Copyright (C) 1989, 1991 Free Software Foundation, Inc. 675 Mass Ave, Cambridge, MA 02139, USA Everyone is permitted to copy and distribute verbatim copies of this license document, but changing it is not allowed.
The licenses for most software are designed to take away your freedom to share and change it. By contrast, the GNU General Public License is intended to guarantee your freedom to share and change free software--to make sure the software is free for all its users. This General Public License applies to most of the Free Software Foundation's software and to any other program whose authors commit to using it. (Some other Free Software Foundation software is covered by the GNU Library General Public License instead.) You can apply it to your programs, too.
When we speak of free software, we are referring to freedom, not price. Our General Public Licenses are designed to make sure that you have the freedom to distribute copies of free software (and charge for this service if you wish), that you receive source code or can get it if you want it, that you can change the software or use pieces of it in new free programs; and that you know you can do these things.
To protect your rights, we need to make restrictions that forbid anyone to deny you these rights or to ask you to surrender the rights. These restrictions translate to certain responsibilities for you if you distribute copies of the software, or if you modify it.
For example, if you distribute copies of such a program, whether gratis or for a fee, you must give the recipients all the rights that you have. You must make sure that they, too, receive or can get the source code. And you must show them these terms so they know their rights.
We protect your rights with two steps: (1) copyright the software, and (2) offer you this license which gives you legal permission to copy, distribute and/or modify the software.
Also, for each author's protection and ours, we want to make certain that everyone understands that there is no warranty for this free software. If the software is modified by someone else and passed on, we want its recipients to know that what they have is not the original, so that any problems introduced by others will not reflect on the original authors' reputations.
Finally, any free program is threatened constantly by software patents. We wish to avoid the danger that redistributors of a free program will individually obtain patent licenses, in effect making the program proprietary. To prevent this, we have made it clear that any patent must be licensed for everyone's free use or not licensed at all.
The precise terms and conditions for copying, distribution and modification follow.
Activities other than copying, distribution and modification are not covered by this License; they are outside its scope. The act of running the Program is not restricted, and the output from the Program is covered only if its contents constitute a work based on the Program (independent of having been made by running the Program). Whether that is true depends on what the Program does.
You may charge a fee for the physical act of transferring a copy, and you may at your option offer warranty protection in exchange for a fee.
These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it.
Thus, it is not the intent of this section to claim rights or contest your rights to work written entirely by you; rather, the intent is to exercise the right to control the distribution of derivative or collective works based on the Program.
In addition, mere aggregation of another work not based on the Program with the Program (or with a work based on the Program) on a volume of a storage or distribution medium does not bring the other work under the scope of this License.
The source code for a work means the preferred form of the work for making modifications to it. For an executable work, complete source code means all the source code for all modules it contains, plus any associated interface definition files, plus the scripts used to control compilation and installation of the executable. However, as a special exception, the source code distributed need not include anything that is normally distributed (in either source or binary form) with the major components (compiler, kernel, and so on) of the operating system on which the executable runs, unless that component itself accompanies the executable.
If distribution of executable or object code is made by offering access to copy from a designated place, then offering equivalent access to copy the source code from the same place counts as distribution of the source code, even though third parties are not compelled to copy the source along with the object code.
If any portion of this section is held invalid or unenforceable under any particular circumstance, the balance of the section is intended to apply and the section as a whole is intended to apply in other circumstances.
It is not the purpose of this section to induce you to infringe any patents or other property right claims or to contest validity of any such claims; this section has the sole purpose of protecting the integrity of the free software distribution system, which is implemented by public license practices. Many people have made generous contributions to the wide range of software distributed through that system in reliance on consistent application of that system; it is up to the author/donor to decide if he or she is willing to distribute software through any other system and a licensee cannot impose that choice.
This section is intended to make thoroughly clear what is believed to be a consequence of the rest of this License.
Each version is given a distinguishing version number. If the Program specifies a version number of this License which applies to it and "any later version", you have the option of following the terms and conditions either of that version or of any later version published by the Free Software Foundation. If the Program does not specify a version number of this License, you may choose any version ever published by the Free Software Foundation.
If you develop a new program, and you want it to be of the greatest possible use to the public, the best way to achieve this is to make it free software which everyone can redistribute and change under these terms.
To do so, attach the following notices to the program. It is safest to attach them to the start of each source file to most effectively convey the exclusion of warranty; and each file should have at least the "copyright" line and a pointer to where the full notice is found.
one line to give the program's name and an idea of what it does. Copyright (C) 19yy name of author This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
Also add information on how to contact you by electronic and paper mail.
If the program is interactive, make it output a short notice like this when it starts in an interactive mode:
Gnomovision version 69, Copyright (C) 19yy name of author Gnomovision comes with ABSOLUTELY NO WARRANTY; for details type `show w'. This is free software, and you are welcome to redistribute it under certain conditions; type `show c' for details.
The hypothetical commands `show w' and `show c' should show the appropriate parts of the General Public License. Of course, the commands you use may be called something other than `show w' and `show c'; they could even be mouse-clicks or menu items--whatever suits your program.
You should also get your employer (if you work as a programmer) or your school, if any, to sign a "copyright disclaimer" for the program, if necessary. Here is a sample; alter the names:
Yoyodyne, Inc., hereby disclaims all copyright interest in the program `Gnomovision' (which makes passes at compilers) written by James Hacker. signature of Ty Coon, 1 April 1989 Ty Coon, President of Vice
This General Public License does not permit incorporating your program into proprietary programs. If your program is a subroutine library, you may consider it more useful to permit linking proprietary applications with the library. If this is what you want to do, use the GNU Library General Public License instead of this License.
