DIFF(1) 							   User Commands							   DIFF(1)

NAME

       diff - compare files line by line

SYNOPSIS

       diff [OPTION]... FILES

DESCRIPTION

       Compare files line by line.

       -i  --ignore-case
	      Ignore case differences in file contents.

       --ignore-file-name-case
	      Ignore case when comparing file names.

       --no-ignore-file-name-case
	      Consider case when comparing file names.

       -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 RE.

       --strip-trailing-cr
	      Strip trailing carriage return on input.

       -a  --text
	      Treat all files as text.

       -c  -C NUM  --context[=NUM]
	      Output NUM (default 3) lines of copied context.

       -u  -U NUM  --unified[=NUM]
	      Output NUM (default 3) lines of unified context.

       --label LABEL
	      Use LABEL instead of file name.

       -p  --show-c-function
	      Show which C function each change is in.

       -F RE  --show-function-line=RE
	      Show the most recent line matching RE.

       -q  --brief
	      Output only whether files differ.

       -e  --ed
	      Output an ed script.

       --normal
	      Output a normal diff.

       -n  --rcs
	      Output an RCS format diff.

       -y  --side-by-side
	      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
	      Do not output common lines.

       -D NAME	--ifdef=NAME
	      Output merged file to show `#ifdef NAME' diffs.

       --GTYPE-group-format=GFMT
	      Similar, but format GTYPE input groups with GFMT.

       --line-format=LFMT
	      Similar, but format all input lines with LFMT.

       --LTYPE-line-format=LFMT
	      Similar, but format LTYPE input lines with LFMT.

       LTYPE is `old', `new', or `unchanged'.
	      GTYPE is LTYPE or `changed'.

	      GFMT may contain:

       %<     lines from FILE1

       %>     lines from FILE2

       %=     lines common to FILE1 and FILE2

       %[-][WIDTH][.[PREC]]{doxX}LETTER
	      printf-style spec for LETTER

	      LETTERs are as follows for new group, lower case for old group:

       F      first line number

       L      last line number

       N      number of lines = L-F+1

       E      F-1

       M      L+1

	      LFMT may contain:

       %L     contents of line

       %l     contents of line, excluding any trailing newline

       %[-][WIDTH][.[PREC]]{doxX}n
	      printf-style spec for input line number

	      Either GFMT or LFMT may contain:

       %%     %

       %c'C'  the single character C

       %c'OOO'
	      the character with octal code OOO

       -l  --paginate
	      Pass the output through `pr' to paginate it.

       -t  --expand-tabs
	      Expand tabs to spaces in 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 empty.

       --unidirectional-new-file
	      Treat absent first files as empty.

       -s  --report-identical-files
	      Report when two files are the same.

       -x PAT  --exclude=PAT
	      Exclude files that match PAT.

       -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.  FILE1 can be a directory.

       --to-file=FILE2
	      Compare all operands to FILE2.  FILE2 can be 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 info.

       --help Output this help.

       FILES  are `FILE1 FILE2' or `DIR1 DIR2' or `DIR FILE...' or `FILE... DIR'.  If --from-file or --to-file is given, there are no restrictions
       on FILES.  If a FILE is `-', read standard input.

AUTHOR

       Written by Paul Eggert, Mike Haertel, David Hayes, Richard Stallman, and Len Tower.

REPORTING BUGS

       Report bugs to <bug-gnu-utils@gnu.org>.

COPYRIGHT

       Copyright (C) 2002 Free Software Foundation, Inc.

       This program comes with NO WARRANTY, to the extent permitted by law.  You may redistribute copies of this program under the  terms  of  the
       GNU General Public License.  For more information about these matters, see the file named COPYING.

SEE ALSO

       The  full documentation for diff is maintained as a Texinfo manual.  If the info and diff programs are properly installed at your site, the
       command

	      info diff

       should give you access to the complete manual.

diffutils 2.8.1 						    April 2002								   DIFF(1)