[Solved] case statement doesn't break

Gen2ly · 2012-07-10 02:36:58

I've got a case statement writen down and I thought I knew enough about bash . For every reason I think it should be breaking but it's not, instead it's returning to the top of the loop. When I type in the terminal, I get:

# script-name d file
 Create a new directory? (y/n): n
 Select PSP VIDEO sub-directory:
1) /run/media/todd/PSP/VIDEO/Explorer/
2) /run/media/todd/PSP/VIDEO/NGC-Specials/
3) /run/media/todd/PSP/VIDEO/Other/
#? 2
 Create a new directory? (y/n):

Here's the loop:

if [ "$1" == "d" ]; then
  while true; do
    read -p " Create a new directory? (y/n): " yn
    case $yn in
      [Yy] )  read -p " Directory name (no spaces): " newdir
              vid_dir="$vid_dir"/"$newdir"
              mkdir "$vid_dir" && break ;;
      [Nn] )  printf " Select PSP VIDEO sub-directory:\n"
              select vid_sub in "$vid_dir"/*/
                do
                  vid_dir="$vid_sub"
                  test -n "$vid_dir" && break
                  echo " Select 1, 2, ..."
                done ;;
      * )     echo " Answer (y)es or (n)o."
    esac
  done
  shift
fi

Any thoughts?

Last edited by Gen2ly (2012-07-10 09:23:29)

ewaller · 2012-07-10 02:41:31

My Bash is not the greatest, but don't the break's break the case statement rather than the while statement?

falconindy · 2012-07-10 03:33:39

ewaller's spot on. 'break' and 'continue' only refer to the immediate loop in the execution context. You can break out of multiple loops by passing a number as an argument, i.e. 'break 2' will get you out of both the while and the case statement.

fsckd · 2012-07-10 03:55:02

close, in bash break does not work for case statements (try it, it errors). it's for while, until, for and select loops. in Gen2ly's code above entering 'y' should produce the correct behaviour and the incorrect behaviour only when entered 'n' as there is an extra select block there. the solution is as what falconindy gave, break n, where n is the number of loops to break out of.

man bash:

  break [n]
         Exit  from  within a for, while, until, or select loop.  If n is specified, break n lev‐
         els.  n must be ≥ 1.  If n is greater than the number of enclosing loops, all  enclosing
         loops are exited.  The return value is 0 unless n is not greater than or equal to 1.

Gen2ly · 2012-07-10 09:22:42

Ah, my presumption was that break would return to the head of the script (i.e. without any loops), now I know better. Actually learning this... this is a really nicely thought out. Couldn't ask for a better explanation from better people, thanks guys.

Last edited by Gen2ly (2012-07-10 09:24:14)

Arch Linux

#1 2012-07-10 02:36:58

[Solved] case statement doesn't break

#2 2012-07-10 02:41:31

Re: [Solved] case statement doesn't break

#3 2012-07-10 03:33:39

Re: [Solved] case statement doesn't break

#4 2012-07-10 03:55:02

Re: [Solved] case statement doesn't break

#5 2012-07-10 09:22:42

Re: [Solved] case statement doesn't break

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