PATCH(1)                    General Commands Manual                   PATCH(1)

       patch - apply a diff file to an original

       patch [options] [originalfile [patchfile]]

       but usually just

       patch -pnum <patchfile

       patch takes a patch file patchfile containing a difference listing pro-
       duced by the diff program and applies those differences to one or  more
       original  files, producing patched versions.  Normally the patched ver-
       sions 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 usu-
       ally taken from the patch file, but if there's  just  one  file  to  be
       patched it can be 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  con-
       taining  a  diff  listing  to patch, and it should work.  If the entire
       diff is indented by a consistent amount, if lines end in CRLF, or if  a
       diff  is  encapsulated  one  or  more times by prepending "- " to lines
       starting with "-" as specified by Internet RFC 934, this is taken  into
       account.   After  removing  indenting or encapsulation, lines beginning
       with # are ignored, as they are considered to be comments.

       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 an-
       other scan is made.  (The default maximum fuzz factor is 2.)

       Hunks with less prefix context  than  suffix  context  (after  applying
       fuzz)  must  apply  at the start of the file if their first line number
       is 1.  Hunks with more prefix context than suffix context (after apply-
       ing fuzz) must apply at the end of the file.

       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 unified or context diff format.  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 speci-
       fied 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:

        o 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.

        o 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.

        o 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:

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

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

        o If no named files exist, no RCS, ClearCase, Perforce, 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.

        o 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

       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 con-
       taining 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.

       -b  or  --backup
          Make  backup  files.   That is, when patching a file, rename or copy
          the original instead of removing it.  See the -V  or  --version-con-
          trol option for details about how backup file names are determined.

          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.

          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
          Use  the  simple  method  to determine backup file names (see the -V
          method or --version-control method option), and  append  pref  to  a
          file  name  when generating its backup file name.  For example, with
          -B /junk/ the  simple  backup  file  name  for  src/patch/util.c  is

          Write  all  files  in  binary  mode,  except for standard output and
          /dev/tty.  When reading, disable the heuristic for transforming CRLF
          line  endings  into LF line endings.  This option is needed on POSIX
          systems when applying patches generated on non-POSIX systems to non-
          POSIX  files.  (On POSIX systems, file reads and writes never trans-
          form line endings. On Windows, reads and writes  do  transform  line
          endings by default, and patches should be generated by diff --binary
          when line endings are significant.)

       -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.

          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  ap-
          plied.  Normally this option is unnecessary, since patch can examine
          the time stamps on the header to determine whether a file should ex-
          ist  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  of
          context 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.  A fuzz factor greater than or equal to the number of
          lines of context in the context diff, ordinarily 3, ignores all con-

       -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 de-
          fault version, or when a file is under ClearCase or Perforce 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, Perforce, 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 environ-
          ment variable if it is set; if not, the default value is zero.

          Print a summary of options and exit.

       -i patchfile  or  --input=patchfile
          Read  the  patch from patchfile.  If patchfile is -, read from stan-
          dard 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.

       --merge or --merge=merge or --merge=diff3
          Merge  a  patch  file into the original files similar to diff3(1) or
          merge(1).  If a conflict is  found,  patch  outputs  a  warning  and
          brackets  the  conflict  with  <<<<<<< and >>>>>>> lines.  A typical
          conflict will look like this:

              lines from the original file
              original lines from the patch
              new lines from the patch

          The optional argument of --merge determines the  output  format  for
          conflicts: the diff3 format shows the ||||||| section with the orig-
          inal lines from the patch; in the  merge  format,  this  section  is
          missing.  The merge format is the default.

          This  option  implies --forward and does not take the --fuzz=num op-
          tion into account.

       -n  or  --normal
          Interpret the patch file as a normal diff.

       -N  or  --forward
          When a patch does not apply, patch usually checks if the patch looks
          like  it  has  been  applied  already by trying to reverse-apply the
          first hunk.  The --forward option prevents that.  See also -R.

       -o outfile  or  --output=outfile
          Send output to outfile instead of patching files in place.   Do  not
          use  this option if outfile is one of the files to be patched.  When
          outfile is -, send output to standard output, and send any  messages
          that would usually go to standard output to standard error.

