IABSD.fr/src/usr.bin/diff/diff.1

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• Author : jmc
  Date : 2024-12-03 07:09:14
  Hash : 394d9b5a
  Message : glob patterns described in glob(7) not fnmatch(3); from evan silberman ok sthen semarie millert

• usr.bin/diff/diff.1

• .\" $OpenBSD: diff.1,v 1.52 2024/12/03 07:09:14 jmc Exp $
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  .\"     @(#)diff.1	8.1 (Berkeley) 6/30/93
  .\"
  .Dd $Mdocdate: December 3 2024 $
  .Dt DIFF 1
  .Os
  .Sh NAME
  .Nm diff
  .Nd differential file and directory comparator
  .Sh SYNOPSIS
  .Nm diff
  .Op Fl abdipTtw
  .Oo
  .Fl c | e | f |
  .Fl n | q | u
  .Oc
  .Op Fl I Ar pattern
  .Op Fl L Ar label
  .Ar file1 file2
  .Nm diff
  .Op Fl abdipTtw
  .Op Fl I Ar pattern
  .Op Fl L Ar label
  .Fl C Ar number
  .Ar file1 file2
  .Nm diff
  .Op Fl abditw
  .Op Fl I Ar pattern
  .Fl D Ar string
  .Ar file1 file2
  .Nm diff
  .Op Fl abdipTtw
  .Op Fl I Ar pattern
  .Op Fl L Ar label
  .Fl U Ar number
  .Ar file1 file2
  .Nm diff
  .Op Fl abdiNPprsTtw
  .Oo
  .Fl c | e | f |
  .Fl n | q | u
  .Oc
  .Op Fl I Ar pattern
  .Bk -words
  .Op Fl L Ar label
  .Op Fl S Ar name
  .Op Fl X Ar file
  .Op Fl x Ar pattern
  .Ek
  .Ar dir1 dir2
  .Sh DESCRIPTION
  The
  .Nm
  utility compares the contents of
  .Ar file1
  and
  .Ar file2
  and writes to the standard output the list of changes necessary to
  convert one file into the other.
  No output is produced if the files are identical.
  .Pp
  Output options (mutually exclusive):
  .Bl -tag -width Ds
  .It Fl C Ar number
  Like
  .Fl c
  but produces a diff with
  .Ar number
  lines of context.
  .It Fl c
  Produces a diff with 3 lines of context.
  With
  .Fl c
  the output format is modified slightly:
  the output begins with identification of the files involved and
  their creation dates and then each change is separated
  by a line with fifteen
  .Li * Ns 's .
  The lines removed from
  .Ar file1
  are marked with
  .Sq \-\ \& ;
  those added to
  .Ar file2
  are marked
  .Sq +\ \& .
  Lines which are changed from one file to the other are marked in
  both files with
  .Sq !\ \& .
  Changes which lie within 3 lines of each other are grouped together on
  output.
  .It Fl D Ar string
  Creates a merged version of
  .Ar file1
  and
  .Ar file2
  on the standard output, with C preprocessor controls included so that
  a compilation of the result without defining
  .Ar string
  is equivalent to compiling
  .Ar file1 ,
  while defining
  .Ar string
  will yield
  .Ar file2 .
  .It Fl e
  Produces output in a form suitable as input for the editor utility,
  .Xr ed 1 ,
  which can then be used to convert file1 into file2.
  .Pp
  Extra commands are added to the output when comparing directories with
  .Fl e ,
  so that the result is a
  .Xr sh 1
  script for converting text files which are common to the two directories
  from their state in
  .Ar dir1
  to their state in
  .Ar dir2 .
  .It Fl f
  Identical output to that of the
  .Fl e
  flag, but in reverse order.
  It cannot be digested by
  .Xr ed 1 .
  .It Fl n
  Produces a script similar to that of
  .Fl e ,
  but in the opposite order and with a count of changed lines on each
  insert or delete command.
  This is the form used by
  .Xr rcsdiff 1 .
  .It Fl q
  Just print a line when the files differ.
