Originální popis anglicky:
patch - apply changes to files
Návod, kniha: POSIX Programmer's Manual
patch [-blNR][ -c| -e| -n][-d
dir][-D define][-i
patchfile]
[-o
outfile][-p
num][-r
rejectfile
][file]
The
patch utility shall read a source (patch) file containing any of the
three forms of difference (diff) listings produced by the
diff utility
(normal, context, or in the style of
ed) and apply those differences to
a file. By default,
patch shall read from the standard input.
The
patch utility shall attempt to determine the type of the
diff
listing, unless overruled by a
-c,
-e, or
-n option.
If the patch file contains more than one patch,
patch shall attempt to
apply each of them as if they came from separate patch files. (In this case,
the application shall ensure that the name of the patch file is determinable
for each
diff listing.)
The
patch utility shall conform to the Base Definitions volume of
IEEE Std 1003.1-2001, Section 12.2, Utility Syntax Guidelines.
The following options shall be supported:
- -b
- Save a copy of the original contents of each modified file,
before the differences are applied, in a file of the same name with the
suffix .orig appended to it. If the file already exists, it shall
be overwritten; if multiple patches are applied to the same file, the
.orig file shall be written only for the first patch. When the
-o outfile option is also specified, file
.orig shall not be created but, if outfile already exists,
outfile .orig shall be created.
- -c
- Interpret the patch file as a context difference (the
output of the utility diff when the -c or -C options
are specified).
- -d dir
- Change the current directory to dir before
processing as described in the EXTENDED DESCRIPTION section.
- -D define
- Mark changes with one of the following C preprocessor
constructs:
#ifdef define
...
#endif
#ifndef define
...
#endif
optionally combined with the C preprocessor construct
#else. If the
patched file is processed with the C preprocessor, where the macro
define is defined, the output shall contain the changes from the patch
file; otherwise, the output shall not contain the patches specified in the
patch file.
- -e
- Interpret the patch file as an ed script, rather
than a diff script.
- -i patchfile
- Read the patch information from the file named by the
pathname patchfile, rather than the standard input.
- -l
- (The letter ell.) Cause any sequence of <blank>s in
the difference script to match any sequence of <blank>s in the input
file. Other characters shall be matched exactly.
- -n
- Interpret the script as a normal difference.
- -N
- Ignore patches where the differences have already been
applied to the file; by default, already-applied patches shall be
rejected.
- -o outfile
- Instead of modifying the files (specified by the
file operand or the difference listings) directly, write a copy of
the file referenced by each patch, with the appropriate differences
applied, to outfile. Multiple patches for a single file shall be
applied to the intermediate versions of the file created by any previous
patches, and shall result in multiple, concatenated versions of the file
being written to outfile.
- -p num
- For all pathnames in the patch file that indicate the names
of files to be patched, delete num pathname components from the
beginning of each pathname. If the pathname in the patch file is absolute,
any leading slashes shall be considered the first component (that is,
-p 1 shall remove the leading slashes). Specifying
-p 0 shall cause the full pathname to be used. If -p
is not specified, only the basename (the final pathname component) shall
be used.
- -R
- Reverse the sense of the patch script; that is, assume that
the difference script was created from the new version to the old version.
The -R option cannot be used with ed scripts. The
patch utility shall attempt to reverse each portion of the script
before applying it. Rejected differences shall be saved in swapped format.
If this option is not specified, and until a portion of the patch file is
successfully applied, patch attempts to apply each portion in its
reversed sense as well as in its normal sense. If the attempt is
successful, the user shall be prompted to determine whether the -R
option should be set.
- -r rejectfile
- Override the default reject filename. In the default case,
the reject file shall have the same name as the output file, with the
suffix .rej appended to it; see Patch Application .
The following operand shall be supported:
- file
- A pathname of a file to patch.
See the INPUT FILES section.
Input files shall be text files.
The following environment variables shall affect the execution of
patch:
- LANG
- Provide a default value for the internationalization
variables that are unset or null. (See the Base Definitions volume of
IEEE Std 1003.1-2001, Section 8.2, Internationalization
Variables for the precedence of internationalization variables used to
determine the values of locale categories.)
