.\" Generated by scdoc 1.11.4
.\" Complete documentation for this program is not available as a GNU info page
.ie \n(.g .ds Aq \(aq
.el       .ds Aq '
.nh
.ad l
.\" Begin generated content:
.TH "GENDIFF" "1" "2026-03-06" "RPM 6.0.1"
.PP
.SH NAME
gendiff - Utility to aid in error-free diff file generation
.PP
.SH SYNOPSIS
\fBgendiff\fR \fIDIRECTORY\fR \fIDIFF-EXTENSION\fR
.PP
.SH DESCRIPTION
\fBgendiff\fR is a tool for generating a \fIdiff\fR file from a single directory.\&
The generated \fIdiff\fR can be applied with the \fBpatch\fR(1) program to recreate
the changes.\&
.PP
\fBgendiff\fR looks for any files with \fIDIFF-EXTENSION\fR as their extension in the
specified \fIDIRECTORY\fR, and runs \fBdiff\fR(1) on the files with \fIDIFF-EXTENSION\fR and
the counterpart without it, in that order.\& This allows for generating diffs from
source code without making a full copy of the directory, which you'\&d otherwise
need when using the \fBdiff\fR(1) utility directly.\&
.PP
\fBgendiff\fR is commonly used to creating patches for the purposes of
packaging software with \fBrpmbuild\fR(1).\&
.PP
.SH ARGUMENTS
\fIDIRECTORY\fR
.RS 4
The directory to generate a diff from.\&
.PP
.RE
\fIDIFF-EXTENSION\fR
.RS 4
The diff extension to look for.\&
.PP
.RE
.SH EXIT STATUS
On success, 0 is returned, a nonzero failure code otherwise.\&
.PP
.SH EXAMPLES
Assuming you need to modify a source file called \fIsomefile.\&cpp\fR and
have chosen the extension \fIfix\fR, copy it to \fIsomefile.\&cpp.\&fix\fR before
editing it.\& Then edit the original file (\fIsomefile.\&cpp\fR).\&
.PP
After editing all the files you need to edit in this fashion, enter the
directory one level above where the source code resides, and run
\fBgendiff\fR on it:
.PP
.nf
.RS 4
gendiff myproject-1\&.0 \&.fix > myproject-1\&.0-fix\&.patch
.fi
.RE
.PP
.SH SEE ALSO
\fBdiff\fR(1), \fBpatch\fR(1)