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 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.
Report bugs to: bug-diffutils@gnu.org
GNU diffutils home page: <https://www.gnu.org/software/diffutils/>
General help using GNU software: <https://www.gnu.org/gethelp/>
The - for the first file says the line is not present in the second file. The + at the second file says the line is present in the second file but not in the first.
diff -c file1 file2
*** file1 2022-09-25 15:40:59.000000000 +0200
--- file2 2022-09-25 15:40:39.000000000 +0200
***************
*** 1,5 ****
192.168.1.1
- 192.168.1.2
192.168.1.3
192.168.1.4
192.168.1.5
--- 1,6 ----
192.168.1.1
192.168.1.3
192.168.1.4
192.168.1.5
+ 192.168.1.6
+
diff -u file1 file2
--- file1 2022-09-25 15:40:59.000000000 +0200
+++ file2 2022-09-25 15:40:39.000000000 +0200
@@ -1,5 +1,6 @@
192.168.1.1
-192.168.1.2
192.168.1.3
192.168.1.4
192.168.1.5
+192.168.1.6