This directory contains the GNU diff, diff3, sdiff, and cmp utilities.
Their features are a superset of the Unix features and they are
significantly faster.  cmp has been moved here from the GNU textutils.

Computer users often find occasion to ask how two files differ.
Perhaps one file is a newer version of the other file.  Or maybe the
two files started out as identical copies but were changed by
different people.

You can use the diff command to show differences between two files, or
each corresponding file in two directories.  diff outputs differences
between files line by line in any of several formats, selectable by
command line options.  This set of differences is often called a diff
or patch.  For files that are identical, diff normally produces no
output; for binary (non-text) files, diff normally reports only that
they are different.

You can use the cmp command to show the offsets and line numbers where
two files differ.  Cmp can also show all the characters that differ
between the two files, side by side.

You can use the diff3 command to show differences among three files.
When two people have made independent changes to a common original,
diff3 can report the differences between the original and the two
changed versions, and can produce a merged file that contains both
persons' changes together with warnings about conflicts.

You can use the sdiff command to merge two files interactively.

You can use the set of differences produced by diff to distribute
updates to text files (such as program source code) to other people.
This method is especially useful when the differences are small
compared to the complete files.  Given diff output, you can use the
patch program to update, or patch, a copy of the file.  If you think
of diff as subtracting one file from another to produce their
difference, you can think of patch as adding the difference to one
file to reproduce the other.

 PERMSSN    UID  GID    PACKED    SIZE  RATIO     CRC       STAMP          NAME
---------- ----------- ------- ------- ------ ---------- ------------ -------------
-rw-rw-r-- 20025/200    384990 1146880  33.6% -lh5- 0b5e Mar 30  1998 diffutils-2.7-bin.tar
---------- ----------- ------- ------- ------ ---------- ------------ -------------
 Total         1 file   384990 1146880  33.6%            Mar 16  1998