The program wdiff is a front end to diff for comparing
files on a word per word basis. A word is anything between whitespace.
This is useful for comparing two texts in which a few words have been
changed and for which paragraphs have been refilled. It works by
creating two temporary files, one word per line, and then executes
diff on these files. It collects the diff output and uses
it to produce a nicer display of word differences between the original
files.
Ideally, wdiff should avoid calling diff and do all the
work internally, allowing it to be faster and more polished. However, I
loathe replicating the diff algorithm and development effort,
instead of improving diff itself. It would be more sensible to
integrate wdiff into diff than the other way around. I
did it this way only because I had a sudden and urgent need for it, and
it would have taken too much time to integrate it correctly into GNU
diff. Your advice or opinions about this are welcome.
wdiff was written by Francois Pinard.
Please report bugs to `bug-gnu-utils@prep.ai.mit.edu'.
Include the version number, which you can find by running `wdiff
--version'. Include in your message sufficient input to reproduce the
problem and also, the output you expected.
wdiff
The format for running the wdiff program is:
wdiff option ... old_file new_file
wdiff compares files old_file and new_file and
produces an annotated copy of new_file on standard output.
wdiff will exit with a status of 0 if no differences were found,
a status of 1 if any differences were found, or a status of 2 for any
error.
In this documentation, deleted text refers to text in old_file which is not in new_file, while inserted text refers to text on new_file which is not in old_file.
wdiff supports the following command line options:
wdiff on the standard error output.
wdiff are now put under the control of this option.
By using it, a pager is interposed whenever the wdiff output is
directed to the user's terminal. Without this option, no pager will be
called, the user is then responsible for explicitly piping wdiff
output into a pager, if required.
The pager is selected by the value of the PAGER environment
variable when wdiff is run. If PAGER is not defined at
run time, then a default pager, selected at installation time, will be
used instead. A defined but empty value of PAGER means no pager
at all.
When a pager is interposed through the use of this option, one of the options `-l' or `-t' is also selected, depending on whether the string `less' appears in the pager's name or not.
It is often useful to define `wdiff' as an alias for `wdiff
-a'. However, this hides the normal wdiff behaviour. The
default behaviour may be restored simply by piping the output from
wdiff through cat. This dissociates the output from the
user's terminal.
-p, but also over-strikes whitespace associated with
inserted text. less shows such whitespace using reverse video.
This option is not selected by default. However, it is automatically
turned on whenever wdiff launches the pager less. See
option `-a'.
This option is commonly used in conjunction with less:
wdiff -l old_file new_file | less
termcap strings for emphasising parts of
output, even if the standard output is not associated with a terminal.
The `TERM' environment variable must contain the name of a valid
termcap entry. If the terminal description permits, underlining
is used for marking deleted text, while bold or reverse video is used
for marking inserted text. This option is not selected by default.
However, it is automatically turned on whenever wdiff launches a
pager, and it is known that the pager is not less. See
option `-a'.
This option is commonly used when wdiff output is not redirected,
but sent directly to the user terminal, as in:
wdiff -t old_file new_file
A common kludge uses wdiff together with the pager more,
as in:
wdiff -t old_file new_file | more
However, some versions of more use termcap emphasis for
their own purposes, so strange interactions are possible.
Note that options `-p', `-t', and `-[wxyz]' are not mutually exclusive. If you use a combination of them, you will merely accumulate the effect of each. Option `-l' is a variant of option `-p'.
wdiff usage
This section presents a few examples of usage, most of them have been
contributed by wdiff users.
This example comes from a discussion with Joe Wells, `jbw@cs.bu.edu'.
The following command produces a copy of new_file, shifted right one space to accommodate change bars since the last revision, ignoring those changes coming only from paragraph refilling. Any line with new or changed text will get a `|' in column 1. However, deleted text is not shown nor marked.
wdiff -1n old_file new_file |
sed -e 's/^/ /;/{+/s/^ /|/;s/{+//g;s/+}//g'
Here is how it works. Word differences are found, paying attention only
to additions, as requested by option `-1'. For bigger changes
which span line boundaries, the insert bracket strings are repeated on
each output line, as requested by option `-n'. This output is then
reformatted with a sed script which shifts the text right two
columns, turns the initial space into a bar only if there is some new
text on that line, then removes all insert bracket strings.
LaTeX example.
This example has been provided by Steve Fisk, `fisk@polar.bowdoin.edu'.
The following uses LaTeX to put deleted text in boxes, and new text in double boxes:
wdiff -w "\fbox{" -x "}" -y "\fbox{\fbox{" -z "}}" ...
works nicely.
troff example.
This example comes from Paul Fox, `pgf@cayman.com'.
Using wdiff, with some troff-specific delimiters gives
much better output. The delimiters I used:
wdiff -w'\s-5' -x'\s0' -y'\fB' -z'\fP' ...
This makes the pointsize of deletions 5 points smaller than normal, and emboldens insertions. Fantastic!
I experimented with:
wdiff -w'\fI' -x'\fP' -y'\fB' -z'\fP'
since that's more like the defaults you use for terminals/printers, but since I actually use italics for emphasis in my documents, I thought the point size thing was clearer.
I tried it on code, and it works surprisingly well there, too...