CODEWITHSUNDEEP
bashconditional-statements
melkir
melkir

Reputation: 405

bash script with case test condition

Hi I want to simplify my script with case

echo "The file $1 is "
if [ -f $1 ] then;
  echo "an regular file"
elif [ -d $1 ] then;
  echo "a directory"
fi

by something like this

case $1 in
  [ -f $1 ])
    echo "an regular file"
    ;;
  [ -d $1 ])
    echo "a directory"
    ;;
esac

Upvotes: 0

Views: 244

Answers (2)

Martin Tournoij
Martin Tournoij

Reputation: 27852

This is not how case works, in any programmming language. In case, you have one test/expression at the top that gives a value, and depending on that value, you can do different things. The whole point of this is that you only run your test command once, and not for every elif branch.
What you want, is just if/elif with a different syntax, which is sort of pointless...

If you want to simplify it, you might be able to use stat:

case $(stat -c%F "$1") in
  directory)
     echo Directory; ;;
  regular\ file)
     echo File; ;;
esac

This has (slightly) better performance than your first example, since it only runs one external command

Bonus hint: Remember to always quote filenames, so use: [ -f "$1" ] and not [ -f $1 ]. Consider that 1) [ is just a shell command (a builtin or /bin/[, makes no real difference though), and 2) $1 may contain spaces or other whitespace...

Upvotes: 4

anubhava
anubhava

Reputation: 786349

If you really want output like regular file or directory from a given file then use stat command:

stat -c '%F' afile.txt
regular file

stat -c '%F' adirectory
directory

Upvotes: 1

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