 <p>Try this</p> <pre><code>(\w+\.\w+) </code></pre> <p><a href="https://regex101.com/r/wK3cK7/1" rel="nofollow">https://regex101.com/r/wK3cK7/1</a></p> <p>Output:</p> <pre><code>MATCH 1 1. [13-26] `summary_t.dat` MATCH 2 1. [33-48] `pre_summary.csv` MATCH 3 1. [50-58] `data.dat` </code></pre>