- LC_ALL
- If set to a non-empty string value, override the values of
all the other internationalization variables.
- LC_CTYPE
- Determine the locale for the interpretation of sequences of
bytes of text data as characters (for example, single-byte as opposed to
multi-byte characters in arguments and input files).
- LC_MESSAGES
- Determine the locale that should be used to affect the
format and contents of diagnostic messages written to standard error and
informative messages written to standard output.
- NLSPATH
- Determine the location of message catalogs for the
processing of LC_MESSAGES .
- LC_TIME
- Determine the locale for recognizing the format of file
timestamps written by the diff utility in a context-difference
input file.
Default.
Not used.
The standard error shall be used for diagnostic and informational messages.
The output of the
patch utility, the save files (
.orig suffixes),
and the reject files (
.rej suffixes) shall be text files.
A patch file may contain patching instructions for more than one file; filenames
shall be determined as specified in Filename Determination . When the
-b option is specified, for each patched file, the original shall be
saved in a file of the same name with the suffix
.orig appended to it.
For each patched file, a reject file may also be created as noted in Patch
Application . In the absence of a
-r option, the name of this file
shall be formed by appending the suffix
.rej to the original filename.
The patch file shall contain zero or more lines of header information followed
by one or more patches. Each patch shall contain zero or more lines of
filename identification in the format produced by
diff -c, and
one or more sets of
diff output, which are customarily called
hunks.
The
patch utility shall recognize the following expression in the header
information:
- Index: pathname
-
The file to be patched is named pathname.
If all lines (including headers) within a patch begin with the same leading
sequence of <blank>s, the
patch utility shall remove this
sequence before proceeding. Within each patch, if the type of difference is
context, the
patch utility shall recognize the following expressions:
- *** filename timestamp
-
The patches arose from filename.
- --- filename timestamp
-
The patches should be applied to filename.
Each hunk within a patch shall be the
diff output to change a line range
within the original file. The line numbers for successive hunks within a patch
shall occur in ascending order.
If no
file operand is specified,
patch shall perform the following
steps to determine the filename to use:
- 1.
- If the type of diff is context, the patch
utility shall delete pathname components (as specified by the -p
option) from the filename on the line beginning with
"***" , then test for the existence of this file relative
to the current directory (or the directory specified with the -d
option). If the file exists, the patch utility shall use this
filename.
- 2.
- If the type of diff is context, the patch
utility shall delete the pathname components (as specified by the
-p option) from the filename on the line beginning with
"---" , then test for the existence of this file relative
to the current directory (or the directory specified with the -d
option). If the file exists, the patch utility shall use this
filename.
- 3.
- If the header information contains a line beginning with
the string Index:, the patch utility shall delete pathname
components (as specified by the -p option) from this line, then
test for the existence of this file relative to the current directory (or
the directory specified with the -d option). If the file exists,
the patch utility shall use this filename.
- 4.
- If an SCCS directory exists in the current
directory, patch shall attempt to perform a get -e
SCCS/s. filename command to retrieve an editable version of
the file. If the file exists, the patch utility shall use this
filename.
- 5.
- The patch utility shall write a prompt to standard
output and request a filename interactively from the controlling terminal
(for example, /dev/tty).
If the
-c,
-e, or
-n option is present, the
patch
utility shall interpret information within each hunk as a context difference,
an
ed difference, or a normal difference, respectively. In the absence
of any of these options, the
patch utility shall determine the type of
difference based on the format of information within the hunk.
For each hunk, the
patch utility shall begin to search for the place to
apply the patch at the line number at the beginning of the hunk, plus or minus
any offset used in applying the previous hunk. If lines matching the hunk
context are not found,
patch shall scan both forwards and backwards at
least 1000 bytes for a set of lines that match the hunk context.
If no such place is found and it is a context difference, then another scan
shall take place, ignoring the first and last line of context. If that fails,
the first two and last two lines of context shall be ignored and another scan
shall be made. Implementations may search more extensively for installation
locations.