       -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  adja-
          cent  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


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


       without the leading slash, -p4 gives


       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.

          Conform more strictly to the POSIX standard, as follows.

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

           o Do not remove files that are empty after patching.

           o Do not ask whether to get files from RCS, ClearCase, Perforce, or

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

           o Do not backup files when there is a mismatch.

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

                 Output names as-is.

          shell  Quote  names  for the shell if they contain shell metacharac-
                 ters or would cause ambiguous output.

                 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

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

       -r rejectfile  or  --reject-file=rejectfile
          Put rejects into rejectfile instead of the default .rej file.   When
          rejectfile is -, discard rejects.

       -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  na-
          ture being what it is.)  patch attempts to swap each hunk around be-
          fore applying it.  Rejects come out in the swapped format.   The  -R
          option  does not work with ed diff scripts because there is too lit-
          tle 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 re-
          versed normal diffs begin with a delete, which fails, triggering the

          Behave  as  requested when trying to modify a read-only file: ignore
          the potential problem, warn about it (the default), or fail.

          Produce reject files in the specified format (either context or uni-
          fied).  Without this option, rejected hunks come out in unified diff
          format if the input patch was of that format, otherwise in  ordinary
          context diff form.

       -s  or  --silent  or  --quiet
          Work silently, unless an error occurs.

          When  looking  for input files, follow symbolic links.  Replaces the
          symbolic links, instead of modifying the files  the  symbolic  links
          point to.  Git-style patches to symbolic links will no longer apply.
          This option exists for backwards compatibility  with  previous  ver-
          sions of patch; its use is discouraged.

       -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.  Unless specified in the  time
          stamps, assume that the context diff headers use local time.

          Use  of  this option with time stamps that do not include time zones
          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-sav-
          ing  time  adjustments.   Make  sure  that  time stamps include time
          zones, or generate patches with UTC and use the -Z or --set-utc  op-
          tion 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  VER-
          SION_CONTROL)  environment variable, which is overridden by this op-
          tion.  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' vari-
          able; 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-pre-
             fix, 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 envi-
             ronment 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.

          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
          Use the simple method to determine backup file  names  (see  the  -V
          method  or  --version-control method option), and prefix pref to the
          basename of a file name when generating its 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 the simple method to determine backup file  names  (see  the  -V
          method  or  --version-control  method option), and use suffix as the
          suffix.   For  example,  with  -z -  the  backup   file   name   for
          src/patch/util.c is src/patch/util.c-.

       -Z  or  --set-utc
          Set  the  modification  and  access times of patched files from time
          stamps given in context diff headers. Unless specified in  the  time
          stamps, assume that the context diff headers use Coordinated Univer-
          sal Time (UTC, often known as GMT).  Also see the -T  or  --set-time

          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.

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

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

          Default value of the --quoting-style option.

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

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

          Selects version control style; see the -v or  --version-control  op-

          temporary files

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

       diff(1), ed(1), merge(1).

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

       There are several things you should bear in mind if you are going to be
       sending out patches.

       Create  your  patch  systematically.   A  good  method  is  the command
       diff -Naur old new where old and new identify the old and new  directo-
       ries.   The names old and new should not contain any slashes.  The diff
       command's headers should have dates and times in Universal  Time  using
       traditional  Unix  format,  so  that patch recipients can use the -Z or
       --set-utc option.  Here is an example command, using Bourne shell  syn-

              LC_ALL=C TZ=UTC0 diff -Naur gcc-2.7 gcc-2.8

       Tell  your  recipients how to apply the patch by telling them which di-
       rectory to cd to, and which patch options to use.   The  option  string
       -Np1 is recommended.  Test your procedure by pretending to be a recipi-
       ent and applying your patch to a copy of the original files.

       You can save people a lot of grief by keeping a patchlevel.h file which
       is  patched to increment the patch level as the first diff in the patch
       file you send out.  If you put a Prereq: line in  with  the  patch,  it
       won't let them apply patches out of order without some warning.

