thing, as we shall see in the next section.
< b this.that.com/whatever # browse a web page
> 16834 # size of the raw html
> 7855 # size of the browsable text
< /kangaroo/i # looking for kangaroo on the page
> Click here for {more information about kangaroos}, or {send us mail}.
< A # capture the URLs
> 144 # size of the URLs
< ,p # let's see them
> <A HREF=www.kangaroo-info.com>
> more information about kangaroos
> </A>
> send us mail:info@kangaroo.org
< 4d # don't need the email address
< w+ $bookmarks # append this url to the bookmark file
> 336
< ^ # back to browsing
> Click here for {more information about kangaroos}, or {send us mail}.
I suppose I could interrogate the environment variable $bookmarks myself, and append the URL to that file automatically, but as this example shows, you might not want all the links. In fact the email link makes no sense in a bookmark file. Also, you may want to change the description of the link, though in this example the description is pretty reasonable.
Alternatively, you might discard the url and retain the email address, appending it to your address book. Again, you will want to change the generic phrase "send us mail" to a brief string that is meaningful to you, such as kangaroo-mail. This becomes the alias, which you can use to send mail to that recipient. (Subsequent sections describe the use of edbrowse as a mail client.)
If there are no links on the current line, or you are not in browse mode, the current filename is used. This is useful when you want to bookmark the current page, rather than some other page pointed to by a link.
If the current page is the result of a form submition, the filename may include your input fields after the question mark. If it does, that's a feature, not a bug. This exact URL, with the data at the end, can be stored as a bookmark and activated again and again, as though you had filled out the form each time. Every week you can call up this virtual URL to see if there is any new information on kangaroos. A more practical example might be a canned query that retrieves the weather for a certain city or the stock prices for the companies in your portfolio. You can also write concise scripts that "fill in" the virtual form, simply by modifying the information after the question mark. This provides a simple command to retrieve the weather from any major city or the current price of any stock.
If the form uses the post, rather than the get method, the same data will appear, but the question mark is replaced with a control a. Unfortunately the control a is not visible, and this could cause confusion. When in doubt, list the line.
One last warning about adding links to your bookmark file. Let's say you've issued your A command, and tweaked the description a bit. Now the link is just write, and you want to save it. You accidentally type `w $bookmarks', forgetting the plus. Instead of apending the link to the end, you have clobbered your entire bookmark file. Years of accumulated links are gone. To avoid this disastrous typo, create a macro to append to your bookmark file. I know, we haven't talked about user defined macros yet, but we will. And when we do, you should write a "bookmark append" macro that looks like this.
function+bma {
w+ $bookmarks
}
Now you can type <bma to add a link to your favorites, and you don't have to worry about typos. It's shorter than `w+ $bookmarks' anyways. We'll return to this topic when we introduce macros, actually functions, that are defined in your config file.
Note that only Netscape-style cookies are supported. However, this is the most common flavor of cooky. It will probably meet your needs.
Persistent cookies are stored in a file, usually $HOME/.cookies, and are thus available for subsequent edbrowse sessions. These cookies are used to store long-term information about you, such as your login and password into amazon.com. Hence your .cookies file should be mode 0600. In fact the file is created mode 0600, for your own protection.
You probably won't need to view your .cookies file, ever, but it is text based, and can be edited directly if you wish.
Edbrowse will verify ssl connections, if you supply a file of ssl certificates. This is an antispoofing measure, to make sure a hacker isn't posing as your bank, trying to steal your account numbers and passwords. You can grab a certificate file here, but I don't always keep it up to date. If you don't have this file, or, if you don't specify its location in your config file, you will not be able to verify secure connections, and you will be warned accordingly. Some browsers don't have this feature at all, so it's not the end of the world, but in general it's a good idea to verify your secure connections, unless it prevents you from getting to a website whose authenticity you accept at face value. In that case you can use the vs command to turn the feature off. This is a toggle command; type vs again to turn the feature on.
Never send sensitive information, such as social security numbers or credit card numbers, over an insecure channel. Make sure the form is using ssl. How can you tell? The submit button will have the word "secure" added to its text.
<Make your purchase now secure>
This is similar to the lock icon that Explorer uses to tell you that your connection is secure, although my system is not quite as foolproof. A website could fake you out by putting the word secure in the submit text.
