diff(1) [v7 man page]

DIFF(1) 						      General Commands Manual							   DIFF(1)

NAME

       diff - differential file comparator

SYNOPSIS

       diff [ -efbh ] file1 file2

DESCRIPTION

       Diff  tells what lines must be changed in two files to bring them into agreement.  If file1 (file2) is `-', the standard input is used.	If
       file1 (file2) is a directory, then a file in that directory whose file-name is the same as the file-name of file2  (file1)  is  used.   The
       normal output contains lines of these forms:

	    n1 a n3,n4
	    n1,n2 d n3
	    n1,n2 c n3,n4

       These  lines resemble ed commands to convert file1 into file2.  The numbers after the letters pertain to file2.	In fact, by exchanging `a'
       for `d' and reading backward one may ascertain equally how to convert file2 into file1.	As in ed, identical pairs where n1 = n2 or n3 = n4
       are abbreviated as a single number.

       Following  each	of these lines come all the lines that are affected in the first file flagged by `<', then all the lines that are affected
       in the second file flagged by `>'.

       The -b option causes trailing blanks (spaces and tabs) to be ignored and other strings of blanks to compare equal.

       The -e option produces a script of a, c and d commands for the editor ed, which will recreate file2 from file1.	The -f option  produces  a
       similar	script,  not useful with ed, in the opposite order.  In connection with -e, the following shell program may help maintain multiple
       versions of a file.  Only an ancestral file ($1) and a chain of version-to-version ed scripts ($2,$3,...) made by diff need be on hand.	 A
       `latest version' appears on the standard output.

	    (shift; cat $*; echo '1,$p') | ed - $1

       Except in rare circumstances, diff finds a smallest sufficient set of file differences.

       Option  -h  does  a  fast,  half-hearted job.  It works only when changed stretches are short and well separated, but does work on files of
       unlimited length.  Options -e and -f are unavailable with -h.

FILES

       /tmp/d?????
       /usr/lib/diffh for -h

SEE ALSO

       cmp(1), comm(1), ed(1)

DIAGNOSTICS

       Exit status is 0 for no differences, 1 for some, 2 for trouble.

BUGS

       Editing scripts produced under the -e or -f option are naive about creating lines consisting of a single `.'.

																	   DIFF(1)

DIFF3(1)						      General Commands Manual							  DIFF3(1)

NAME

       diff3 - 3-way differential file comparison

SYNOPSIS

       diff3 [ -exEX3 ] file1 file2 file3

DESCRIPTION

       Diff3 compares three versions of a file, and publishes disagreeing ranges of text flagged with these codes:

       ====	       all three files differ

       ====1	       file1 is different

       ====2	       file2 is different

       ====3	       file3 is different

       The type of change suffered in converting a given range of a given file to some other is indicated in one of these ways:

       f : n1 a        Text is to be appended after line number n1 in file f, where f = 1, 2, or 3.

       f : n1 , n2 c   Text is to be changed in the range line n1 to line n2.  If n1 = n2, the range may be abbreviated to n1.

       The original contents of the range follows immediately after a c indication.  When the contents of two files are identical, the contents of
       the lower-numbered file is suppressed.

       Under the -e option, diff3 publishes a script for the editor ed that will incorporate into file1 all changes between file2 and file3,  i.e.
       the  changes  that  normally  would  be	flagged ==== and ====3.  Option -x (-3) produces a script to incorporate only changes flagged ====
       (====3).  The following command will apply the resulting script to `file1'.

		(cat script; echo '1,$p') | ed - file1

       The -E and -X are similar to -e and -x, respectively, but treat overlapping changes (i.e., changes that would be flagged with ====  in  the
       normal listing) differently.  The overlapping lines from both files will be inserted by the edit script, bracketed by "<<<<<<" and ">>>>>>"
       lines.

       For example, suppose lines 7-8 are changed in both file1 and file2.  Applying the edit script generated by the command
							      "diff3 -E file1 file2 file3"
       to file1 results in the file:

	      lines 1-6
	      of file1
	      <<<<<<< file1
	      lines 7-8
	      of file1
	      =======
	      lines 7-8
	      of file3
	      >>>>>>> file3
	      rest of file1

       The -E option is used by RCS merge(1) to insure that overlapping changes in the merged files are preserved and brought to someone's  atten-
       tion.

FILES

       /tmp/d3?????
       /usr/libexec/diff3

SEE ALSO

       diff(1)

BUGS

       Text lines that consist of a single `.' will defeat -e.

7th Edition							 October 21, 1996							  DIFF3(1)