Back up the original file.

When not backing up all original files, these options control whether a backup should be made when a patch does not match the original file. The default is to make backups unless --posix is specified.

Interpret patchfile as a context diff.

cd to directory before beginning patch operations.

Print results of applying a patch, but don't change any files.

Treat the contents of patchfile as ed commands.

Force all changes, even those that look incorrect. Skip patches if the original file does not exist; force patches for files with the wrong version specified; assume patches are never reversed.

Specify whether to check the original file out of source control if it is missing or read-only. If num is a positive number, get the file. If it is negative, prompt the user. If it is 0, do not check files out of source control. The default is negative or the value of the PATCH_GET environment variable when set, unless the --posix option is given. In that case, the default is 0.

Print help message, then exit.

Read patch from file instead of stdin.

Ignore whitespace while pattern matching.

Interpret patch file as a normal diff.

Print output to file.

Specify how much of preceding pathname to strip. A num of 0 strips everything, leaving just the filename. 1 strips the leading /. Each higher number after that strips another directory from the left.

Set the quoting style used when printing names. The default style is shell, unless set by the environment variable QUOTING_STYLE. style may be one of the following:

c

Quote as a C language string.

escape

Like c, but without surrounding double-quote characters.

literal

Print without quoting.

shell

Quote for use in shell when needed.

shell-always

Quote for use in shell even if not needed.

Conform more strictly to the POSIX standard.

Place rejects (hunks of the patch file that patch fails to place within the original file) in file. Default is original.rej.

Suppress commentary.

Skip patches if the original file does not exist.

Interpret patch file as a unified context diff.

Verbose mode.

Print version number and exit.

Back up the original file in original.suffix.

Prepend prefix to the backup filename.

Mark all changes with:

#ifdef string #endif

If patch creates any empty files, delete them.

Specify the maximum number of lines that may be ignored (fuzzed over) when deciding where to install a hunk of code. The default is 2. Meaningful only with context diffs.

Ignore patches that appear to be reversed or to have already been applied.

Do a reverse patch: attempt to undo the damage done by patching with the old and new files reversed.

When original file timestamps match the times given in the patch header, set timestamps for patched files according to the context diff headers. Use option -f to force date changes. Assume timestamps are in local time.

Specify method for creating backup files (overridden by -B):

t, numbered

Make numbered backups.

nil, existing

Back up files according to preexisting backup schemes, with simple backups as the default. This is patch's default behavior.

never, simple

Make simple backups.

Use the specified prefix with a file's basename to create backup filenames. Useful for specifying a directory.

When original file timestamps match the times given in the patch header, set timestamps for patched files according to the context diff headers. Use option -f to force date changes. Assume timestamps are in Coordinated Universal Time (UTC).

Specify the directory for temporary files; /tmp by default.

Suffix to append to backup files instead of .orig or ~.

Specify how output should be quoted (see --quoting-style).

Specify whether patch should retrieve missing or read-only files from source control (see -g).

When set, patch conforms more strictly to the POSIX standard (see --posix).

Specify what method to use in naming backups (see -V).