N Days to learn the diff of a Linux command

Use

Compare file differences by row, or you can compare directories

Usage

diff [OPTION]... FILES

Common options

-I.--ignore-case
Ignore case

--ignore-file-name-case
Ignore file name capitalization

--no-ignore-file-name-case
File names are case sensitive

-E--ignore-tab-expansion
Ignore tab characters

-B--ignore-space-change
Ignore spaces

-W--ignore-all-space
Ignore All spaces

-B--ignore-blank-lines
Ignore blank lines

-I RE--ignore-matching-lines=re
Filter rows that match

--strip-trailing-cr
Remove end of line carriage return character

-A--text
All file contents 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 the file where the difference line is located

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

-Q--brief
Whether the direct output results are different

-E--ed
(Output an ED script.)

--normal
(Output a normal diff.)

-N--rcs
(Output an RCS format diff.)

-Y--side-by-side
Output 2 files at the same time, control display

-W NUM--width=num
(Output at the most NUM (default) print columns.)

--left-column
Left output full content, right only output difference

--suppress-common-lines
Output only differential rows

-D NAME--ifdef=name
(Output merged file to show ' #ifdef NAME ' diffs.)

--gtype-group-format=gfmt
(Similar, but format GTYPE input groups with GFMT.)
(GTYPE is LTYPE or ' changed '.)

--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 ')

-L--paginate
Pagination Display

-T--expand-tabs
tab character changed to space when 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 both files are the same.)

-X PAT--exclude=pat
(Exclude files that match PAT.)

-X FILE--exclude-from=file
(Exclude files, 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 Program Version information

--help
Display Help information

Practice

1 Comparison of 2 files

# 显示所有diff -y dir1/friend.php friend.php# 只显示差异diff -y --suppress-common-lines dir1/friend.php friend.php# 只显示左边完整内容，右边只显示差异内容diff -y --left-column dir1/friend.php friend.php

Wipe reference

"1" Man diff

N Days to learn the diff of a Linux command