Patch

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.