bashshellshuffle

Simple method to shuffle the elements of an array in BASH shell?

I can do this in PHP but am trying to work within the BASH shell. I need to take an array and then randomly shuffle the contents and dump that to somefile.txt.

So given array Heresmyarray, of elements a;b;c;d;e;f; it would produce an output file, output.txt, which would contain elements f;c;b;a;e;d;

The elements need to retain the semicolon delimiter. I've seen a number of bash shell array operations but nothing that seems even close to this simple concept. Thanks for any help or suggestions!

Solution

  • If you just want to put them into a file (use redirection > )

    $ echo "a;b;c;d;e;f;" | sed -r 's/(.[^;]*;)/ \1 /g' | tr " " "\n" | shuf | tr -d "\n"
  d;a;e;f;b;c;

$ echo "a;b;c;d;e;f;" | sed -r 's/(.[^;]*;)/ \1 /g' | tr " " "\n" | shuf | tr -d "\n" > output.txt

    If you want to put the items in array

    $ array=( $(echo "a;b;c;d;e;f;" | sed -r 's/(.[^;]*;)/ \1 /g' | tr " " "\n" | shuf | tr -d " " ) )
$ echo ${array[0]}
e;
$ echo ${array[1]}
d;
$ echo ${array[2]}
a;

    If your data has &#abcde;

    $ echo "a;&#abcde;c;d;e;f;" | sed -r 's/(.[^;]*;)/ \1 /g' | tr " " "\n" | shuf | tr -d "\n"
d;c;f;&#abcde;e;a;
$ echo "a;&#abcde;c;d;e;f;" | sed -r 's/(.[^;]*;)/ \1 /g' | tr " " "\n" | shuf | tr -d "\n"
&#abcde;f;a;c;d;e;