Add List Names Of Files With Matches as a unix til

unix/list-names-of-files-with-matches.md

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+# List Names Of Files With Matches
+
+I often use `grep` and `ag` to search for patterns in a group or directory
+of files. Generally I am interested in looking at the matching lines
+themselves. However, sometimes I just want to know the set of files that
+have matches. Both `grep` and `ag` can be told to output nothing more than
+the names of the files with matches when given the `-l` flag.
+
+This can come in particularly handy if you just want a list of files that
+can be piped (or copied) for use with another command. This eliminates all
+the extra noise.
+
+h/t Dillon Hafer