Note that generic buttons (besides the submit button) can also submit your form, through javascript. I don't know if that button is going to submit the form or not, and I don't want to put the word "secure" on every button on the page. I only add it to the submit button, but if that button is secure then they are all secure. They all use the same form, and the same url.
In theory, it is possible for javascript too switch the destination url out from under you at the last minute, from https://this.is.safe.com to http://this.is.untrusted.com. I don't know if other browsers watch for this bait-and-switch, but edbrowse does. If the original url was secure, and I reported this to you via <submit secure>, and javascript changes it to an insecure connection, I won't submit the form. This is really paranoid, because the first website, the one that asked for your credit card number, also supplies the javascript, and they have no incentive to breech security, since you're going to hand them your credit card number anyways.
If you have logins on secure servers, such as PayPal.com, you must keep your password absolutely safe. Never send that password over an insecure connection. It becomes as valuable as your credit card numbers. I have a special password that I use for my secure logins, and only for those logins. I use other, expendable passwords when the connection is not secure.
Please don't fall for all those email scams that tell you your login has expired, and would you please log in again using this convenient form. The mail is forged to look legitimate, and the form actually sends your secret password to a thief, who then rades your account. A reputable company will never, never, never, ask you to login through an email form. They will always tell you to go back to the website and log in there.
Internet security is complex, to say the least, and it is beyond the scope of this document. If you have any questions about it, please send them to me directly. As a general rule, secure http is really quite safe, and you can use it to send sensitive information across the Net. It's probably safer than giving your credit card number to the clerk on the phone, who use to take your order before there was e-commerce. so it's ok to be a little bit paranoid, in fact it's probably a good idea, but don't let that stop you from making your online purchases.
ftp download
some stats on the size of the file and the bits per second
success
Of course the download could fail, in which case you will receive an error message. If it was simply interrupted, due to some internet glitch, you can issue the command again, and edbrowse will resume the download from where it left off. This can save time when fetching a large file.
By default, edbrowse uses the account name "anonymous" and the password "some-user@edbrowse.net" for ftp connections. However, you can override this in the url, and some web pages take advantage of this feature. For example, let's say you want to access the file /etc/passwd on whatever.localdomain. This file isn't readable by anonymous users. You have to log in as a real person. Within edbrowse, you might use the command:
e ftp://chris:xxx@whatever.localdomain/etc/passwd
The ftp connection will be made as user "Chris", with password "XXX".
Some ftp URLs point at directories, not files. If you visit one of these, and it is located on a Unix-like server, you will receive the listing as an html file with hyperlinks. You can visit the directory members just as though you were exploring a website. If the server does not run some flavore of Unix, you will receive the directory listing in plain text.
The ftp mode, i.e. the style of data connection, can be either active or passive. One works well when the client is behind a router, and the other works well when the server is behind a router. You can specify ftp mode active by entering the command `fma', or ftp mode passive by `fmp'. The command `fmd' sets the ftp mode to a default, which tries to establish a passive connection first, and then an active connection as a fallback. This is a reasonable default, so you should probably leave this alone.
Edbrowse doesn't actually establish the ftp connections, rather, it invokes the program ncftpget to fetch the file, and ncftpls to list the directory. These programs are distributed with most Unix systems. If you don't have these programs, please visit ncftp.com.
Once again, review the differences. Http pulls a file into a buffer in memory, i.e. an edbrowse session, while ftp copies the file directly to disk. Also, ftp does not print dots every 100K to indicate progress, so you just have to wait until it's done. (Depending on your operating system, you could switch to another virtual console/window and check on the length of the local file.)
A page of frames might look like this. I think you can guess which one to click on.
Frame {navigation}
Frame {main}
Frame {bottom}
I thought about a FetchFrame feature that fetches all the frames and presents them in one go, just as they are all displayed on the screen for a sighted user, but this feature is very difficult to implement, and so far, nobody seems to want it. So as you might imagine, it's way down on the list.
The first version of edbrowse, written in perl, ignored javascript completely, and that was ok for a while, but more and more sites use javascript, and these websites were simply inaccessible. Most of the e-commerce sites fall into this category. If you want to make purchases, or manage your bank account online, you need a javascript enabled browser.
The second version of edbrowse, written in C, and indicated by a version number that starts with 2, included a home grown javascript compiler and engine that I wrote myself. This worked pretty well, for a spare time project, but javascript evolves, like any other language or standard, and I just couldn't keep up.