  Does not output a list of changes.
  .It Fl U Ar number
  Like
  .Fl u
  but produces a diff with
  .Ar number
  lines of context.
  .It Fl u
  Produces a
  .Em unified
  diff with 3 lines of context.
  A unified diff is similar to the context diff produced by the
  .Fl c
  option.
  However, unlike with
  .Fl c ,
  all lines to be changed (added and/or removed) are present in
  a single section.
  .El
  .Pp
  Comparison options:
  .Bl -tag -width Ds
  .It Fl a
  Treat all files as ASCII text.
  Normally
  .Nm
  will simply print
  .Dq Binary files ... differ
  if files contain binary characters.
  Use of this option forces
  .Nm
  to produce a diff.
  .It Fl b
  Causes trailing blanks (spaces and tabs) to be ignored, and other
  strings of blanks to compare equal.
  .It Fl d
  Try very hard to produce a diff as small as possible.
  This may consume a lot of processing power and memory when processing
  large files with many changes.
  .It Fl I Ar pattern
  Ignores changes, insertions, and deletions whose lines match the
  extended regular expression
  .Ar pattern .
  Multiple
  .Fl I
  patterns may be specified.
  All lines in the change must match some pattern for the change to be
  ignored.
  See
  .Xr re_format 7
  for more information on regular expression patterns.
  .It Fl i
  Ignores the case of letters.
  E.g.,
  .Dq A
  will compare equal to
  .Dq a .
  .It Fl L Ar label
  Print
  .Ar label
  instead of the first (and second, if this option is specified twice)
  file name and time in the context or unified diff header.
  .It Fl p
  With unified and context diffs, show with each change
  the first 40 characters of the last line before the context beginning
  with a letter, an underscore or a dollar sign.
  For C source code following standard layout conventions, this will
  show the prototype of the function the change applies to.
  .It Fl T
  Print a tab rather than a space before the rest of the line for the
  normal, context or unified output formats.
  This makes the alignment of tabs in the line consistent.
  .It Fl t
  Will expand tabs in output lines.
  Normal or
  .Fl c
  output adds character(s) to the front of each line which may screw up
  the indentation of the original source lines and make the output listing
  difficult to interpret.
  This option will preserve the original source's indentation.
  .It Fl w
  Is similar to
  .Fl b
  but causes whitespace (blanks and tabs) to be totally ignored.
  E.g.,
  .Dq if (\ \&a == b \&)
  will compare equal to
  .Dq if(a==b) .
  .El
  .Pp
  Directory comparison options:
  .Bl -tag -width Ds
  .It Fl N
  If a file is found in only one directory, act as if it was found in the
  other directory too but was of zero size.
  .It Fl P
  If a file is found only in
  .Ar dir2 ,
  act as if it was found in
  .Ar dir1
  too but was of zero size.
  .It Fl r
  Causes application of
  .Nm
  recursively to common subdirectories encountered.
  .It Fl S Ar name
  Re-starts a directory
  .Nm
  in the middle, beginning with file
  .Ar name .
  .It Fl s
  Causes
  .Nm
  to report files which are the same, which are otherwise not mentioned.
  .It Fl X Ar file
  Exclude files and subdirectories from comparison whose basenames match
  lines in
  .Ar file .
  Multiple
  .Fl X
  options may be specified.
  .It Fl x Ar pattern
  Exclude files and subdirectories from comparison whose basenames match
  .Ar pattern .
  Patterns are matched using shell-style globbing as described in
  .Xr glob 7 .
  Multiple
  .Fl x
  options may be specified.
  .El
  .Pp
  If both arguments are directories,
  .Nm
  sorts the contents of the directories by name, and then runs the
  regular file
  .Nm
  algorithm, producing a change list,
  on text files which are different.
  Binary files which differ,
  common subdirectories, and files which appear in only one directory
  are described as such.
  In directory mode only regular files and directories are compared.
  If a non-regular file such as a device special file or FIFO
  is encountered, a diagnostic message is printed.
