Question

When looping recursively through folders with files containing spaces the shell script I use is of this form, copied from the internet:

    while IFS= read -r -d $'\0' file; do
      dosomethingwith "$file"        # do something with each file
    done < <(find /bar -name *foo* -print0)

I think I understand the IFS bit, but I don’t understand what the ‘< <(...)‘ characters mean. Obviously there’s some sort of piping going on here.

It’s very hard to Google "< <" or "<(", you see. I tried "angle bracket parenthesis" and "less-than parenthesis" but didn’t find anything.

Answer 1

<() is called process substitution in the manual, and is similar to a pipe but passes an argument of the form /dev/fd/63 instead of using stdin.

< reads the input from a file named on command line.

Together, these two operators function exactly like a pipe, so it could be rewritten as

find /bar -name *foo* -print0 | while read line; do
  ...
done