The third version, which is the "latest and greatest", uses a javascript engine from Mozilla.com, which is open source under the Mozzilla Public License. This allows me to leverage, rather than reinvent, some 70,000 lines of code - and somebody else is maintaining that code as javascript evolves. this illustrates the power of the open source community.
Edbrowse does not support all the features of client side (DOM) javascript, and it never will. For example, many websites use javascript to change images on the fly as you move your mouse around the screen. This has no meaning in edbrowse. Other websites bring up multiple windows, and let you control the contents of subwindows using icons in a master window. This would be very difficult to simulate in a command-line environment - so we don't try.
As a rough approximation, I expect to implement about half of javascript, the half that will satisfy 95% of the websites we care about. So you may see warning messages about this or that feature not supported. If you are tired of wading through these messages, or if a bug in my javascript interpreter causes edbrowse to crash completely, you can turn javascript off via the `js' command. This is useful when you are casually surfing the net, looking for information, and you know you're not going to need javascript. You can also disable javascript for specific domains. This will be discussed later, when we describe the edbrowse config file.
In some cases the javascript function reformats your data. It may fill in some of the "hidden" fields for you, or it may compute sales tax and adjust the purchase price accordingly. This is more than form validation, this is active javascript, and the data won't be right unless the javascript runs properly on your computer. More and more sites are using active javascript, so a javascript enabled browser is a must.
Some javascript functions manage menus dynamically. Make a primary selection, and javascript populates a second dropdown list with options corresponding to your first selection. You can now make a second selection, which further refines your search. If the first menu presents "meats", "vegetables", "fruits", and "grains", and you select fruits, the second menu might contain "apples", "oranges", "lemons", etc. Javascript makes this possible. Unfortunately these dynamic menus are not yet supported by edbrowse.
You have a distinct advantage over all those other surfers with their graphical browsers. The popup window does not open automatically. Windows are not well defined in a command line browser anyways, so it would be folly to try to implement this feature, or any other aspect of multi-windowing for that matter. Instead, the popup appears as a hyperlink at or near the top of the page, and you can click on it if you like, or ignore it. This is similar to the background music, described in an earlier section. The popup link might look like this.
{Popup: specials()}
Popunders are not as common. They appear after you have closed the window. In some sense they are hidden "under" your web page, and when you close the page they pop out. In edbrowse, this does not happen automatically. When you type q, you quit, and that's the end of it. As you might expect, the popunder function appears as a hyperlink. It might look like this.
{On Close: foo()}
Remember, the popup link is a simple html link to another web page, while the Close link calls a javascript function on the current page. However, this javascript function usually links to another web page, so don't be surprised if you find yourself somewhere else on the internet. In either case, popup or popunder, you can use the back key to return to the page you were looking at. If you need access to a popup window and the main page in parallel, use the M command.
Javascript also includes timer functions, that fire after a specified number of seconds. These are implemented as hyperlinks at the top of the page. They usually manage visual effects, and are rather pointless. The following timer might draw a star burst on the screen in 16 seconds.
{Timer 16: starburst()}
This is all well and good, but edbrowse has something your graphical browser does not, the undo command. And in this context, it doesn't really work. Change fruits to vegetables, and the second menu presents carrots and peas and the like. Now type u for undo, and the first field reverts back to fruits, but the second menu still contains vegetables. This is because the undo feature was originally written for the text editor. It simply puts the text back the way it was, and has no capacity to "undo" the side effects of javascript code. So the moral of the story, if there is one, is to set and change the values of an input form directly, and avoid the undo command, unless you're pretty sure there are no javascript side effects associated with that field.
The config file is in $HOME/.ebrc. The "eb" is shorthand for edbrowse. You cannot rename the config file; it is what it is. This is true on Windows as well, so make sure HOME is set.
The config file is line oriented. Lines begining with # are comments, and are ignored. Blank lines are also ignored. All other lines fall into one of 5 categories.
Recall the section on cookies. You'll need a file, often called a cookie jar, to store your cookies. The line that establishes this cookie jar might look like this.
jar = /home/eklhad/.ebsys/cookie-jar
This is a simple keyword = value syntax. It's ok if the filename has embedded spaces, or even an equals sign. No need to quote it.
When edbrowse sees this line in its config file, it records the location of the cookie jar, and it checks the validity of that file. If the file is a directory (or something weird), or is otherwise inaccessible, edbrowse prints an error message and aborts. If this happens, use the -c option to edit your config file, and change the cookie jar.
