DIFF(1) 							   User Commands							   DIFF(1)

NAME

       diff - compare files line by line

SYNOPSIS

       diff [OPTION]... FILES

DESCRIPTION

       Compare FILES line by line.

       Mandatory arguments to long options are mandatory for short options too.

       --normal
	      output a normal diff (the default)

       -q, --brief
	      report only when files differ

       -s, --report-identical-files
	      report when two files are the same

       -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

       -e, --ed
	      output an ed script

       -n, --rcs
	      output an RCS format diff

       -y, --side-by-side
	      output in two columns

       -W, --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

       -p, --show-c-function
	      show which C function each change is in

       -F, --show-function-line=RE
	      show the most recent line matching RE

       --label LABEL
	      use LABEL instead of file name (can be repeated)

       -t, --expand-tabs
	      expand tabs to spaces in output

       -T, --initial-tab
	      make tabs line up by prepending a tab

       --tabsize=NUM
	      tab stops every NUM (default 8) print columns

       --suppress-blank-empty
	      suppress space or tab before empty output lines

       -l, --paginate
	      pass output through `pr' to paginate it

       -r, --recursive
	      recursively compare any subdirectories found

       -N, --new-file
	      treat absent files as empty

       --unidirectional-new-file
	      treat absent first files as empty

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

       --no-ignore-file-name-case
	      consider case when comparing file names

       -x, --exclude=PAT
	      exclude files that match PAT

       -X, --exclude-from=FILE
	      exclude files that match any pattern in FILE

       -S, --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

       -i, --ignore-case
	      ignore case differences in file contents

       -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, --ignore-matching-lines=RE
	      ignore changes whose lines all match RE

       -a, --text
	      treat all files as text

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

       -D, --ifdef=NAME
	      output merged file with `#ifdef NAME' diffs

       --GTYPE-group-format=GFMT
	      format GTYPE input groups with GFMT

       --line-format=LFMT
	      format all input lines with LFMT

       --LTYPE-line-format=LFMT
	      format LTYPE input lines with LFMT

	      These format options provide fine-grained control over the output

	      of diff, generalizing -D/--ifdef.

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

	      GFMT (only) 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

       %(A=B?T:E)
	      if A equals B then T else E

	      LFMT (only) 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

	      Both GFMT and LFMT may contain:

       %%     %

       %c'C'  the single character C

       %c'OOO'
	      the character with octal code OOO

       C      the character C (other characters represent themselves)

       -d, --minimal
	      try hard to find a smaller set of changes

       --horizon-lines=NUM
	      keep NUM lines of the common prefix and suffix

       --speed-large-files
	      assume large files and many scattered small changes

       --help display this help and exit

       -v, --version
	      output version information and exit

       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 FILE(s).  If a FILE is `-', read standard input.  Exit status is 0 if inputs are the same, 1 if different, 2 if trouble.

AUTHOR

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

REPORTING BUGS

       Report bugs to: bug-diffutils@gnu.org
       GNU diffutils home page: <http://www.gnu.org/software/diffutils/>
       General help using GNU software: <http://www.gnu.org/gethelp/>

COPYRIGHT

       Copyright (C) 2011 Free Software Foundation, Inc.  License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>.
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to the extent permitted by law.

SEE ALSO

       wdiff(1), cmp(1), diff3(1), sdiff(1), patch(1)

       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 3.2							  September 2011							   DIFF(1)