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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. The
empty string or the string `-' denotes standard input, but standard
input cannot be used twice in the same invocation. The complete path of
a file should be given, a directory name is not accepted. 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:
- `--help'
-
- `-h'
-
Print an informative help message describing the options.
- `--version'
-
- `-v'
-
Print the version number of
wdiff
on the standard error output.
- `--no-deleted'
-
- `-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'
-
- `-2'
-
Avoid producing inserted words on the output. When this flag is given,
the whitespace in the output is taken from old_file instead of
new_file. If neither `-1' or `-2' is selected, the
original right margin may be exceeded for some lines.
- `--no-common'
-
- `-3'
-
Avoid producing common words on the output. When this option is not
selected, common words and whitespace are taken from new_file,
unless option `-2' is given, in which case common words and
whitespace are rather taken from old_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 segregated by lines of dashes.
- `--ignore-case'
-
- `-c'
-
Do not consider case difference while comparing words. Each lower case
letter is seen as identical to its upper case equivalent for the purpose
of deciding if two words are the same.
- `--statistics'
-
- `-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'
-
- `-a'
-
Some initiatives which were previously automatically taken in previous
versions of
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.
- `--printer'
-
- `-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'
-
- `-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 the pager less
. See
option `-a'.
This option is commonly used in conjunction with less
:
wdiff -l old_file new_file | less
- `--terminal'
-
- `-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 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'
-
- `-w argument'
-
Use argument as the start delete string. This string will
be output prior to any 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'
-
- `-x argument'
-
Use argument as the end delete string. This string will be
output after any 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'
-
- `-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'
-
- `-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'
-
- `-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'.
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