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PATCH(1)							      PATCH(1)



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 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 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, 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  con-
       texts  are  simply  null.)  The line numbers on the hunks in the reject
       file may be different than in the patch file: they reflect the approxi-
       mate  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:

	? 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 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.

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 --ver-
	  sion-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  sys-
	  tems.	 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 exam-
	  ine 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  fac-
	  tor  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 con-
	  text 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 vari-
	  able	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	 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.

       -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	 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

	     /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  metacharac-
		 ters 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	 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.

       -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 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
	  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 VER-
	  SION_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'	 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.

       --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 sim-
	  ple 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 environ-
	  ment 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).

NOTES FOR PATCH SENDERS
       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-
       tax:

	  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
       directory  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: configure.in  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
       option, 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
       Diagnostics  generally  indicate	 that  patch couldn't parse your patch
       file.

       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, 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.

CAVEATS
       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.  Until a suitable interactive interface is added, you should prob-
       ably 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.

COMPATIBILITY ISSUES
       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.

	? In traditional patch, the -p option's operand was  optional,	and  a
	  bare	-p  was	 equivalent  to	 -p0.	The  -p option now requires an
	  operand, and -p 0 is now equivalent to -p0.  For maximum compatibil-
	  ity, 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
	  names.

	? 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-
	  able.

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

	? 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
	  better  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
	  identical after prefix-stripping.  Your patch is normally compatible
	  if  each header's file names all contain the same number of slashes.

	? 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.

	? 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.

	? 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.

	     -c
	     -d dir
	     -D define
	     -e
	     -l
	     -n
	     -N
	     -o outfile
	     -pnum
	     -R
	     -r rejectfile

BUGS
       Please report bugs via email to <bug-gnu-utils@gnu.org>.

       patch could be smarter about partial matches, excessively deviant  off-
       sets and swapped code, but that would take an extra pass.

       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
       reversed	 patch,	 and offers to un-apply the patch.  This could be con-
       strued as a feature.

COPYING
       Copyright 1984, 1985, 1986, 1988 Larry Wall.
       Copyright 1989, 1990, 1991, 1992, 1993, 1994, 1995,  1996,  1997,  1998
       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
       entire  resulting derived work is distributed under the terms of a per-
       mission notice identical to this one.

       Permission is granted to	 copy  and  distribute	translations  of  this
       manual  into  another language, under the above conditions for modified
       versions, except that this permission notice may be included in	trans-
       lations	approved  by  the copyright holders instead of in the original
       English.

AUTHORS
       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.



GNU				  1998/03/21			      PATCH(1)
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