Here are some additional name=value directives. Some of these are used to set up an email account. This will become clearer when we talk about the mail client.
certfile = /home/eklhad/.ebsys/ssl-certs
Specify the file that holds the certificates for secure connections. This was explained in the section on secure connections.
maildir = /home/eklhad/mbox
Go to this directory when fetching mail. thus, if you save a mail message, you'll always know where it is.
webtimer = 30
mailtimer = 180
Wait 30 seconds for a response from a web server, and 3 minutes for a response from the mail server. A time value of 0 waits forever. Sorry, there seems to be no way to interrupt a socket call, other than control backslash (quit), which kills the entire program. That's why these timers are here - so you don't hang forever. The defaults are 20 and 0 respectively.
nojs = space.com
Specify domains that don't need javascript. You can eliminate annoying error messages and speed up access by disabling javascript for certain websites. Javascript will not be run on pages within these domains, nor will it be fetched from these domains.
The above directive will also drop javascript from subdomains such as www.space.com.
You can include a path or partial path after the domain, as in space.com/popups. This will block the popup ads that you don't want to see, and often generate edbrowse errors in any case. Subdomains are not considered when a path is given; the domain must match exactly.
inserver = pop3.some-domain.com
inport = 110
outserver = smtp.some-domain.com
outport = 25
Specify the machines and ports that you use to fetch mail and send mail respectively. You can use the fully qualified domain names, or aliases, as defined in /etc/hosts. The ports shown here are standard, and almost always correct. They are also default in edbrowse, so you need not set inport and outport unless they are different from that shown above. Note, these keywords are only valid in the context of a mail account, as indicated by mail{}.
login = eklhad
password = secret
Specify the login and password that edbrowse uses to fetch your mail.
from = Karl Dahlke
reply = karl.dahlke@some-domain.com
These lines are added in to the emails that you send. They tell the recipient who you are, and how to reply. It is illegal to use these lines for deceptive purposes. Make sure they identify you, and that the reply address is indeed one of your email accounts.
adbook = /home/eklhad/.ebsys/address-book
When specifying recipients, you can use aliases instead of full email addresses. Aliases are checked against your address book, a line oriented text file that is specified here. If your address book contains the line
fred : fred.flintstone@bedrock.us : 226 cobblestone way : 5553827
then you can use the alias fred, and edbrowse will substitute Fred's email address when sending mail. Only the first two fields in the address book are significant as far as edbrowse is concerned. Other fields might hold phone/fax numbers, street address, etc. It's up to you.
spamcan = /home/eklhad/.recycle/save-spam
There is no perfect spam filter. But I can't live without one, so I wrote a simple ip blocker. (This is discussed below.) When spam is received, edbrowse prints the line "spam from such and so", and saves the mail in this file. If you recognize the name, spam from your friend, you can call up this file, find the email, and read it. This should not happen, as there is no particular reason to block the ip address of your friend's computer, but hey, better safe than sorry.
ipblack = /home/eklhad/.ebsys/ip-blacklist
A line oriented text file holds the ip addresses of known porn/spam sites. The syntax is the usual: numbers separated by dots, with an optional /xx netmask indicator at the end. If the file contains the following two lines, any ip address that starts with 192.168, or 10.11.12.13, are forbidden addresses.
192.168.0.0/16
10.11.12.13
If an email refers to a website that resolves to any of these addresses it is considered spam, and flagged as such. Let's be clear; I am not blocking email that comes from certain sources. After all, your friend's computer may well be sending you viruses or spyware. Rather, I screen email that has certain urls in its body. If the button that says "cheap meds for you" leads to a forbidden website, you'll never see the email.
Note, I use the very same blacklist in my firewall. A shell script reads in the addresses and issues the appropriate iptables commands. My file has some 2,000 entries. This is large, but manageable. If the list gets much larger, I may rebuild the kernel with the "large ip tables" option enabled. This makes packet matching more efficient when there are many rules. I suppose it sorts them or something.
All well and good, but some websites have no respect for edbrowse, or lynx for that matter. They won't even let you in the door unless you look like Explorere or Netscape. Clickbank.com, a major credit card processor, is one example.
So what do we do? We lie!
