Usage: diff [OPTION]... FILES
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 and timestamp (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 --no-dereference don't follow symbolic links
-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
-Z, --ignore-trailing-space ignore white space at line end
-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 where lines are all blank
-I, --ignore-matching-lines=RE ignore changes where all lines 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 --color[=WHEN] colorize the output; WHEN can be 'never', 'always', or 'auto' (the default) --palette=PALETTE specify the colors to use when --color is active PALETTE is a colon-separated list terminfo capabilities --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. 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/>