this post was submitted on 11 Aug 2024
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[โ€“] needanke 1 points 3 months ago* (last edited 3 months ago) (1 children)

can anyone help me figure out, why the following shell script does not work:

#!/bin/bash
while IFS= read -d $'\0' -r "dir" ; do 
      dir=${dir:2};
      echo "${dir}"\#;
      cd "'""${dir}""'" ;
      ls;
      ##doing something else
     # cd  ..;
done < <(find ./  -mindepth 1 -maxdepth 1 -type d -print0)

I am running it in a location with a lots of folders containing spaces (think of it like this:

/location containing spaces# ls
'foo ba' 'baa foo ' 'tee pot'

I get errors of the following form:

script.sh: line 5: cd: 'baa foo ': No such file or directory

but when I manually enter cd 'baa foo' it works fine. Why could that be? (the echo retuns something like "foo baa #" .) It really confuses me that the cd with the exact same string works when I enter it manually. I have allready tried leaving out the quotes in the cd command and escaping the spaces using dir=$(printf %q "${dir}"); before the cd but that did not work either.

tbh I am new to shell scripts so maybe there is something obvious I overlooked.

[โ€“] anzo@programming.dev 1 points 3 months ago

You're probably over-complicating things. Have you heard about the find -print0 | xargs -0 idiom? all that variable interpolation (dir=${dir:2}) and quoting "'""${dir}""'" is better to be dealt by the built-in shell tools. Or you could write a script for the whole body of that while loop, and then call find . -exec ./action.sh {} \;. Same script could be used with the previously mentioned idiom too, you'd need to use bash -c ./action.sh though. One advantage of "find | xargs" is that you can run these concurrently, paralellizing the action to all your dirs, in groups, of say 4 of them... and so on... it's cool and simple.