       You  can create a file by sending out a diff that compares /dev/null or
       an empty file dated the Epoch (1970-01-01 00:00:00 UTC) to the file you
       want to create.  This only works if the file you want to create doesn't
       exist already in the target directory.  Conversely, you  can  remove  a
       file by sending out a context diff that compares the file to be deleted
       with an empty file dated the Epoch.  The file will  be  removed  unless
       patch  is conforming to POSIX and the -E or --remove-empty-files option
       is not given.  An easy way to generate patches that create  and  remove
       files is to use GNU diff's -N or --new-file option.

       If  the recipient is supposed to use the -pN option, do not send output
       that looks like this:

              diff -Naur v2.0.29/prog/README prog/README
              --- v2.0.29/prog/README   Mon Mar 10 15:13:12 1997
              +++ prog/README   Mon Mar 17 14:58:22 1997

       because the two file names have different numbers of slashes, and  dif-
       ferent  versions  of  patch  interpret  the file names differently.  To
       avoid confusion, send output that looks like this instead:

              diff -Naur v2.0.29/prog/README v2.0.30/prog/README
              --- v2.0.29/prog/README   Mon Mar 10 15:13:12 1997
              +++ v2.0.30/prog/README   Mon Mar 17 14:58:22 1997

       Avoid sending patches that compare backup file names like  README.orig,
       since  this  might confuse patch into patching a backup file instead of
       the real file.  Instead, send patches that compare the same  base  file
       names in different directories, e.g. old/README and new/README.

       Take  care not to send out reversed patches, since it makes people won-
       der whether they already applied the patch.

       Try not to have your patch modify derived files (e.g. the file  config-
       ure  where  there  is a line configure: in your makefile),
       since the recipient should be able to regenerate the derived files any-
       way.  If you must send diffs of derived files, generate the diffs using
       UTC, have the recipients apply the patch with the -Z or  --set-utc  op-
       tion,  and  have them remove any unpatched files that depend on patched
       files (e.g. with make clean).

       While you may be able to get away with putting 582 diff  listings  into
       one  file, it may be wiser to group related patches into separate files
       in case something goes haywire.

       Diagnostics generally indicate that patch  couldn't  parse  your  patch

       If  the  --verbose  option  is given, the message Hmm... indicates that
       there is unprocessed text in the patch file and that patch is  attempt-
       ing  to  intuit  whether there is a patch in that text and, if so, what
       kind of patch it is.

       patch's exit status is 0 if all hunks are applied  successfully,  1  if
       some  hunks  cannot  be applied or there were merge conflicts, and 2 if
       there is more serious trouble.  When applying a set  of  patches  in  a
       loop  it  behooves  you  to check this exit status so you don't apply a
       later patch to a partially patched file.

       Context diffs cannot reliably represent the  creation  or  deletion  of
       empty  files,  empty  directories,  or  special  files such as symbolic
       links.  Nor can they represent changes to file metadata like ownership,
       permissions, or whether one file is a hard link to another.  If changes
       like these are also  required,  separate  instructions  (e.g.  a  shell
       script) to accomplish them should accompany the patch.

       patch  cannot tell if the line numbers are off in an ed script, and can
       detect bad line numbers in a normal diff only when it finds a change or
       deletion.   A  context diff using fuzz factor 3 may have the same prob-
       lem.  You should probably do a context diff in these cases  to  see  if
       the  changes  made  sense.   Of  course,  compiling without errors is a
       pretty good indication that the patch worked, but not always.

       patch usually produces the correct results, even when it has  to  do  a
       lot  of  guessing.   However,  the results are guaranteed to be correct
       only when the patch is applied to exactly the same version of the  file
       that the patch was generated from.

       The  POSIX standard specifies behavior that differs from patch's tradi-
       tional behavior.  You should be aware of these differences if you  must
       interoperate  with patch versions 2.1 and earlier, which do not conform
       to POSIX.

        o In traditional patch, the -p option's operand was  optional,  and  a
          bare  -p was equivalent to -p0.  The -p option now requires an oper-
          and, and -p 0 is now equivalent to -p0.  For maximum  compatibility,
          use options like -p0 and -p1.

