功能說明：修補文件。

語法：patch[-bceEflnNRstTuvZ][-B<備份字首字符串>][-d<工作目錄>][-D<標示符號>][-F<監別列數>][-g<控制數值>][-i<修補文件>][-o<輸出文件>][-p<剝離層級>][-r<拒絕文件>][-V<備份方式>][-Y<備份字首字符串>][-z<備份字尾字符串>][--backup-if-mismatch][--binary][--help][--nobackup-if-mismatch][--verbose][原始文件<修補文件>]或path[-p<剝離層級>]<[修補文件]

補充說明：patch指令讓用戶利用設置修補文件的方式，修改，更新原始文件。倘若一次僅修改一個文件，可直接在指令列中下達指令依序執行。如果配合修補文件的方式則能一次修補大批文件，這也是Linux系統核心的升級方法之一。

參數：

-b或--backup備份每一個原始文件。

-B<備份字首字符串>或--prefix=<備份字首字符串>設置文件備份時，附加在文件名稱前面的字首字符串，該字符串可以是路徑名稱。

-c或--context把修補數據解譯成關聯性的差異。

-d<工作目錄>或--directory=<工作目錄>設置工作目錄。

-D<標示符號>或--ifdef=<標示符號>用指定的符號把改變的地方標示出來。

-e或--ed把修補數據解譯成ed指令可用的敘述文件。

-E或--remove-empty-files若修補過后輸出的文件其內容是一片空白，則移除該文件。

-f或--force此參數的效果和指定"-t"參數類似，但會假設修補數據的版本為新版本。

-F<監別列數>或--fuzz<監別列數>設置監別列數的最大值。

-g<控制數值>或--get=<控制數值>設置以RSC或SCCS控制修補作業。

-i<修補文件>或--input=<修補文件>讀取指定的修補問家你。

-l或--ignore-whitespace忽略修補數據與輸入數據的跳格，空格字符。

-n或--normal把修補數據解譯成一般性的差異。

-N或--forward忽略修補的數據較原始文件的版本更舊，或該版本的修補數據已使用過。

-o<輸出文件>或--output=<輸出文件>設置輸出文件的名稱，修補過的文件會以該名稱存放。

-p<剝離層級>或--strip=<剝離層級>設置欲剝離幾層路徑名稱。

-f<拒絕文件>或--reject-file=<拒絕文件>設置保存拒絕修補相關信息的文件名稱，預設的文件名稱為.rej。

-R或--reverse假設修補數據是由新舊文件交換位置而產生。

-s或--quiet或--silent不顯示指令執行過程，除非發生錯誤。

-t或--batch自動略過錯誤，不詢問任何問題。

-T或--set-time此參數的效果和指定"-Z"參數類似，但以本地時間為主。

-u或--unified把修補數據解譯成一致化的差異。

-v或--version顯示版本信息。

-V<備份方式>或--version-control=<備份方式>用"-b"參數備份目標文件后，備份文件的字尾會被加上一個備份字符串，這個字符串不僅可用"-z"參數變更，當使用"-V"參數指定不同備份方式時，也會產生不同字尾的備份字符串。

-Y<備份字首字符串>或--basename-prefix=--<備份字首字符串>設置文件備份時，附加在文件基本名稱開頭的字首字符串。

-z<備份字尾字符串>或--suffix=<備份字尾字符串>此參數的效果和指定"-B"參數類似，差別在于修補作業使用的路徑與文件名若為src/linux/fs/super.c，加上"backup/"字符串后，文件super.c會備份于/src/linux/fs/backup目錄里。

-Z或--set-utc把修補過的文件更改，存取時間設為UTC。

--backup-if-mismatch在修補數據不完全吻合，且沒有刻意指定要備份文件時，才備份文件。

--binary以二進制模式讀寫數據，而不通過標準輸出設備。

--help在線幫助。

--nobackup-if-mismatch在修補數據不完全吻合，且沒有刻意指定要備份文件時，不要備份文件。

--verbose詳細顯示指令的執行過程。

#p#

NAME

patch - apply a diff file to an original  

SYNOPSIS

patch [options] [originalfile [patchfile]]

but usually just

patch -pnum <patchfile  

DESCRIPTION

patch takes a patch file patchfile containing a difference listing produced by the diff program and applies those differences to one or more original files, producing patched versions. Normally the patched versions are put in place of the originals. Backups can be made; see the -b or --backup option. The names of the files to be patched are usually taken from the patch file, but if there's just one file to be patched it can specified on the command line as originalfile.