You can specify different agents in your .ebrc file, and activate them with the `ua' (user agent) command. If the following lines are in your .ebrc file, you can type ua1 to pretend to bee lynx, and ua2 to pretend to be Mozilla. Type ua0 to resurrect the standard edbrowse identification. Let's hope there aren't too many asinine websites out there, like Clickbank, that force us to lie. It's just so stupid, and pointless.
agent = Lynx/2.8.4rel.1 libwww-FM/2.14
agent = Mozilla/4.0 (compatible; MSIE 5.5; Windows 98; Win 9x 4.90)
This feature was written pre-javascript, and is not 100% compatible with the navigator object. Navigator.userAgent returns the correct string, according to the agent you select, but other aspectss of the navigator object do not change with the agent, and they should.
function:ud {
,s/\r$//
}
The new < command is suppose to remind you of redirection, i.e. read input commands from this macro. And macros can invoke other macros, by using a < command in the body. Almost any edbrowse command is fair game. A macro can fetch web pages from the internet, fill out forms, submit requests, and send mail.
Normally, edbrowse marches along, whether a command succeeds or not. However, you can tell a macro to stop if it encounters an error by using this syntax.
function+hw {
/hello/p
/world/p
}
The plus sign after the word function means each command in that function must succeed. If there is no line containing the word hello, the function stops. If there is such a line, then the function moves on, and looks for a line containing the word world.
Other than some indenting, the format is fixed, and unforgiving. You cannot, for instance, put the opening brace on its own line, as K&R would suggest.
These functions, or macros, can accept parameters. Let's make the previous function a bit more general.
function+hw {
/~1/p
/~2/p
}
You can reproduce the earlier behavior by typing <hw hello world. Or you can search for different lines by invoking <hw foo bar. The latter looks for a line containing foo and prints it, and if this succeeds it looks for a line containing bar and prints that. Let's build a more useful function, a shortcut to google. The variable ~0 represents all the arguments together. In this case ~0 is the keywords you pass to google, for your search.
function+gg {
b www.google.com/search?q=~0&hl=n&btnG=Google+Search&meta=
}
With this in place, you simply type `<gg kangaroo habitat' to find out where kangaroos live.
Finally, an edbrowse function can branch, based upon the success or failure of the previous command. Use if(*) for success, and if(?) for failure. The ? is suppose to remind you of the question mark that you get when an edbrowse command fails. The following looks for a line containing foo, and if it finds one, it advances to the next line, and if that line contains bar, it deletes it.
function+silly {
/foo/
if(*) {
+s/bar//
if(*) {
d
}
}
}
I deliberately used function+ instead of function: in the above example. Normally the + will cause the function to abort if an edbrowse command fails. However, if the result of that command is used by a control statement, the function does not abort. This is similar to set -e in the shell, which causes a script to abort, unless the result of the command is used by an if statement.
Other control statements include while(*) while(?) until(*) and until(?). The following deletes lines from the top of the file, as long as they contain foo or bar. It then deletes the blank lines at the top.
function+topclean {
until(?) {
1g/foo\|bar/d
}
until(?) {
1g/^$/d
}
}
You can use loop(100){ ... } to repeat a set of commands 100 times. I haven't used this feature very often.
function+init {
# turn debug off, so we don't see any status messages from this script
db0
# Assume directories can be modified
dw
# Put beginning and end markers around listed lines
el
# Let session 99 hold your favorites, ready to surf.
e99
b $bookmarks
# back to session 1, ready to go to work
e1
# Restore debug level to something reasonable, 1 or 2
db1
}
This is just a sample. Put anything you like in your init script, or leave it out altogether if you are happy with edbrowse out of the box.
We already discussed the relevant keywords for an email account. All you have to do is enclose them in mail{...}, like this.
mail {
default
inserver = pop3.some-domain.com
outserver = smtp.some-domain.com
login = eklhad
password = secret
from = Karl Dahlke
reply = karl.dahlke@some-domain.com
}
The "default" directive makes this account the default. One and only one account should be labeled default. If you do not specify an account when fetching or sending mail, the default account is used. Beyond this, the default smtp server is always used to send mail, no matter which account you specify. If account #1 is default, and you send mail using account #3, the name and reply address from account #3 will be sent to the recipient, and if he replies, his reply will be sent to your third email account. However, the smtp server from your default account is always used to physically transmit the message. There are technical reasons for doing this, that are beyond the scope of this document. Trust me, it's the right thing to do.
