how do I loop through the results of this FIND command in my Linux shell script?

Question

I wrote the following command to list all files in and below '~' by order of file size. It seems to work fine:

find ~ -printf "%k KB %p\n" | sort -nr

Now I want to put this is a shell script and loop through the results to do more processing.

I got this to work with a simple 'ls' command:

dir="/home/myusername"
cmd='ls'
for i in `$cmd`
do
  echo $i
done

But this doesn't work:

dir="/home/myusername"
cmd='find $dir -printf "%k KB %p\n" | sort -nr'
for i in `$cmd`
do
  echo $i
done

I've also tried using escape characters in front of the double-quotes, but that didn't work either ...

dir="/home/myusername"
cmd='find $dir -printf \"%k KB %p\n\" | sort -nr'
for i in `$cmd`
do
  echo $i
done

Any ideas what I'm doing wrong?

@BroSlow hi -- thanks for the help, but that was a typo in my question -- I changed the "~" to "$dir" -- thx — , Jan 27 '14 at 00:38
No problem, also see http://stackoverflow.com/a/11366230/3076724 to fix your `find` syntax, otherwise it will break on spaces/weird characters. — Reinstate Monica Please, Jan 27 '14 at 00:38
possible duplicate of [find while loop with files containing spaces in bash](http://stackoverflow.com/questions/11366184/find-while-loop-with-files-containing-spaces-in-bash) — that other guy, Jan 27 '14 at 00:41
@thatotherguy thanks, but I don't think it's the same issue. I'm just trying to run the admitted tricky command and the escape characters aren't working — , Jan 27 '14 at 00:53
@RobertHume The escape characters aren't working because your approach is fundamentally flawed. To loop over results, use the linked question's method (and `sort -z` to sort). — that other guy, Jan 27 '14 at 01:00
Part of the problem is that you're trying to put the command in a variable before executing it, and that'll fail when the command contains anything nontrivial (in this case, quotes and a pipe). See [BashFAQ #50: I'm trying to put a command in a variable, but the complex cases always fail!](http://mywiki.wooledge.org/BashFAQ/050). — Gordon Davisson, Jan 27 '14 at 02:35

score 3 · Answer 1 · answered Jan 27 '14 at 02:16

3

Try this while loop with find in BASH:

while read -r f; do
    echo "$f"
done < <(find "$dir" -printf "%k KB %p\n" | sort -nr)

answered Jan 27 '14 at 02:16

anubhava

score 2 · Answer 2 · answered Jan 27 '14 at 08:37

2

To execute simple commands, you can pipe the results of find into xargs:

find ~ -printf "%k KB %p\n" | sort -nr | xargs -l -i echo '{}'

-l: makes xargs process one line at a time.

-i: substitutes each occurrence of {} with the output of the pipe.

answered Jan 27 '14 at 08:37

Gerrit Brouwer

score 0 · Answer 3 · edited May 23 '17 at 12:06

0

This should work (see https://stackoverflow.com/a/11366230/3076724 for an explanation of why not to use original syntax)

find "$dir" -printf "%k KB %p\n" | sort -nr |  while read -r i; do
  echo "$i"
done

edited May 23 '17 at 12:06

Community

answered Jan 27 '14 at 01:06

@RobertHume You're definitely running it as a bash script? – Reinstate Monica Please Jan 27 '14 at 01:13
I think so -- how can I be 100% certain? – Jan 27 '14 at 01:19
1

@RobertHume Put `ps -o cmd= -p $$` inside the script. Or just `echo $0 `from your shell before you run it to see what shell you're using, or just run it as `bash whateverscript` – Reinstate Monica Please Jan 27 '14 at 01:26
1

Isn't the default delimiter of `while read` syntax a newline character? – anishsane Jan 27 '14 at 06:15

3 Answers3