bash batch image resize

Question

How change this string:

find . -type f -name "*.jpg" | while read i; do convert "$i" -resize 50% "${i%%.jpg*}_tn.jpg"; done

to make tn_FILENAME.jpg files, not FILENAME_tn.jpg

Thank you!

ShellFish · Accepted Answer · 2015-04-13 05:28:24Z

2

find . -type f -name "*.jpg" | while read i; do [[ "${i##*/}" =~ ^tn_ ]] || convert "$i" -resize 50% "${i%/*}/tn_${i##*/}"; done

You mean like this?

${i%/*} is the filename stripped of everything following the last dash (so the dir in which the file is located).

/tn_ adds the tn_ prefix to the file, and

${i##*/} strips everything from the file before the last dash (so it's the filename).

Paste these three together and you get your result.

answered Apr 11, 2015 at 22:35

ShellFish

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5 Comments

yes. but i have error "convert.im6: unable to open image `tn_./sets/testl/test-123.jpg.jpg': No such file or directory @ error/blob.c/OpenBlob/2638."

Try this: "${i%/*}/tn_${i##*/}"

No problem, you need me to clarify the solution?

Add grep -v tn_* when you want to run the command again after new files in the folders.

Good point, although that grep matches any path not containing "tn".