Question

4

How to rename files with count?

rated 0 times [ 4] [ 0] / answers: 1 / hits: 5469 / 1 Year ago, thu, may 4, 2023, 11:00:12

I have a directory like this:

randomized_quad015.png

randomized_quad030.png

randomized_quad045.png

randomized_quad060.png

randomized_quad075.png

randomized_quad090.png

randomized_quad1005.png

randomized_quad1020.png

randomized_quad1035.png

randomized_quad1050.png

randomized_quad105.png

randomized_quad1065.png

randomized_quad1080.png

randomized_quad1095.png

randomized_quad1110.png

randomized_quad1125.png

randomized_quad1140.png

and I want to rename the first files adding 0 in front of number, like:

randomized_quad0015.png

But I don't know how. Some help?

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jokaned

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1 Year ago

answered 1 Year ago fectlyole · Accepted Answer

As an alternative to the various Perl-based methods in other answers, you can do this particular example, and lots of other similar ones with plain bash:

for i in randomized_quad???.png; do   

  mv $i randomized_quad0${i#randomized_quad}

done

This loops over the filenames with only three characters in the number region, and the variable expression in braces takes each filename, snips "randomized_quad" off the front (with the # operator), and adds "randomized_quad0" on the front.

Other excitingly useful operators like this include:

% - cut something off the end

/ - search and replace (/ for the first match, // for all matches)

: - for extracting substrings

A more complete list with examples is here. Also, note that these use POSIX-style regular expressions, so . will match any character, not just a "." If you want to match a ".", you should 'escape' it, with a backslash:

TestVariable1="filename.png"

TestVariable2="filename0png"



echo "${TestVariable1%.png}"

> filename



echo "${TestVariable2%.png}"

> filename



echo "${TestVariable1%.png}"

> filename



echo "${TestVariable2%.png}"

> filename0png