How can I pass a complete argument list in bash while keeping mulitword arguments together?

I am having some issues with word-splitting in bash variable expansion. I want to be able to store an argument list in a variable and run it, but any quoted multiword arguments aren't evaluating how I expected them to.

I'll explain my problem with an example. Lets say I had a function decho that printed each positional parameter on it's own line:

#!/bin/bash -u
while [ $# -gt 0 ]; do
  echo $1
  shift
done

Ok, if I go decho a b "c d" I get:

[~]$ decho a b "c d"
a
b
c d

Which is what I expect and want. But on the other hand if I get the arguments list from a variable I get this:

[~]$ args='a b "c d"'
[~]$ decho $args
a
b
"c
d"

Which is not what I want. I can go:

[~]$ echo decho $args | bash
a
b
c d

But that seems a little clunky. Is there a better way to make the expansion of $args in decho $args be word-split the way I expected?

From stackoverflow

• Have you tried:

  for arg in "$@"
  do
          echo "arg $i:$arg:"
          let "i+=1"
  done
  

  Should yield something like:

  arg 1: a
  arg 2: c d
  

  in your case.

  Straight from memory, no guarantee :-)

  David Dean : This function performs exactly the same as decho. The problem is in calling decho, not decho itself.

• You can use:

  eval decho $args
  

• hmmm.. eval decho $args works too:

  [~]$ eval decho $args
  a
  b
  c d
  

  And I may be able to do something with bash arrays using "${array[@]}" (which works like "$@"), but then I would have to write code to load the array, which would be a pain.

• You can move the eval inside the script:

  #!/bin/bash -u
  eval set -- $*
  for i; 
  do 
    echo $i;
  done
  

  Now you can do:

  $ args='a b "c d"'
  $ decho $args
  a
  b
  c d
  

  but you'll have to quote the arguments if you pass them on the CL:

  $ decho 'a b "c d"'
  a
  b
  c d