Upon startup, patch attempts to determine the type of the diff listing, unless overruled by a -c (--context), -e (--ed), -n (--normal), or -u (--unified) option. Context diffs (old-style, new-style, and unified) and normal diffs are applied by the patch program itself, while ed diffs are simply fed to the ed(1) editor via a pipe.

patch tries to skip any leading garbage, apply the diff, and then skip any trailing garbage. Thus you could feed an article or message containing a diff listing to patch, and it should work. If the entire diff is indented by a consistent amount, or if a context diff contains lines ending in CRLF or is encapsulated one or more times by prepending "- " to lines starting with "-" as specified by Internet RFC 934, this is taken into account.

With context diffs, and to a lesser extent with normal diffs, patch can detect when the line numbers mentioned in the patch are incorrect, and attempts to find the correct place to apply each hunk of the patch. As a first guess, it takes the line number mentioned for the hunk, plus or minus any offset used in applying the previous hunk. If that is not the correct place, patch scans both forwards and backwards for a set of lines matching the context given in the hunk. First patch looks for a place where all lines of the context match. If no such place is found, and it's a context diff, and the maximum fuzz factor is set to 1 or more, then another scan takes place ignoring the first and last line of context. If that fails, and the maximum fuzz factor is set to 2 or more, the first two and last two lines of context are ignored, and another scan is made. (The default maximum fuzz factor is 2.) If patch cannot find a place to install that hunk of the patch, it puts the hunk out to a reject file, which normally is the name of the output file plus a .rej suffix, or # if .rej would generate a file name that is too long (if even appending the single character # makes the file name too long, then # replaces the file name's last character). (The rejected hunk comes out in ordinary context diff form regardless of the input patch's form. If the input was a normal diff, many of the contexts are simply null.) The line numbers on the hunks in the reject file may be different than in the patch file: they reflect the approximate location patch thinks the failed hunks belong in the new file rather than the old one.

As each hunk is completed, you are told if the hunk failed, and if so which line (in the new file) patch thought the hunk should go on. If the hunk is installed at a different line from the line number specified in the diff you are told the offset. A single large offset may indicate that a hunk was installed in the wrong place. You are also told if a fuzz factor was used to make the match, in which case you should also be slightly suspicious. If the --verbose option is given, you are also told about hunks that match exactly.

If no original file origfile is specified on the command line, patch tries to figure out from the leading garbage what the name of the file to edit is, using the following rules.

First, patch takes an ordered list of candidate file names as follows:

*

If the header is that of a context diff, patch takes the old and new file names in the header. A name is ignored if it does not have enough slashes to satisfy the -pnum or --strip=num option. The name /dev/null is also ignored.

*

If there is an Index: line in the leading garbage and if either the old and new names are both absent or if patch is conforming to POSIX, patch takes the name in the Index: line.

*

For the purpose of the following rules, the candidate file names are considered to be in the order (old, new, index), regardless of the order that they appear in the header.

Then patch selects a file name from the candidate list as follows:

*

If some of the named files exist, patch selects the first name if conforming to POSIX, and the best name otherwise.

*

If patch is not ignoring RCS, ClearCase, and SCCS (see the -g num or --get=num option), and no named files exist but an RCS, ClearCase, or SCCS master is found, patch selects the first named file with an RCS, ClearCase, or SCCS master.

*

If no named files exist, no RCS, ClearCase, or SCCS master was found, some names are given, patch is not conforming to POSIX, and the patch appears to create a file, patch selects the best name requiring the creation of the fewest directories.

*

If no file name results from the above heuristics, you are asked for the name of the file to patch, and patch selects that name.

To determine the best of a nonempty list of file names, patch first takes all the names with the fewest path name components; of those, it then takes all the names with the shortest basename; of those, it then takes all the shortest names; finally, it takes the first remaining name.

Additionally, if the leading garbage contains a Prereq: line, patch takes the first word from the prerequisites line (normally a version number) and checks the original file to see if that word can be found. If not, patch asks for confirmation before proceeding.

The upshot of all this is that you should be able to say, while in a news interface, something like the following:

| patch -d /usr/src/local/blurfl
 

and patch a file in the blurfl directory directly from the article containing the patch.

If the patch file contains more than one patch, patch tries to apply each of them as if they came from separate patch files. This means, among other things, that it is assumed that the name of the file to patch must be determined for each diff listing, and that the garbage before each diff listing contains interesting things such as file names and revision level, as mentioned previously.  

OPTIONS

-b or --backup

Make backup files. That is, when patching a file, rename or copy the original instead of removing it. When backing up a file that does not exist, an empty, unreadable backup file is created as a placeholder to represent the nonexistent file. See the -V or --version-control option for details about how backup file names are determined.

--backup-if-mismatch

Back up a file if the patch does not match the file exactly and if backups are not otherwise requested. This is the default unless patch is conforming to POSIX.

--no-backup-if-mismatch

Do not back up a file if the patch does not match the file exactly and if backups are not otherwise requested. This is the default if patch is conforming to POSIX.

