Use grep --exclude/--include syntax to not grep through certain files
I'm looking for the string foo= in text files in a directory tree. It's on a common Linux machine, I have bash shell:
grep -ircl "foo=" *
In the directories are also many binary files which match "foo=". As these results are not relevant and slow down the search, I want grep to skip searching these files (mostly JPEG and PNG images). How would I do that?
I know there are the --exclude=PATTERN and --include=PATTERN options, but what is the pattern format? The man page of grep says:
--include=PATTERN Recurse in directories only searching file matching PATTERN.
--exclude=PATTERN Recurse in directories skip file matching PATTERN.
Searching on grep include, grep include exclude, grep exclude and variants did not find anything relevant
If there's a better way of grepping only in certain files, I'm all for it; moving the offending files is not an option. I can't search only certain directories (the directory structure is a big mess, with everything everywhere). Also, I can't install anything, so I have to do with common tools (like grep or the suggested find).
Answer
Use the shell globbing syntax:
grep pattern -r --include=\*.{cpp,h} rootdir
The syntax for --exclude is identical.
Note that the star is escaped with a backslash to prevent it from being expanded by the shell (quoting it, such as --include="*.{cpp,h}", would work just as well). Otherwise, if you had any files in the current working directory that matched the pattern, the command line would expand to something like grep pattern -r --include=foo.cpp --include=bar.h rootdir, which would only search files named foo.cpp and bar.h, which is quite likely not what you wanted.