diff

Compare two files, line by line (GNU)

Syntax:

diff [option] file1 file2

Runs on:

Neutrino

Options:

-i
--ignore-case
Ignore case differences in the contents of the files.
--ignore-file-name-case
Ignore case when comparing filenames.
--no-ignore-file-name-case
Consider case when comparing filenames.
-E
--ignore-tab-expansion
Ignore changes due to tab expansion.
-b
--ignore-space-change
Ignore changes in the amount of white space.
-w
--ignore-all-space
Ignore all white space.
-B
--ignore-blank-lines
Ignore changes whose lines are all blank.
-I RE
--ignore-matching-lines=RE
Ignore changes whose lines all match the given regular expression.
--strip-trailing-cr
Strip trailing carriage returns from the input.
-a
--text
Treat all files as text.
-c
-C num
--context[=num]
Output num (default 3) lines of copied context.
-u
-U num or --unified[=num]
Output num (default 3) lines of unified context.
--label label
Use label instead of the filename in the output. You can specify this option twice; the first applies to file1, and the second to file2.
-p
--show-c-function
Show which C function each change is in.
-F RE
--show-function-line=RE
Show the most recent line that matches the given regular expression.
-q
--brief
Output only whether or not the files differ.
-e
--ed
Output an ed script.
--normal
Display the differences in the normal format.
-n
--rcs
Display the differences in RCS format.
-y
--side-by-side
Display the output in two columns.
-W num
--width=num
Output at most num (default 130) print columns.
--left-column
Output only the left column of common lines.
--suppress-common-lines
Don't display any lines that are common to both files.
-D name
--ifdef=name
Output merged file to show #ifdef name differences.
--GTYPE-group-format=GFMT
Use the given format to output groups of lines in an if-then-else format. GTYPE can be old, new, changed, or unchanged.

GFMT may contain:

%<
Lines from file1.
%>
Lines from file2.
%=
Lines common to file1 and file2.
%[-][width][.[prec]]{doxX}letter
Use the given printf-style specification for the given letter. The letters are as follows for the new group; use lowercase letters for the old group:
  • F -- the first line number
  • L -- the last line number
  • N -- the number of lines = L-F+1
  • E -- F-1
  • M -- L+1.
%%
A literal %.
%c'C'
The single character, C.
%c'\OOO'
The character with the given octal code, OOO.
--line-format=LFMT
Use the given format to output all input lines in an if-then-else format.
--LTYPE-line-format=LFMT
Use the given format to output individual lines in an if-then-else format. LTYPE can be old, new, or unchanged. LFMT may contain:
%L
Contents of the line.
%l
Contents of the line, excluding any trailing newline.
%[-][width][.[prec]]{doxX}n
Use the given printf-style specification for input line numbers.
%%
A literal %.
%c'C'
The single character, C.
%c'\OOO'
The character with the given octal code, OOO.
-l
--paginate
Pass the output through pr to paginate it.
-t
--expand-tabs
Expand tabs into spaces in the output.
-T
--initial-tab
Make tabs line up by prepending a tab.
-r
--recursive
Recursively compare any subdirectories found.
-N
--new-file
Treat absent files as being empty.
--unidirectional-new-file
Treat absent first files as being empty.
-s
--report-identical-files
Report when two files are the same.
-x pattern
--exclude=pattern
Exclude files that match the given pattern.
-X file
--exclude-from=file
Exclude files that match any pattern in file.
-S file
--starting-file=file
Start with file when comparing directories.
--from-file=file1
Compare file1 to all operands. The file1 argument can also be the name of a directory.
--to-file=file2
Compare all operands to file2. The file2 argument can also be the name of a directory.
--horizon-lines=num
Keep num lines of the common prefix and suffix.
-d
--minimal
Try hard to find a smaller set of changes.
--speed-large-files
Assume large files and many scattered small changes.
-v
--version
Output version information.
--help
Display a help message.
file1, file2
Pathnames of the files to be compared. These can be in the following forms:

If you specify the --from-file or --to-file option, there are no restrictions on the files. If you specify a dash (-) instead of a filename, diff reads from standard input.

Description:

The diff utility reports the differences between two files.


Note: If you use diff to compare binary files, diff simply reports whether or not the files are different. If you want to see the differences between two binary files, use cmp.

For any two files, there may be several correct interpretations of the differences between them. The diff utility attempts to generate the smallest number of additions, changes, and deletions required to convert file1 into file2. No output is produced if the files are identical.


Note: This utility is subject to the GNU Public License (GPL). We've included it for use on development systems.

For detailed documentation about diff, see the GNU website at http://www.gnu.org/.

Exit status:

0
No differences were found.
1
Differences were found.
>1
An error occurred.

Contributing author:

GNU; report bugs to .

See also:

cksum, cmp, diff3, wc