-B pref or --prefix=pref

Prefix pref to a file name when generating its simple backup file name. For example, with -B /junk/ the simple backup file name for src/patch/util.c is /junk/src/patch/util.c.

--binary

Read and write all files in binary mode, except for standard output and /dev/tty. This option has no effect on POSIX-conforming systems. On systems like DOS where this option makes a difference, the patch should be generated by diff -a --binary.

-c or --context

Interpret the patch file as a ordinary context diff.

-d dir or --directory=dir

Change to the directory dir immediately, before doing anything else.

-D define or --ifdef=define

Use the #ifdef ... #endif construct to mark changes, with define as the differentiating symbol.

--dry-run

Print the results of applying the patches without actually changing any files.

-e or --ed

Interpret the patch file as an ed script.

-E or --remove-empty-files

Remove output files that are empty after the patches have been applied. Normally this option is unnecessary, since patch can examine the time stamps on the header to determine whether a file should exist after patching. However, if the input is not a context diff or if patch is conforming to POSIX, patch does not remove empty patched files unless this option is given. When patch removes a file, it also attempts to remove any empty ancestor directories.

-f or --force

Assume that the user knows exactly what he or she is doing, and do not ask any questions. Skip patches whose headers do not say which file is to be patched; patch files even though they have the wrong version for the Prereq: line in the patch; and assume that patches are not reversed even if they look like they are. This option does not suppress commentary; use -s for that.

-F num or --fuzz=num

Set the maximum fuzz factor. This option only applies to diffs that have context, and causes patch to ignore up to that many lines in looking for places to install a hunk. Note that a larger fuzz factor increases the odds of a faulty patch. The default fuzz factor is 2, and it may not be set to more than the number of lines of context in the context diff, ordinarily 3.

-g num or --get=num

This option controls patch's actions when a file is under RCS or SCCS control, and does not exist or is read-only and matches the default version, or when a file is under ClearCase control and does not exist. If num is positive, patch gets (or checks out) the file from the revision control system; if zero, patch ignores RCS, ClearCase, and SCCS and does not get the file; and if negative, patch asks the user whether to get the file. The default value of this option is given by the value of the PATCH_GET environment variable if it is set; if not, the default value is zero if patch is conforming to POSIX, negative otherwise.

--help

Print a summary of options and exit.

-i patchfile or --input=patchfile

Read the patch from patchfile. If patchfile is -, read from standard input, the default.

-l or --ignore-whitespace

Match patterns loosely, in case tabs or spaces have been munged in your files. Any sequence of one or more blanks in the patch file matches any sequence in the original file, and sequences of blanks at the ends of lines are ignored. Normal characters must still match exactly. Each line of the context must still match a line in the original file.

-n or --normal

Interpret the patch file as a normal diff.

-N or --forward

Ignore patches that seem to be reversed or already applied. See also -R.

-o outfile or --output=outfile

Send output to outfile instead of patching files in place.

-pnum or --strip=num

Strip the smallest prefix containing num leading slashes from each file name found in the patch file. A sequence of one or more adjacent slashes is counted as a single slash. This controls how file names found in the patch file are treated, in case you keep your files in a different directory than the person who sent out the patch. For example, supposing the file name in the patch file was

/u/howard/src/blurfl/blurfl.c
 

setting -p0 gives the entire file name unmodified, -p1 gives

u/howard/src/blurfl/blurfl.c
 

without the leading slash, -p4 gives

blurfl/blurfl.c
 

and not specifying -p at all just gives you blurfl.c. Whatever you end up with is looked for either in the current directory, or the directory specified by the -d option.

--posix

Conform more strictly to the POSIX standard, as follows.

*

Take the first existing file from the list (old, new, index) when intuiting file names from diff headers.

*

Do not remove files that are empty after patching.

*

Do not ask whether to get files from RCS, ClearCase, or SCCS.

*

Require that all options precede the files in the command line.

*

Do not backup files when there is a mismatch.

--quoting-style=word

Use style word to quote output names. The word should be one of the following:

literal

Output names as-is.

shell

Quote names for the shell if they contain shell metacharacters or would cause ambiguous output.

shell-always

Quote names for the shell, even if they would normally not require quoting.

c

Quote names as for a C language string.

escape

Quote as with c except omit the surrounding double-quote characters.

You can specify the default value of the --quoting-style option with the environment variable QUOTING_STYLE. If that environment variable is not set, the default value is shell.

-r rejectfile or --reject-file=rejectfile

Put rejects into rejectfile instead of the default .rej file.

-R or --reverse

Assume that this patch was created with the old and new files swapped. (Yes, I'm afraid that does happen occasionally, human nature being what it is.) patch attempts to swap each hunk around before applying it. Rejects come out in the swapped format. The -R option does not work with ed diff scripts because there is too little information to reconstruct the reverse operation.

