A two step file rename

Question

I'd like to combine two parts of code into a script that can me used to batch rename files. So far, I got this far:

file name before: 12345-[name]_ABC_12345.txt

file name after: name

for f in *.txt;  do 
    mv "$f" "${f//]*}";
done

for f in *txt;  do 
    echo mv "$f" "${f/*[/}";
done

Answer 1

Assuming I understand your requirement correctly, you seem to be looking for

for f in *\[*\]*.txt; do
    head=${f%%\]*}
    mv "$f" "${head#*\[}"
done

This will extract the part between the first pair of square brackets and use that as the destination name. ${var#head} and ${var%tail} return the value of $var with any prefix matching the glob expression head, or any suffix matching tail, respectively, trimmed off. The double-operator variants trim the longest instead of the shortest match.