Looping through find results in bash [duplicate] - string

Question

This question already has answers here:
How to loop through file names returned by find?
(17 answers)
Closed 4 years ago.
I wanna loop through jpg files, using find to locate them.
The result is the full path name including ./ in front. I want to remove the replace ./ with ./newsubdir/ so I can use that as the output file name in a process, creating a modified copy of the original in newsubdir using the same folder structure.
This is what I tried.
#!/bin/bash
find . -type f -name '*jpg'
for file do
echo ${file:1}
done
However the substring extraction didn't seem to work at all. Is there a reason for that or a different way to do this. Very new to Bash.
I was going for something like this as a end result. Trying to square a bunch of pictures but keep the folder structure.
#!/bin/bash
find . -type f -name '*jpg'
for file do
convert '$file[2048x2048]' -gravity center -extent 2048x2048 "./newsubdir${file:1}"
done

Answer 1

You were close! Sticking a little closer to the original code (and thus avoiding starting more shells than necessary):
#!/bin/bash
find . -type f -name '*.jpg' -exec bash -c '
for file do
convert "$file[2048x2048]" -gravity center -extent 2048x2048 "./newsubdir${file:1}"
done
' _ {} +
...or, using your original shell and avoiding -exec entirely:
#!/bin/bash
while IFS= read -r -d '' file; do
convert "$file[2048x2048]" -gravity center -extent 2048x2048 "./newsubdir${file:1}"
done < <(find . -type f -name '*.jpg' -print0)
These patterns and more are part of UsingFind.

Answer 2

find . -type f -name '*jpg' -exec bash -c '
file=$1; convert "${file}[2048x2048]" -gravity \
center -extent 2048x2048 "./newsubdir/${file:1}"' _ {} \;
Frankly, I think you're much better off writing a script to do the conversion and just calling it with find . -type f -name '*.jpg' -exec script {} \;. Doing that will help to avoid inevitable quoting problems.