If the first hunk of a patch fails, patch reverses the hunk to see if it can be applied that way. If it can, you are asked if you want to have the -R option set. If it can't, the patch continues to be applied normally. (Note: this method cannot detect a reversed patch if it is a normal diff and if the first command is an append (i.e. it should have been a delete) since appends always succeed, due to the fact that a null context matches anywhere. Luckily, most patches add or change lines rather than delete them, so most reversed normal diffs begin with a delete, which fails, triggering the heuristic.)

-s or --silent or --quiet

Work silently, unless an error occurs.

-t or --batch

Suppress questions like -f, but make some different assumptions: skip patches whose headers do not contain file names (the same as -f); skip patches for which the file has the wrong version for the Prereq: line in the patch; and assume that patches are reversed if they look like they are.

-T or --set-time

Set the modification and access times of patched files from time stamps given in context diff headers, assuming that the context diff headers use local time. This option is not recommended, because patches using local time cannot easily be used by people in other time zones, and because local time stamps are ambiguous when local clocks move backwards during daylight-saving time adjustments. Instead of using this option, generate patches with UTC and use the -Z or --set-utc option instead.

-u or --unified

Interpret the patch file as a unified context diff.

-v or --version

Print out patch's revision header and patch level, and exit.

-V method or --version-control=method

Use method to determine backup file names. The method can also be given by the PATCH_VERSION_CONTROL (or, if that's not set, the VERSION_CONTROL) environment variable, which is overridden by this option. The method does not affect whether backup files are made; it affects only the names of any backup files that are made.

The value of method is like the GNU Emacs `version-control' variable; patch also recognizes synonyms that are more descriptive. The valid values for method are (unique abbreviations are accepted):

existing or nil

Make numbered backups of files that already have them, otherwise simple backups. This is the default.

numbered or t

Make numbered backups. The numbered backup file name for F is F.~N~ where N is the version number.

simple or never

Make simple backups. The -B or --prefix, -Y or --basename-prefix, and -z or --suffix options specify the simple backup file name. If none of these options are given, then a simple backup suffix is used; it is the value of the SIMPLE_BACKUP_SUFFIX environment variable if set, and is .orig otherwise.

With numbered or simple backups, if the backup file name is too long, the backup suffix ~ is used instead; if even appending ~ would make the name too long, then ~ replaces the last character of the file name.

--verbose

Output extra information about the work being done.

-x num or --debug=num

Set internal debugging flags of interest only to patch patchers.

-Y pref or --basename-prefix=pref

Prefix pref to the basename of a file name when generating its simple backup file name. For example, with -Y .del/ the simple backup file name for src/patch/util.c is src/patch/.del/util.c.

-z suffix or --suffix=suffix

Use suffix as the simple backup suffix. For example, with -z - the simple backup file name for src/patch/util.c is src/patch/util.c-. The backup suffix may also be specified by the SIMPLE_BACKUP_SUFFIX environment variable, which is overridden by this option.

-Z or --set-utc

Set the modification and access times of patched files from time stamps given in context diff headers, assuming that the context diff headers use Coordinated Universal Time (UTC, often known as GMT). Also see the -T or --set-time option.

The -Z or --set-utc and -T or --set-time options normally refrain from setting a file's time if the file's original time does not match the time given in the patch header, or if its contents do not match the patch exactly. However, if the -f or --force option is given, the file time is set regardless.

Due to the limitations of diff output format, these options cannot update the times of files whose contents have not changed. Also, if you use these options, you should remove (e.g. with make clean) all files that depend on the patched files, so that later invocations of make do not get confused by the patched files' times.

ENVIRONMENT

PATCH_GET

This specifies whether patch gets missing or read-only files from RCS, ClearCase, or SCCS by default; see the -g or --get option.

POSIXLY_CORRECT

If set, patch conforms more strictly to the POSIX standard by default: see the --posix option.

QUOTING_STYLE

Default value of the --quoting-style option.

SIMPLE_BACKUP_SUFFIX

Extension to use for simple backup file names instead of .orig.

TMPDIR, TMP, TEMP

Directory to put temporary files in; patch uses the first environment variable in this list that is set. If none are set, the default is system-dependent; it is normally /tmp on Unix hosts.

VERSION_CONTROL or PATCH_VERSION_CONTROL

Selects version control style; see the -v or --version-control option.

FILES

$TMPDIR/p*

temporary files

/dev/tty

controlling terminal; used to get answers to questions asked of the user

SEE ALSO

diff(1), ed(1)

Marshall T. Rose and Einar A. Stefferud, Proposed Standard for Message Encapsulation, Internet RFC 934 <URL:ftp://ftp.isi.edu/in-notes/rfc934.txt> (1985-01).