GREPDIFF(1)

NAME
grepdiff - show files modified by a diff containing a regex

SYNOPSIS

grepdiff [[-n] | [--line-number]] [[-N] | [--number-files]] [[-p n] | [--strip-match=n]] [--strip=n] [--git-prefixes=strip|keep] [--git-extended-diffs=exclude|include] [--addprefix=PREFIX] [--addoldprefix=PREFIX] [--addnewprefix=PREFIX] [[-s] | [--status]] [--empty-files-as-absent] [[-i PATTERN] | [--include=PATTERN]] [[-I FILE] | [--include-from-file=FILE]] [[-x PATTERN] | [--exclude=PATTERN]] [[-X FILE] | [--exclude-from-file=FILE]] [[-# RANGE] | [--hunks=RANGE]] [--lines=RANGE] [[-FRANGE] | [--files=RANGE]] [--annotate] [--as-numbered-lines=WHEN] [--format=FORMAT] [--remove-timestamps] [[-v] | [--verbose]] [[-z] | [--decompress]] [[-E] | [--extended-regexp]] [[-H] | [--with-filename]] [[-h] | [--no-filename]] [--output-matching=WHAT] [--only-match=WHAT] {[REGEX] | [-f FILE]} [file...]

grepdiff {[--help] | [--version] | [--list] | [--filter ...]}

DESCRIPTION

For each file modified by a patch, if the patch hunk contains the REGEX then the file's name is printed.

The regular expression is treated as POSIX Basic Regular Expression syntax, unless the -E option is given in which case POSIX Extended Regular Expression syntax is used. When compiled with PCRE2 support, PCRE regular expressions are used instead of POSIX regular expressions, and the -E option has no effect since PCRE already supports extended regular expression features by default.

You can use unified, context, and Git format diffs with this program. Git format includes support for binary files, file renames, permission mode changes, and other Git-specific diff features.

OPTIONS

-n, --line-number
    Display the line number that each patch begins at. If verbose output is requested, each matching hunk is listed as well.

    For a description of the output format see lsdiff(1).

-N, --number-files
    File numbers are listed, beginning at 1, before each filename.

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

--strip=n
    Remove the first n components of the pathname before displaying it.

--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.

--git-extended-diffs=exclude|include
    Controls whether to process Git diffs without traditional content hunks. This includes renames, copies, mode-only changes, and binary files. With exclude (default in 0.4.x), these diffs are skipped. With include (default in 0.5.0+), these diffs are processed normally. This option affects file numbering with -N and file filtering with -F.

--addprefix=PREFIX
    Prefix the pathname with PREFIX before displaying it. 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.

-s
    Show file additions, modifications and removals. A file addition is indicated by a “+”, a removal by a “-”, and a modification by a “!”.

--empty-files-as-absent
    Treat empty files as absent when matching patterns.

-iPATTERN, --include=PATTERN
    Include only files matching PATTERN.

-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.

-x PATTERN --exclude=PATTERN
    Exclude files matching PATTERN.

-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.

-#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 list 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 list 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.

--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.

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

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

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

-E, --extended-regexp
    Use POSIX Extended Regular Expression syntax. Note: when compiled with PCRE2 support, this option has no effect as PCRE regular expressions are used by default and already support extended regular expression features.

-H, --with-filename
    Print the name of the patch file containing each match.

-h, --no-filename
    Suppress the name of the patch file containing each match.

-fFILE, --file=FILE
    Read regular expressions from FILE, one per line.

--output-matching=hunk|file
    Display the matching hunk-level or file-level diffs.

--only-match=rem|removals|add|additions|mod|modifications|all
    Limit regex matching to removals, additions, modifications or the whole hunk.

--help
    Display a short usage message.

--version
    Display the version number of grepdiff.

--filter
    Behave like filterdiff(1) instead.

--list
    Behave like lsdiff(1) instead.

EXAMPLES

To quickly identify which files in a large patch contain memory allocation changes (useful for code review):

    grepdiff "malloc\|free\|realloc" large-patch.diff

This shows only the filenames, giving you a quick overview without being overwhelmed by diff content.

To see the actual hunks containing the pattern:

    grepdiff --output-matching=hunk "malloc" patch.diff

To see complete file diffs for files containing the pattern:

    grepdiff --output-matching=file "malloc" patch.diff

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

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

Git format diffs are fully supported. For example, to find files in a git patch that contain changes to malloc calls:

    grepdiff "malloc" git-patch.patch

Note that grepdiff searches in the hunk content (the actual code changes), not in Git metadata like rename headers. Files with only renames or mode changes (no content hunks) won't be found even if the pattern appears in the Git headers.

SEE ALSO

filterdiff(1), lsdiff(1), patchview(1)

AUTHOR

Tim Waugh <twaugh@redhat.com>
    Package maintainer