wdiff - display word differences between text files
SYNOPSIS
wdiff [
option ... ]
old_file new_file
COPYRIGHT
Copyright (C) 1992 Free Software Foundation, Inc.
DESCRIPTION
wdiff compares two files, finding which words have been deleted or added to
old_file to get
new_file. A word is anything between whitespace. The output is collected and
used to produce an annotated copy of
new_file on standard output. Suitable annotations produce a nice display of
word differences between the original files.
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.
Usually underlining is used to mark deleted text, while bold or
reverse video is used to mark inserted text; these defaults may be
over-ridden by command line options.
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.
OPTIONS
--help
Has the same effect as -h.
-h
Print an informative help message describing the options.
--version
Has the same effect as -v.
-v
Print the version number of
wdiff on the standard error output.
--no-deleted
Has the same effect as -1.
-1
Avoid producing deleted words on the output. If neither
-1 or
-2 is selected, the original right margin may be exceeded for some lines.
--no-inserted
Has the same effect as -2.
-2
Avoid producing inserted words on the output. If neither
-1 or
-2 is selected, the original right margin may be exceeded for some lines.
--no-common
Has the same effect as -3.
-3
Avoid producing common words on the output. When this option is not
selected, common words and whitespace are taken from
new_file. When selected, differences are separated from one another by lines of
dashes. Moreover, if this option is selected at the same time as
-1 or
-2, then none of the output will have any emphasis - i.e. no bold or
underlining. Finally, if this option is not selected, but both
-1 and
-2 are, then sections of common words between differences are separated
by lines of dashes.
--statistics
Has the same effect as -s.
-s
On completion, for each file, the total number of words, the number of
common words between the files, the number of words deleted or
inserted and the number of words that have changed is output. (A
changed word is one that has been replaced or is part of a
replacement.) Except for the total number of words, all of the
numbers are followed by a percentage relative to the total number of
words in the file.
--auto-pager
Has the same effect as -a.
-a
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 terminal.
--printer
Has the same effect as -p.
-p
Use over-striking to emphasize parts of the output. Each character of
the deleted text is underlined by writing an underscore _ first, then
a backspace and then the letter to be underlined. Each character of
the inserted text is emboldened by writing it twice, with a backspace
in between. This option is not selected by default.
--less-mode
Has the same effect as -l.
-l
Use over-striking to emphasize parts of output. This option works as
option -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
less. (See option -a.)
This option is commonly used in conjunction with
less: wdiff -l old_file new_file | less
--terminal
Has the same effect as -t.
-t
Force the production of
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's 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.
--start-delete argument
Has the same effect as -w.
-w argument
Use
argument as the "start delete" string. This string will be output prior to
every sequence of deleted text, to mark where it starts. By default,
no start delete string is used unless there is no other means of
distinguishing where such text starts; in this case the default start
delete string is
[-.
--end-delete argument
Has the same effect as -x.
-x argument
Use
argument as the "end delete" string. This string will be output after every
sequence of deleted text, to mark where it ends. By default, no end
delete string is used unless there is no other means of distinguishing
where such text ends; in this case the default end delete string is
-].
--start-insert argument
Has the same effect as -y.
-y argument
Use
argument as the "start insert" string. This string will be output prior to any
sequence of inserted text, to mark where it starts. By default, no
start insert string is used unless there is no other means of
distinguishing where such text starts; in this case the default start
insert string is
{+.
--end-insert argument
Has the same effect as -z.
-z argument
Use
argument as the "end insert" string. This string will be output after any
sequence of inserted text, to mark where it ends. By default, no end
insert string is used unless there is no other means of distinguishing
where such text ends; in this case the default end insert string is
+}.
--avoid-wraps
Has the same effect as -n.
-n
Avoid spanning the end of line while showing deleted or inserted text.
Any single fragment of deleted or inserted text spanning many lines
will be considered as being made up of many smaller fragments not
containing a newline. So deleted text, for example, will have an end
delete string at the end of each line, just before the new line, and a
start delete string at the beginning of the next line. A long
paragraph of inserted text will have each line bracketed between start
insert and end insert strings. This behaviour is not selected by
default.
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.
EXAMPLES
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'
BUGS
If you find a bug in
wdiff, please send electronic mail to
pinard@iro.umontreal.ca. 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 currently calls
diff. wdiff would be quicker and cleaner to implement if it were part of the
diff suite of programs.
Here are some (un-processed) suggestions:
-
Make an MS-DOS port.
-
Select by options exactly what is whitespace.
-
Have a
wpatch program. Hard to see a good way of doing this.
IDENTIFICATION
Author: Francois Pinard,
pinard@iro.umontreal.ca Manual Page: Colin M. Brough,
cmb@epcc.ed.ac.uk Revision Number: (Rv; Release Date: (Dt.