# If you'd like to omit non-matching lines from the result; add ';d' to the end of the expression.
sed -E 's/(#EXTM3U\s+|#EXTINF:\d+,|(.*\.\w{3,4}).*\s+)//g;t' <<< "#EXTM3U
#EXTINF:419,Alice in Chains - Rotten Apple
http://192.168.101.22:80/movies/9975.mkv
#EXTINF:260,Alice in Chains - Nutshell
http://192.168.101.22:80/movies/1254.mkv
#EXTINF:255,Alice in Chains - I Stay Away
http://192.168.101.22:80/movies/1254.mkv
#EXTINF:256,Alice in Chains - No Excuses
Alice in Chains_Jar of Flies_04_No Excuses.mp3
#EXTINF:157,Alice in Chains - Whale And Wasp
Alice in Chains_Jar of Flies_05_Whale And Wasp.mp3
#EXTINF:263,Alice in Chains - Don't Follow
Alice in Chains_Jar of Flies_06_Don't Follow.mp3
#EXTINF:245,Alice in Chains - Swing On This
Alice in Chains_Jar of Flies_07_Swing On This.mp3
"
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for SED, please visit: https://www.gnu.org/software/sed/manual/html_node/The-_0022s_0022-Command.html