If no location can be found, the
patch utility shall append the hunk to
the reject file. The rejected hunk shall be written in context-difference
format regardless of the format of the patch file. If the input was a normal
or
ed-style difference, the reject file may contain differences with
zero lines of context. The line numbers on the hunks in the reject file may be
different from the line numbers in the patch file since they shall reflect the
approximate locations for the failed hunks in the new file rather than the old
one.
If the type of patch is an
ed diff, the implementation may accomplish the
patching by invoking the
ed utility.
The following exit values shall be returned:
- 0
- Successful completion.
- 1
- One or more lines were written to a reject file.
- >1
- An error occurred.
Patches that cannot be correctly placed in the file shall be written to a reject
file.
The following sections are informative.
The
-R option does not work with
ed scripts because there is too
little information to reconstruct the reverse operation.
The
-p option makes it possible to customize a patch file to local user
directory structures without manually editing the patch file. For example, if
the filename in the patch file was:
/curds/whey/src/blurfl/blurfl.c
Setting
-p 0 gives the entire pathname unmodified;
-p 1 gives:
curds/whey/src/blurfl/blurfl.c
without the leading slash,
-p 4 gives:
and not specifying
-p at all gives:
None.
Some of the functionality in historical
patch implementations was not
specified. The following documents those features present in historical
implementations that have not been specified.
A deleted piece of functionality was the
'+' pseudo-option allowing an
additional set of options and a patch file operand to be given. This was seen
as being insufficiently useful to standardize.
In historical implementations, if the string
"Prereq:" appeared
in the header, the
patch utility would search for the corresponding
version information (the string specified in the header, delimited by
<blank>s or the beginning or end of a line or the file) anywhere in the
original file. This was deleted as too simplistic and insufficiently
trustworthy a mechanism to standardize. For example, if:
were in the header, the presence of a delimited 1.2 anywhere in the file would
satisfy the prerequisite.
The following options were dropped from historical implementations of
patch as insufficiently useful to standardize:
- -b
- The -b option historically provided a method for
changing the name extension of the backup file from the default
.orig. This option has been modified and retained in this volume of
IEEE Std 1003.1-2001.
- -F
- The -F option specified the number of lines of a
context diff to ignore when searching for a place to install a patch.
- -f
- The -f option historically caused patch not
to request additional information from the user.
- -r
- The -r option historically provided a method of
overriding the extension of the reject file from the default
.rej.
- -s
- The -s option historically caused patch to
work silently unless an error occurred.
- -x
- The -x option historically set internal debugging
flags.
In some file system implementations, the saving of a
.orig file may
produce unwanted results. In the case of 12, 13, or 14-character filenames (on
file systems supporting 14-character maximum filenames), the
.orig file
overwrites the new file. The reject file may also exceed this filename limit.
It was suggested, due to some historical practice, that a tilde (
'~' )
suffix be used instead of
.orig and some other character instead of the
.rej suffix. This was rejected because it is not obvious to the user
which file is which. The suffixes
.orig and
.rej are clearer and
more understandable.
The
-b option has the opposite sense in some historical
implementations-do not save the
.orig file. The default case here is
not to save the files, making
patch behave more consistently with the
other standard utilities.
The
-w option in early proposals was changed to
-l to match
historical practice.
The
-N option was included because without it, a non-interactive
application cannot reject previously applied patches. For example, if a user
is piping the output of
diff into the
patch utility, and the
user only wants to patch a file to a newer version non-interactively, the
-N option is required.
Changes to the
-l option description were proposed to allow matching
across <newline>s in addition to just <blank>s. Since this is not
historical practice, and since some ambiguities could result, it is suggested
that future developments in this area utilize another option letter, such as
-L.
None.
ed ,
diff
Portions of this text are reprinted and reproduced in electronic form from IEEE
Std 1003.1, 2003 Edition, Standard for Information Technology -- Portable
Operating System Interface (POSIX), The Open Group Base Specifications Issue
6, Copyright (C) 2001-2003 by the Institute of Electrical and Electronics
Engineers, Inc and The Open Group. In the event of any discrepancy between
this version and the original IEEE and The Open Group Standard, the original
IEEE and The Open Group Standard is the referee document. The original
Standard can be obtained online at http://www.opengroup.org/unix/online.html
.
