This is part of the Semicolon&Sons Code Diary - consisting of lessons learned on the job. You're in the bash category.
Last Updated: 2024-04-24
I had a bunch of files ending with .followers (corresponding to my various twitter accounts).
I wanted to change their endings to .txt. After Googling, I arrived at the
following formulation, which nicely demonstrates string substitution in bash:
for file in *.followers;
do;
mv $file ${file/%.followers/.txt};
done;
What does this % do specifically (${string%substring})? It deletes shortest
match of $substring from back of $string. I.e. here I had
${$file/%.followers} so it removed the .followers bit.