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)