Mail filtering, by sender and/or subject, is controlled by your config file as well. This will be described later, as part of the fetchmail client.
mime {
type = audio/mp3
desc = audio file in mp3 format
suffix = mp3
program = mpg123 -q -
}
If you have pulled down a file from the internet that ends in .mp3, type `pb' to play the contents of the buffer. The data is piped into the program, whose options tell it to expect data from standard in. If the mp3 player works better from a file, use a trailing percent to turn the buffer into a temp file with the proper suffix.
program = mpg123 -q %
The command `pb' could mean process buffer,as well as play buffer. For instance, a mime descriptor might unzip a zip archive.
mime {
type = data/zip
desc = a compressed zip archive
suffix = zip
# use %, since unzip cannot read data from standard in
program = unzip %
}
The contents of your .signature file, in your home directory, are automatically appended. This is standard behavior for Unix mail clients.
The recipients, attachments, and subject must appear at the top of your file. The sm command is picky, so observe the following syntax carefully.
To: fred.flintstone@bedrock.us To: barney.rubble@bedrock.us account: 1 attach: hollyrock-brochure.pdf Subject: Hollyrock Vacation Come visit Hollyrock. Brochure attached. Sincerely, Rock studios incorporated.
The account line is optional. It tells edbrowse to use the first mail account specified in your .ebrc config file. If you don't include an account: line, edbrowse uses the default account, indicated by "default" in your .ebrc file.
Typing sm5 causes edbrowse to use account number 5 in your config file. This overrides the account: line in your file, if there is one. It is often easier to type sm5 than to insert an account:5 line. Note, sm-5 is the same as sm5, but the .signature file is not included. Sometimes you want a different ending on your email, for a particular situation.
Use the attach: lines to add attachments to your email. Each line should specify a file to attach, and they must appear before the subject line. If the filename is simply a number, the corresponding edbrowse session is used instead. Return to the earlier example, where we are trying to attach a Hollyrock brochure. Another way to do this is to switch to session 2 and read in the pdf file. This is a binary file, but that doesn't matter. Don't try to edit it, just hold it in session 2. Then switch back to session 1 and use the line attach:2.
If you use attach:2, instead of attach:hollyrock-brochure.pdf, Fred will notice one difference. The attachment is not prenamed for him. If he wants to save the attachment, he'll have to come up with a filename himself. Other than that, the email looks the same.
The alt: directive is almost the same as the attach: directive. If you use alt:, the attachment is not treated as an adjunct file. Instead, it is an alternate representation of the same email. The mail client will use the alternate representation if it can. This is usually used to send multimedia email, with hyperlinks and pictures etc. The primary email is in plain text, but the alternate attachment is in html or rich text. Unless something is amiss, the user sees the alternate presentation, complete with graphics and hyperlinks.
Like attachments, the alt: line can refer to a file or an edbrowse session.
As you may have guessed, the to: lines establish the recipients. Please don't specify more than a few recipients. Some servers, my mail server included, set a hard limit on the number of recipients. If you exceed this number, somewhere between 10 and 100, the remaining recipients simply don't get their mail. Best to limit your "to:" lines to 10 or less.
When specifying recipients, you can use aliases instead of full email addresses. Aliases are checked against your address book, a text file that is specified in your .ebrc file. If your address book contains the line
fred : fred.flintstone@bedrock.us : 226 cobblestone way : 5553827
then you can simply write "To:fred" at the top of your file. Only the first two fields in the address book are significant as far as edbrowse is concerned. Other fields might hold phone/fax numbers, street address, etc.
Note that "Reply to fred" is an alternate syntax for "to: fred".
Some web pages include sendmail links. They look just like other hyperlinks, but they send email to the appropriate person. Click here for technical details.
If you activate a sendmail link, you will be placed in a new editing session with the "to" and "subject" lines preloaded. If the url did not specify a subject, the subject is simply "Hello". You will probably want to replace this with a better subject line. Write your mail message and type `sm' to send it on its way. Then type ^ to return to the web page you were looking at. Note that the body of your email may also be preloaded with some default text, so be sure to check before you write and send.
You can include attachments by placing "attach:" lines at the top of the file, assuming the recipient can handle these attachments. This might make sense when the sendmail link is asking for {bug reports} - you might attach a program and/or its output. Yet this is somewhat unusual. Most sendmail links expect a few sentences of feedback, and nothing more.
