The Linux Development Platform Configuring, Using, and ... - Classes

CH07.fm Page 218 Monday, October 7, 2002 9:12 PM
218 Chapter 7 • Miscellaneous Tools
Table 7-1 Common options used with the diff command (Continued)
Option
Description
-c Context output
-n RCS style of output
-r Compare directories recursively
-y Use side-by-side format
7.3.1 Other Forms of diff Utility
There are two other important forms of the diff utility. These are diff3 and sdiff.
The diff3 utility is used to compare three files and its general format is shown below.
diff3 [options] mine older yours
Suppose you and your colleague start working on a file simultaneously. The original file is
the older file. Now you have your copy of the file (the mine file) and your colleague has his own
copy of the file (the yours file). If you want to compare both of these modified copies of the file
with the original older file, diff3 is a useful tool. See man pages of the diff3 command for
more details.
Another important utility is sdiff that finds difference between two files and merges
these two files into a third file. The general format of sdiff is as follows.
sdiff –o outfile [options] file1 file2
The sdiff is useful when you want to interactively merge two files. This is the case
when two people have made changes to a source file and at some point you want to merge these
changes into a single file. The sdiff utility is interactive and it displays two files being compared
in side-by-side fashion. It stops on each difference with a % sign prompt. On this sign you
can press different characters to make a decision. Common responses on the % prompt are
shown in Table 7-2.
Table 7-2 Commands used on % prompt of sdiff
Command
Description
L
R
e l
e r
Q
Use the left side of the version
Use the right side of the version
Edit and then use the left side
Edit and use the right side
Quit