FILTERDIFF(1) Man pages FILTERDIFF(1)

NAME


filterdiff - extract or exclude diffs from a diff file

SYNOPSIS


filterdiff [[-i PATTERN] | [--include=PATTERN]] [[-I FILE] |
[--include-from-file=FILE]] [[-p n] | [--strip-match=n]]
[--strip=n] [--git-prefixes=strip|keep]
[--addprefix=PREFIX] [--addoldprefix=PREFIX]
[--addnewprefix=PREFIX] [[-x PATTERN] |
[--exclude=PATTERN]] [[-X FILE] |
[--exclude-from-file=FILE]] [[-v] | [--verbose]] [--clean]
[--in-place] [[-z] | [--decompress]] [[-# RANGE] |
[--hunks=RANGE]] [--lines=RANGE] [[-FRANGE] |
[--files=RANGE]] [--annotate] [--format=FORMAT]
[--as-numbered-lines=WHEN] [--remove-timestamps] [file...]

filterdiff {[--help] | [--version] | [--list] | [--grep ...]}

DESCRIPTION


You can use filterdiff to obtain a patch that applies to files
matching the shell wildcard PATTERN from a larger collection of
patches. For example, to see the patches in patch-2.4.3.gz that apply
to all files called lp.c:

filterdiff -z -i '*/lp.c' patch-2.4.3.gz

If neither -i nor -x options are given, -i '*' is assumed. This way
filterdiff can be used to clean up an existing diff file, removing
redundant lines from the beginning (eg. the text from the mail body)
or between the chunks (eg. in CVS diffs). To extract pure patch data,
use a command like this:

filterdiff message-with-diff-in-the-body > patch

Filterdiff supports unified, context, and Git format diffs. Git
format includes support for binary files, file renames, permission
mode changes, and other Git-specific diff features.

Note that the interpretation of the shell wildcard pattern does not
count slash characters or periods as special (in other words, no
flags are given to fnmatch). This is so that "*/basename"-type
patterns can be given without limiting the number of pathname
components.

You can use both unified and context format diffs with this program.

OPTIONS


-iPATTERN, --include=PATTERN
Include only files matching PATTERN. All other lines in the input
are suppressed.

-IFILE, --include-from-file=FILE
Include only files matching any pattern listed in FILE, one
pattern per line. All other lines in the input are suppressed.

-xPATTERN, --exclude=PATTERN
Exclude files matching PATTERN. All other lines in the input are
displayed.

-XFILE, --exclude-from-file=FILE
Exclude files matching any pattern listed in FILE, one pattern
per line. All other lines in the input are displayed.

-pn, --strip-match=n
When matching, ignore the first n components of the pathname.

-#RANGE, --hunks=RANGE
Only include hunks within the specified RANGE. Hunks are numbered
from 1, and the range is a comma-separated list of numbers or
"first-last" spans, optionally preceded by a modifier 'x' which
inverts the entire range; either the first or the last in the
span may be omitted to indicate no limit in that direction.

--lines=RANGE
Only include hunks that contain lines from the original file that
lie within the specified RANGE. Lines are numbered from 1, and
the range is a comma-separated list of numbers or "first-last"
spans, optionally preceded by a modifier 'x' which inverts the
entire range; either the first or the last in the span may be
omitted to indicate no limit in that direction.

-F=RANGE, --files=RANGE
Only include files indicated by the specified RANGE. Files are
numbered from 1 in the order they appear in the patch input, and
the range is a comma-separated list of numbers or "first-last"
spans, optionally preceded by a modifier 'x' which inverts the
entire range; either the first or the last in the span may be
omitted to indicate no limit in that direction.

--annotate
Annotate each hunk with the filename and hunk number.

--format=unified|context
Use specified output format.

--strip=n
Remove the first n components of pathnames in the output.

--git-prefixes=strip|keep
How to handle a/ and b/ prefixes in Git diff filenames. With
strip, removes the prefixes both for filename matching (when
using -i and -x options) and for filename output (similar to
--strip). With keep (default), preserves existing behavior.
Applies to both Git-specific diffs (binary files, renames, mode
changes) and traditional diffs when part of a Git patch. Note:
With keep, copy and rename operations are treated as if they had
a/ and b/ prefixes for consistency with other Git operations. The
default will change to strip in version 0.5.0.

--addprefix=PREFIX
Prefix pathnames in the output by PREFIX. This will override any
individual settings specified with the --addoldprefix or
--addnewprefix options.

--addoldprefix=PREFIX
Prefix pathnames for old or original files in the output by
PREFIX.

--addnewprefix=PREFIX
Prefix pathnames for updated or new files in the output by
PREFIX.

--as-numbered-lines=before|after|original-before|original-after
Instead of a patch fragment, display the lines of the selected
hunks with the line number of the file before (or after) the
patch is applied, followed by a TAB character and a colon, at the
beginning of each line. Each hunk except the first will have a
line consisting of "..." before it.

The before and after options show line numbers adjusted for any
skipped hunks. The original-before and original-after options
show line numbers as they appear in the original diff, preserving
the original line number context. This is useful for CI/CD
systems that need to report errors on the exact line numbers from
the original diff.

--remove-timestamps
Do not include file timestamps in the output.

-v, --verbose
Always show non-diff lines in the output. By default, non-diff
lines are only shown when excluding a filename pattern.

--clean
Always remove all non-diff lines from the output. Even when
excluding a filename pattern.

--in-place
Write output to the original input files instead of standard
output. This allows filtering multiple patch files without manual
redirection loops.

-z, --decompress
Decompress files with extensions .gz and .bz2.

--help
Display a short usage message.

--version
Display the version number of filterdiff.

--list
Behave like lsdiff(1) instead.

--grep
Behave like grepdiff(1) instead.

EXAMPLES


To see all patch hunks that affect the first five lines of a C file:

filterdiff -i '*.c' --lines=-5 < patch

To see the first hunk of each file patch, use:

filterdiff -#1 patchfile

To see patches modifying a ChangeLog file in a subdirectory, use:

filterdiff -p1 Changelog

To see the complete patches for each patch that modifies line 1 of
the original file, use:

filterdiff --lines=1 patchfile | lsdiff | \
xargs -rn1 filterdiff patchfile -i

To see all but the first hunk of a particular patch, you might use:

filterdiff -p1 -i file.c -#2- foo-patch

If you have a very specific list of hunks in a patch that you want to
see, list them:

filterdiff -#1,2,5-8,10,12,27-

To see the lines of the files that would be patched as they will
appear after the patch is applied, use:

filterdiff --as-numbered-lines=after patch.file

You can see the same context before the patch is applied with:

filterdiff --as-numbered-lines=before
patch.file

For CI/CD systems that need line numbers matching the original diff
context (useful for error reporting), use the original-* variants:

grepdiff pattern --output-matching=hunk \
--as-numbered-lines=original-after patch.file

Filterdiff can also be used to convert between unified and context
format diffs:

filterdiff -v --format=unified context.diff

Git format diffs are fully supported, including binary files, file
renames, and permission mode changes. For example, to extract only
the renames from a git diff:

# With --git-prefixes=strip (matches bare filename)
filterdiff --git-prefixes=strip -i '*/newname' git-patch-with-renames.patch

# With --git-prefixes=keep (default, matches with b/ prefix)
filterdiff -i 'b/*/newname' git-patch-with-renames.patch

SEE ALSO


lsdiff(1), grepdiff(1), patchview(1)

AUTHOR


Tim Waugh <twaugh@redhat.com>
Package maintainer

patchutils 23 Jan 2009 FILTERDIFF(1)