Some web forms are submitted via email, rather than a direct http transmission. Edbrowse handles this properly. It shows you the destination email address, sends the mail through smtp, and tells you to watch for a reply. This reply could be an email response, or even a phone call if you provided your phone number in the form. But remember, nothing happens immediately. You are still on the same web page, still looking at the same submit button. Don't push the button again! The mail has been sent, and you'll be hearing from the company in the next few days.
e -m1 fred barney hollyrock-notice +hollyrock-brochure.pdf
Files with the leading + are assumed to be attachments. If they are binary they will be encoded properly, according to the mime standard. A leading - indicates an alternate format, like this.
e -m1 fred barney hollyrock-notice -hollyrock-graphical.html
Remember, you can specify several mail accounts in your .ebrc file. The first account is indicated by index 1, as in -m1, and so on. You can make your life a lot easier with some aliases in your .bashrc file.
# My mail, home account alias mymail="e -m1" # My wife's account. alias wifemail="e -m2" # My work account. alias workmail="e -m3" # mail is obsolete alias mail="echo use mymail, wifemail, or workmail"
? summary of key commands q quit the program x abort the program, deleted mail is not really deleted space display more text n read the next message d delete this message i show referenced ip addresses, then delete this message j junk this message, and any messages with this subject, for 10 days J junk this subject for a year w write this message to a file and delete it k keep this message in a file, but don't delete it u write this message unformatted to a file and delete it
The last three commands, k w and u, require a filename, which you enter. The reserved filename "x" is essentially /dev/null, whence the mail message is discarded. You can save the mail message to x (discard) and still save the attachments. If the file is anything other than x, and the program cannot write to the specified file, it asks you for a new filename.
The junk command adds a filter rule to your config file, sending any message with this subject to oblivion. This is useful when you don't want to read a particular discussion thread in a mailing list. Use the j command to junk it for ten days. If the subject pops up again in two months, you might be interested. Use the capital J command to junk a subject for a year. This is typically used for spam subjects, such as "Cheap meds for you."
Issue the i command when the mail is obviously porn/spam. You will see the ip addresses, which you can add to your blacklist file. This is not done automatically, because I believe in a certain amount of manual control over the process. For example, if you, as a human, notice that you have blocked out 7 addresses starting with 10.16.29, you may want to get rid of those rules and replace them with the single rule 10.16.29.0/24. There is a slight risk in doing this, since a valid address might be nestled in amongst all these spam sites. But it's not likely. In fact, I sometimes take a leap of faith and exclude an entire two-byte block. That's 65,536 websites that are locked out of my computer, for email or browsing. A bit heavy handed perhaps, but I really hate all this spam and spyware crap!
If one of those 65,536 addresses turns out to be valid, use a bang to negate the sense of the address, like this.
10.5.33.177!
10.5.0.0/16
Doing these ip lookups in real-time can slow the process of fetching your mail. You can disable the whole thing by omiting, or commenting out, the ipblack= line in your config file.
IP filtering only works for hyperlinks. If an email has an online form that is submitted to a forbidden site, I don't detect that. I should though - as these are the most dangerous emails of all. They pretend to come from your bank, then send your account numbers to a thief in Russia. So yes, this form of ip blocking is on my list of fun things to do.
Like spam keywording, ip blocking is no panacea. For example, a spammer with half a brain can sign up for http redirection at no cost. Suddenly the domain in the email does not reflect the true destination at all. I could add software to pull down the html page and test for redirection, but that would really slow down the interactive mail process. Beyond this, a spammer can use javascript to assemble his destination url on the fly, and as you know, there is no way to anticipate the actions of a javascript program and pre-determine the destination url. And so, the arms race continues, and just like the real world, the offensive team will always have the upper hand.
When an html mail message is rendered, javascript is disabled. Thus the mail appears sooner, and the mail client is less likely to crash due to a bug in the javascript machinery. There really isn't much loss here, because you couldn't activate the links or fill out the form anyways. If you want to "interact" with this email message, you have to save it unformatted to a file, finish your email session, edit that file, and type b to browse. Now the html is active, as though you were looking at a web page on somebody's site.
There is a reason for this falderal. When you are running edbrowse as a fetchmail client, there is a time limit, imposed by your pop3 server. You have about 20 seconds to decide the fate of each message. Throw it away, skip it, save it to a file, etc. If you doddle, the mail server hangs up and you have to start all over again. This is not the time to interact with your message; this is not the time to fill out forms or follow hyperlinks to other interesting websites. If you are that interested, save the message to a file and move on.