  .Pp
  If only one of
  .Ar file1
  and
  .Ar file2
  is a directory,
  .Nm
  is applied to the non-directory file and the file contained in
  the directory file with a filename that is the same as the
  last component of the non-directory file.
  .Pp
  If either
  .Ar file1
  or
  .Ar file2
  is
  .Sq - ,
  the standard input is
  used in its place.
  .Ss Output Style
  The default (without
  .Fl e ,
  .Fl c ,
  or
  .Fl n
  .\" -C
  options)
  output contains lines of these forms, where
  .Va XX , YY , ZZ , QQ
  are line numbers respective of file order.
  .Pp
  .Bl -tag -width "XX,YYcZZ,QQ" -compact
  .It Li XX Ns Ic a Ns Li YY
  At (the end of) line
  .Va XX
  of
  .Ar file1 ,
  append the contents
  of line
  .Va YY
  of
  .Ar file2
  to make them equal.
  .It Li XX Ns Ic a Ns Li YY,ZZ
  Same as above, but append the range of lines,
  .Va YY
  through
  .Va ZZ
  of
  .Ar file2
  to line
  .Va XX
  of file1.
  .It Li XX Ns Ic d Ns Li YY
  At line
  .Va XX
  delete
  the line.
  The value
  .Va YY
  tells to which line the change would bring
  .Ar file1
  in line with
  .Ar file2 .
  .It Li XX,YY Ns Ic d Ns Li ZZ
  Delete the range of lines
  .Va XX
  through
  .Va YY
  in
  .Ar file1 .
  .It Li XX Ns Ic c Ns Li YY
  Change the line
  .Va XX
  in
  .Ar file1
  to the line
  .Va YY
  in
  .Ar file2 .
  .It Li XX,YY Ns Ic c Ns Li ZZ
  Replace the range of specified lines with the line
  .Va ZZ .
  .It Li XX,YY Ns Ic c Ns Li ZZ,QQ
  Replace the range
  .Va XX , Ns Va YY
  from
  .Ar file1
  with the range
  .Va ZZ , Ns Va QQ
  from
  .Ar file2 .
  .El
  .Pp
  These lines resemble
  .Xr ed 1
  subcommands to convert
  .Ar file1
  into
  .Ar file2 .
  The line numbers before the action letters pertain to
  .Ar file1 ;
  those after pertain to
  .Ar file2 .
  Thus, by exchanging
  .Ic a
  for
  .Ic d
  and reading the line in reverse order, one can also
  determine how to convert
  .Ar file2
  into
  .Ar file1 .
  As in
  .Xr ed 1 ,
  identical
  pairs (where num1 = num2) are abbreviated as a single
  number.
  .Sh FILES
  .Bl -tag -width /tmp/diff.XXXXXXXX -compact
  .It Pa /tmp/diff. Ns Ar XXXXXXXX
  Temporary file used when comparing a device or the standard input.
  Note that the temporary file is unlinked as soon as it is created
  so it will not show up in a directory listing.
  .El
  .Sh EXIT STATUS
  The
  .Nm
  utility exits with one of the following values:
  .Pp
  .Bl -tag -width Ds -offset indent -compact
  .It 0
  No differences were found.
  .It 1
  Differences were found.
  .It >1
  An error occurred.
  .El
  .Sh SEE ALSO
  .Xr cmp 1 ,
  .Xr comm 1 ,
  .Xr diff3 1 ,
  .Xr ed 1 ,
  .Xr patch 1 ,
  .Xr sdiff 1
  .Rs
  .%A James W. Hunt
  .%A M. Douglas McIlroy
  .%T "An Algorithm for Differential File Comparison"
  .%I AT&T Bell Laboratories
  .%J Computing Science Technical Report
  .%N 41
  .%D June 1976
  .Re
  .Sh STANDARDS
  The
  .Nm
  utility is compliant with the
  .St -p1003.1-2008
  specification.
  .Pp
  The flags
  .Op Fl aDdIiLNnPpqSsTtwXx
  are extensions to that specification.
  .Sh HISTORY
  A
  .Nm
  command appeared in
  .At v5 .