--- name: "diff" section: "1" platform: "linux" package: "diffutils" version: "3.12-2" release: "Arch Linux 2026-11-01" platforms: ["linux", "freebsd", "openbsd", "macos"] url: "https://new.carta.tech/diff" --- # diff(1) compare files line by line ## 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 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**\[=*WHEN*\] color output; WHEN is 'never', 'always', or 'auto'; plain **--color** means **--color=**'auto' - **--palette**=*PALETTE* the colors to use when **--color** is active; PALETTE is a colon-separated list of 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. ## 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: \\ General help using GNU software: \ ## COPYRIGHT Copyright © 2025 Free Software Foundation, Inc. License GPLv3+: GNU GPL version 3 or later \.\ 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)](/wdiff/1.md), [**cmp**(1)](/cmp/1.md), [**diff3**(1)](/diff3/1.md), [**sdiff**(1)](/sdiff/1.md), [**patch**(1)](/patch/1.md) 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.