Your sighted friend, running Outlook Express, doesn't have to worry about this, because every message is saved to a file automatically. When he scans his mail, he is actually looking at files that have been transferred to his computer some time in the past. He is not in the middle of a pop3 session, and there are no time limits. This may be a better approach; I don't know. Someday I may add a feature to grab all your messages and copy them to local files in your mail directory. You could then use edbrowse in directory mode to step through each file in turn. Personally, I get a lot of silly little emails, and spam too, so I am happy to delete the majority of my messages as they come, in real time, and save the few that are interesting. Other filtering options can simplify this process. For instance, mail from my friend Dorothy will always be saved in a particular place, because I always want to read that at my leisure. this is described in the next section.
matchString > destinationFile
Actually the > is a bit misleading. If the file exists, the email is appended to the end; the file is not truncated. So perhaps we should use >>, but I didn't want to bother with the extra greater, over and over again.
The destination file is interpreted relative to the mail directory, which is set in your config file. Of course you can override with an absolute path if you wish.
A mail filtering rule always occurs in the context of a filter block. For instance, if you wish to redirect mail from certain people, do this.
fromfilter {
fred flintstone > fredmail
fred.flintstone@bedrock.us > fredmail
jerk@hotmail.com > x
word@m-w.com > -wod
}
You can specify the sender's name, or his email address. It's not a bad idea to do both, in case he sends mail from some other account etc.
Notice that I didn't capitalize Fred Flintstone. Matches are case insensitive.
The file name "x" is special; it discards the mail entirely. You can use this to throw away mail from people who are constantly harassing you, or sending you spam.
The last entry sends mail to -wod. The leading - is special; it means the mail should be saved to wod unformatted. This happens to be the word of the day from Merriam Webster. I like to save it unformatted, so I can browse it, and click on {audio} to hear the word pronounced. If an email contains hyperlinks, you may want to save it unformatted, so you can browse it later.
You can also filter mail based on the to: field. This is useful if you have several mail accounts, or mail aliases that are forwarded to your primary account. Here is a sample block.
tofilter {
support@my-side-business.com > support
sales@my-side-business.com > sales
@my-side-business.com > business
me@my-regular-dayjob.com > work
}
The third entry is a catchall address, saving any mail that is sent to that domain. Since rules are applied in order, support requests are stored in a file called "support", sales are stored in a file called "sales", and all other emails sent to your business are stored in "business".
You can use catchall addresses in the fromfilter block as well. Anything from this domain goes here, etc.
You can filter based on subject, using the subjfilter{...} block. This can close the door on the virus de jure. If a virus uses a subject line of "Come Kiss Me", you can redirect "come kiss me" to x, and it's gone.
You can also use this feature to block warnings from other ISPs, complaining that you sent them emails with virus attachments. You didn't, of course, because you run linux. You're immune! Your reply address was forged, so the virus warning was sent back to you, but you really had nothing to do with it. Lines like this one can throw these spurious warnings away.
subjfilter {
Come Kiss Me > x
Net Integrator Virus Alert > x
}
Finally, the reply address is checked against your address book. If there is a match, the mail is saved in a file whose name is the email alias. Consider a line in your address book that looks like fred:Fred.Flintstone@SomeDomain.com. When you receive email from this particular address, it is saved to the file fred. Thus you don't have to enter and maintain redundant entries in the filter. There is no need to include Fred.Flintstone@SomeDomain.com > fred. It's taken care of.
If you want to save mail from Fred unformatted, place a minus sign, i.e. -fred, in your address book. This is the same convention as the from filter. If you don't want mail from Fred to be redirected, but you still want to use the alias fred when sending mail, place an exclamation mark at the start, i.e. !fred.
Note that mail filtering occurs before spam detection. Thus mail from your friend, or to your business, will always be saved in a file, even if it references a forbidden website.
If an email is redirected to a file, and it includes attachments, edbrowse will ask you what to do with those attachments, as though you had used the w command to save the mail yourself. If your friend has send you a program (attached) that he wants you to look at, just hit return to save it to the default filename. If your friend's mail has some kind of logo, or background image, that you don't care about, just type x and it will go away. If the image has a recognizable suffix, such as gif, I discard it automatically. If you really want these images, you'll have to save the email unformatted, and browse it later.
Use the -p option to pass over the filters, as in `e -pm1'. This also stops spam detection. I set this when looking at other people's mail, such as my wife's account. I don't want her mail sent somewhere else because it matches one of my filter rules.