patch - apply changes to files


     patch [-blNR] [-c | -e | -n | -u]  [-d dir]  [-D define]  [-
     i patchfile] [-o outfile] [-p num] [-r rejectfile] [file]


     The patch command reads a source (patch) file containing any
     of the three forms of difference (diff) listings produced by
     the diff(1) command (normal, context  or  in  the  style  of
     ed(1))  and  apply those differences to a file.  By default,
     patch reads from the standard input.

     patch attempts 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  will
     attempt  to apply each of them as if they came from separate
     patch files. (In this case the name of the patch  file  must
     be determinable for each diff listing.)


     The following options are supported:

     -b    Saves 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 will be overwritten. If
           multiple patches are applied to  the  same  file,  the
           .orig  file  will be written only for the first patch.
           When  the  -o  outfile  option  is   also   specified,
           file.orig  will not be created but, if outfile already
           exists, outfile.orig will be created.

     -c    Interprets the patch file as a context difference (the
           output  of  the command diff when the -c or -C options
           are specified).

     -d dir
           Changes the current directory to dir before processing
           as described in EXTENDED DESCRIPTION.

     -D define
           Marks changes with the C preprocessor construct:

           #ifdef define

     The option-argument define will be used as the differentiat-
     ing symbol.

     -e    Interprets the patch file as an ed script, rather than
           a diff script.

     -i patchfile
           Reads the patch information from the file named by the
           path name patchfile, rather than the standard input.

     -l    (The letter ell.) Causes any sequence of blank charac-
           ters in the difference script to match any sequence of
           blank characters in the input file.  Other  characters
           will be matched exactly.

     -n    Interprets the script as a normal difference.

     -N    Ignores patches where  the  differences  have  already
           been  applied to the file; by default, already-applied
           patches are rejected.

     -o outfile
           Instead of modifying the files (specified by the  file
           operand or the difference listings) directly, writes a
           copy of the file referenced by each  patch,  with  the
           appropriate  differences applied, to outfile. Multiple
           patches for a single  file  will  be  applied  to  the
           intermediate  versions of the file created by any pre-
           vious patches,  and  will  result  in  multiple,  con-
           catenated  versions  of the file being written to out-

     -p num
           For all path names in the patch file that indicate the
           names  of  files  to be patched, deletes num path name
           components from the beginning of each  path  name.  If
           the path name in the patch file is absolute, any lead-
           ing slashes are considered the first  component  (that
           is, -p 1 removes the leading slashes). Specifying -p 0
           causes the full path name to be used.  If  -p  is  not
           specified, only the basename (the final path name com-
           ponent) is used.

     -R    Reverses the sense  of  the  patch  script.  That  is,
           assumes  that  the  difference script was created from
           the new version to the old version. The -R option can-
           not be used with ed scripts. patch attempts to reverse
           each  portion  of  the  script  before  applying   it.
           Rejected  differences will 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 suc-
           cessful, the user will be prompted to determine if the
           -R option should be set.

     -r rejectfile
           Overrides the default reject file name. In the default
           case,  the  reject file will have the same name as the
           output file, with the suffix .rej appended to it.  See
           Patch Application.

     -u    Interprets the patch file as a unified context differ-
           ence, that is, the output of the command diff when the
           -u or -U options are specified.


     The following operand is supported:

     file  A path name of a file to patch.


     The -R option will 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 file name in the patch  file
     was /curds/whey/src/blurfl/blurfl.c:

        o  Setting -p 0 gives the entire path name unmodified.

        o  Setting -p 1 gives:


        o  Without the leading slash, -p 4 gives:


        o  Not specifying -p at all gives:


     When using -b in some file system implementations, the  sav-
     ing  of  a  .orig  file may produce unwanted results. In the
     case of 12-, 13-, or 14-character file names, on  file  sys-
     tems  supporting  14-character maximum file names, the .orig
     file will overwrite the new file.


     See environ(5) for descriptions of the following environment
     variables  that affect the execution of patch: LANG, LC_ALL,


     The output of patch the save files (.orig suffixes) and  the
     reject files (.rej suffixes) will be text files.


     A patch file may contain patching instructions for more than
     one  file.  File  names are determined as specified in Patch
     Determination. When the -b option  is  specified,  for  each
     patched  file,  the  original will 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 an -r option,
     the name of this file will be formed by appending the suffix
     .rej to the original file name.

  Patch File Format
     The patch file must contain zero or  more  lines  of  header
     information followed by one or more patches. Each patch must
     contain zero or more lines of file  name  identification  in
     the format produced by diff -c, and one or more sets of diff
     output, which are customarily called hunks.

     patch recognizes the  following  expression  in  the  header

           The file to be patched is named pathname.

     If all lines (including headers) within a patch  begin  with
     the  same  leading  sequence of blank characters, patch will
     remove this sequence before proceeding. Within  each  patch,
     if  the  type of difference is context, patch recognizes the
     following expressions:

     *** filename timestamp
           The patches arose from filename.

     --- filename timestamp
           The patches should be applied to filename.

     Each hunk within a patch must be the diff output to change a
     line  range  within  the original file. The line numbers for
     successive hunks within a  patch  must  occur  in  ascending

  File Name Determination
     If no file operand is specified, patch performs the  follow-
     ing steps to obtain a path name:

     1. If the patch contains the  strings  ***  and  ---,  patch
        strips  components  from  the beginning of each path name
        (depending on the presence or value of  the  -p  option),
        then tests for the existence of both files in the current
        directory (or directory specified with the -d option).

     2. If both files exist, patch assumes that no path name  can
        be  obtained  from  this  step. If the header information
        contains a line with the string Index:, patch strips com-
        ponents from the beginning of the path name (depending on
        -p), then tests for the existence of  this  file  in  the
        current  directory  (or  directory  specified with the -d

     3. If an SCCS directory exists  in  the  current  directory,
        patch  will  attempt  to perform a get -e SCCS/s.filename
        command to retrieve an editable version of the file.

     4. If no path name can be obtained by applying the  previous
        steps,  or if the path names obtained do not exist, patch
        will write a prompt to standard output and request a file
        name interactively from standard input.

  Patch Application
     If the -c, -e, -n, or  -u  option  is  present,  patch  will
     interpret  information within each hunk as a context differ-
     ence, an ed difference, a normal difference,  or  a  unified
     context  difference,  respectively. In the absence of any of
     these options, patch determines the type of difference based
     on the format of information within the hunk.

     For each hunk, patch begins 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
     scans 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  will take place, ignoring the first and
     last line of context. If that fails, the first two and  last
     two  lines  of context will be ignored and another scan will
     be made. Implementations may  search  more  extensively  for
     installation locations.

     If no location can be found, patch will append the  hunk  to
     the  reject  file.  The  rejected  hunk  will  be written in
     context-difference format regardless of the  format  of  the
     patch  file.  If the input was a normal or ed -style differ-
     ence, 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 will reflect the approximate locations
     for the failed hunks in the new file  rather  than  the  old

     If the type of patch is an ed diff, the  implementation  may
     accomplish the patching by invoking the ed command.


     The following exit values are returned:

     0     Successful completion.

     1     One or more lines were written to a reject file.

     >1    An error occurred.


     See attributes(5) for descriptions of the  following  attri-

    |       ATTRIBUTE TYPE        |       ATTRIBUTE VALUE       |
    | Availability                | SUNWcsu                     |
    | Interface Stability         | Standard                    |


     ed(1), diff(1), attributes(5), environ(5), standards(5)

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