I have a question about the diff command if I want a recursive directory diff but only for a specific file type, how to do that?
I tried using the exclude option but can only use one pattern only:
diff /destination/dir/1 /destination/dir/2 -r -x *.xml
with the command I can only exclude xml file type, even though there are files in the folder image type (png, gif, jpg), txt, php, etc.
How can I diff only certain file types?
You can specify -x more than once.
diff -x '*.foo' -x '*.bar' -x '*.baz' /destination/dir/1 /destination/dir/2
From the Comparing Directories section of info diff (on my system, I have to do info -f /usr/share/info/diff.info.gz):
To ignore some files while comparing directories, use the '-x PATTERN' or '--exclude=PATTERN' option. This option ignores any files or subdirectories whose base names match the shell pattern PATTERN. Unlike in the shell, a period at the start of the base of a file name matches a wildcard at the start of a pattern. You should enclose PATTERN in quotes so that the shell does not expand it. For example, the option -x '*.[ao]' ignores any file whose name ends with '.a' or '.o'.
This option accumulates if you specify it more than once. For example, using the options -x 'RCS' -x '*,v' ignores any file or subdirectory whose base name is 'RCS' or ends with ',v'.