Matching and printing regex groups in sed
Overview
A CLI one-liner using regular expressions and sed to capture a group of information and print it. I typically use python to build complex regular expression pattern matching and grouping. In this example, a simple one-liner pulls data out of a text file.
Details
The input file is a list of Markdown links:
jemurray@jasons-mbp:~ $ head -1 scratch.txt
[Schedule requirements gathering meeting for WSA](https://example.com)
The sed command pulls all the text between the square-brackets [...].
-n- Surpasses output; by default,sedprints all data after a match is made.s- Search\[- Match a left-bracket\(- Start the group match.*- Match anything up to the next more specific match character\)- End the group match (this group match will be printed to the console)\](.*$- Match the right-bracket, left-parentheses, and any text to the end of the line./\1/- print the information stored in the first group match()p- print the match
jemurray@jasons-mbp:~ $ cat scratch.txt | sed -n "s/\[\(.*\)\](.*$/\1/p" | head -1
Schedule requirements gathering meeting for WSA
I love the command line!