diff3 -- Command

Summarize differences among three files
diff3 [-ex3] file1 file2 file3

diff3 summarizes  the differences among three  text files.  Each difference
encountered is headed by one of the following separators, which categorizes
how many of the three input files differ in a given range.  The headers are
as follows

====    All of the files are different.

====n   Only the nth file differs, where n may be 1, 2, or 3.

For each set of changes marked as above, the actual change is indicated for
each file  using a notation similar  to commands to ed.  For each filen the
following is printed:

n: la   Text is to be appended after line l in filen.

n: l,mc
        The text from  line l  to line m  is to  be changed for  filen. The
        original text  from  filen  follows this  line.   If  this text  is
        identical for two of  the files, only the  latter (higher numbered)
        of the two is printed.

Options are available to print a  script of commands to ed. Option -e tells
diff3 to generate  a script that makes all changes  between file2 and file3
to file1. This script is based upon all changes flagged with the separators
==== or ====3, as described above.

The option -x prints only those changes where all three files differ, i.e.,
those flagged with ====.

The option -3 requests only those changes where file3 differs.

Example

The following command sequence produces  a script, applies it to file1, and
sends the result to the standard output.

    (diff3 -e file1 file2 file3; echo '1,$p') | ed - file1

Files

/tmp/d3*
/usr/lib/diff3

See Also

commands,
diff,
ed

Diagnostics

An  exit status  of  zero indicates  all  three files  were identical,  one
indicates differences, and two indicates some other failure.

© 2012 by Stephen A. Ness