bash to batch rename files with adding numbers

Question

I have a bunch of .jpg files with random names. I want a bash script to rename them like this:

basename-0.jpg
basename-1.jpg
basename-2.jpg
.
.
.
.
basename-1000.jpg

I wrote this:

n = 0;
for file in *.jpg ; do mv  "${file}" basename"${n}".jpg; n+=1;  done

But the problem with the above bash is that in the loop, n is considered as string so n+1 just adds another '1' to the end of newly moved file. Appreciate your hints.

score 14 · Accepted Answer · answered Oct 19 '13 at 16:16

14

Use $((expression)) for arithmetic expansion in bash shell

n=0;
for file in *.jpg ; do mv  "${file}" basename"${n}".jpg; n=$((n+1));  done

answered Oct 19 '13 at 16:16

Yann Moisan

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How would you do adapt this answer for the case where you don't know the file extension ahead of time? Like say I have a directory of mixed extensions (that I don't know ahead of time) and I want to blindly name them all with an incrementing pattern, but keep their existing extension type. – Raleigh L. Sep 13 '22 at 05:52

score 4 · Answer 2 · answered Oct 19 '13 at 18:55

4

Bash can also pre/post increment/decrement variable values using arithmetic evaluation syntax like ((var++)).

n=0;
for file in *.jpg ; do mv  "${file}" basename"${n}".jpg; ((n++));  done

answered Oct 19 '13 at 18:55

John B

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AsymLabs · Answer 3 · 2013-10-19T18:52:34.190

3

Did you want 'basename' or $(basename)? More generalized forms are:

# create basename-0.jpg, basename-1.jpg, ... basename-n.jpg
e='jpg'; j=0; for f in *.$e; do mv "$f" basename-$((j++)).$e; done

or

# preserve stem: <stemA>-0.jpg, <stemB>-1.jpg, ... <stem?>-n.jpg
e='jpg'; j=0; for f in *.$e; do mv "$f" "${f%.*}"-$((j++)).$e; done

edited Oct 19 '13 at 18:52

answered Oct 19 '13 at 18:40

AsymLabs

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bash to batch rename files with adding numbers

3 Answers3