          Also,  traditional  patch simply counted slashes when stripping path
          prefixes; patch now counts pathname components.  That is, a sequence
          of  one  or more adjacent slashes now counts as a single slash.  For
          maximum portability, avoid sending patches  containing  //  in  file

        o In  traditional patch, backups were enabled by default.  This behav-
          ior is now enabled with the -b or --backup option.

          Conversely, in POSIX patch, backups are never made, even when  there
          is  a  mismatch.   In  GNU  patch, this behavior is enabled with the
          --no-backup-if-mismatch option, or by conforming to POSIX  with  the
          --posix  option  or by setting the POSIXLY_CORRECT environment vari-

          The -b suffix option of  traditional  patch  is  equivalent  to  the
          -b -z suffix options of GNU patch.

        o Traditional  patch  used a complicated (and incompletely documented)
          method to intuit the name of the file to be patched from  the  patch
          header.   This  method  did  not  conform  to  POSIX,  and had a few
          gotchas.  Now patch uses a different, equally complicated (but  bet-
          ter  documented) method that is optionally POSIX-conforming; we hope
          it has fewer gotchas.  The two methods are compatible  if  the  file
          names in the context diff header and the Index: line are all identi-
          cal after prefix-stripping.  Your patch is  normally  compatible  if
          each header's file names all contain the same number of slashes.

        o When  traditional patch asked the user a question, it sent the ques-
          tion to standard error and looked for an answer from the first  file
          in  the following list that was a terminal: standard error, standard
          output, /dev/tty, and standard input.  Now patch sends questions  to
          standard  output  and gets answers from /dev/tty.  Defaults for some
          answers have been changed so that patch never goes into an  infinite
          loop when using default answers.

        o Traditional patch exited with a status value that counted the number
          of bad hunks, or with status 1 if there was real trouble.  Now patch
          exits  with  status  1  if some hunks failed, or with 2 if there was
          real trouble.

        o Limit yourself to the following options  when  sending  instructions
          meant to be executed by anyone running GNU patch, traditional patch,
          or a patch that conforms to POSIX.  Spaces are  significant  in  the
          following list, and operands are required.

             -d dir
             -D define
             -o outfile
             -r rejectfile

       Please report bugs via email to <>.

       If code has been duplicated (for instance with #ifdef OLDCODE ... #else
       ... #endif), patch is incapable of patching both versions, and,  if  it
       works  at  all,  will  likely patch the wrong one, and tell you that it
       succeeded to boot.

       If you apply a patch you've already applied, patch thinks it is  a  re-
       versed  patch,  and  offers  to un-apply the patch.  This could be con-
       strued as a feature.

       Computing how to merge a hunk is significantly harder  than  using  the
       standard  fuzzy algorithm.  Bigger hunks, more context, a bigger offset
       from the original location, and a worse match all  slow  the  algorithm

       Copyright (C) 1984, 1985, 1986, 1988 Larry Wall.
       Copyright  (C)  1989,  1990,  1991, 1992, 1993, 1994, 1995, 1996, 1997,
       1998, 1999, 2000, 2001, 2002, 2009 Free Software Foundation, Inc.

       Permission is granted to make and distribute verbatim  copies  of  this
       manual  provided  the  copyright  notice and this permission notice are
       preserved on all copies.

       Permission is granted to copy and distribute modified versions of  this
       manual under the conditions for verbatim copying, provided that the en-
       tire resulting derived work is distributed under the terms of a permis-
       sion notice identical to this one.

       Permission  is granted to copy and distribute translations of this man-
       ual into another language, under the above conditions for modified ver-
       sions,  except  that this permission notice may be included in transla-
       tions approved by the copyright holders instead of in the original Eng-

       Larry  Wall  wrote  the original version of patch.  Paul Eggert removed
       patch's arbitrary limits; added support for binary files, setting  file
       times,  and deleting files; and made it conform better to POSIX.  Other
       contributors include Wayne Davison,  who  added  unidiff  support,  and
       David  MacKenzie,  who added configuration and backup support.  Andreas
       Grunbacher added support for merging.

GNU                                                                   PATCH(1)
Man Pages Copyright Respective Owners. Site Copyright (C) 1994 - 2024 Hurricane Electric. All Rights Reserved.