Grep Include Only *.txt

The grep command supports recursive file pattern option as follows:

grep -R "pattern" /path/to/dir

To limit your search for *.txt, try passing the --include option to grep command

Syntax and examples for --include option

The syntax is:

grep -R --include=GLOB "pattern" /path/to/dir
grep -R --include="*.txt" "pattern" /path/to/dir
grep -R --include="*.txt" "foo" ~/projects/

You can include files whose base name matches GLOB using wildcard matching. A file-name glob can use *, ?, and […] as wildcards, and \ to quote a wildcard or backslash character literally. You can ignore case distinctions in both the PATTERN and the input files with -i optoon i.e. case-insensitive search. In this following example, search for all *.py, *.pl, and *.sh files for “main” word in my /raid6/projects/sysmanagement/ directory:

grep --color -Ri --include="*.py" --include="*.sh" --include="*.pl" "main" /raid6/projects/sysmanagement/

Or

grep --color -Ri  --include=*.{py,pl,sh} "main" /raid6/projects/sysmanagement/

OR a safer option would be (note –color removed and * replaced with \*):

grep -Ri  --include=\*.{py,pl,sh} "main" /raid6/projects/sysmanagement/

The --include option provides you the following advantages:

1. Speed up the search.
2. Only match given file pattern.
3. Do not search for binary files such as compiled files or image files. In other words only look for *.txt or *.py file patterns and so on.