Simple Unix way of looping through space-delimited strings?

Question

I have a file, called file_list, containing space-delimited strings, each of which is a file name of a file to be processed. I now wish to loop through all the file names and process them one by one. Pseudocode is

for every filename in file_list
    process(filename);
end

I have come up with a rather clumsy solution, which is

1. load the file into a variable by filenames='cat file_list'
2. count the number of spaces, N, by tr -cd ' ' <temp_list | wc -c
3. loop from 1 to N and parse by space each file name out with cut

Is there an easier/more elegant way of doing this?

Answer 1

The easiest way to do it is a classic trick that's been in the bourne shell for a while.

for filename in `cat file_list`; do
  # Do stuff here
done

Answer 2

You can change the file to have words be line separated instead of space separated. This way, you can use the typical syntax:

while read line
do
   do things with $line
done < file

With tr ' ' '\n' < file you replace spaces with new lines, so that this should make:

while read line
do
   do things with $line
done < <(tr ' ' '\n' < file)

Test

$ cat a
hello this is a set of strings
$ while read line; do echo "line --> $line"; done < <(tr ' ' '\n' < a)
line --> hello
line --> this
line --> is
line --> a
line --> set
line --> of
line --> strings