Re: What is the best to pass an array with specially characters as command line arguments?

[Stephane CHAZELAS]

2011-11-6, 21:02(-06), Peng Yu:
[...]
> #!/usr/bin/env bash
>
> verbatim_string="  a b c ( a'b | "
>
> args="`echo \"$verbatim_string\" | sed -f quoteverb.sed`"
>
> cmd="echo $args"
> eval "$cmd"
>
> ~$ ./main.sh
> a b c ( a'b |


Either:

#! /bin/sh
verbatim_string="  a b c ( a'b | "
cmd='(set -f; IFS=" "; echo $verbatim_string)'
eval "$cmd"

($verbatim_string expanded and split at the time $cmd is
evaluated).

Or:

#! /bin/bash

verbatim_string="  a b c ( a'b | "
set -f; IFS=' '
cmd="echo $(printf '%q ' $verbatim_string)"
eval "$cmd"

($verbatim_string expanded and split and quoted initially).

(echo being a poor choice of a command for testing as it
concatenates its arguments and possibly handles "\" characters
specially under some circumstances).

By the way, does bash have any way of introducing local scope
for options, similar to zsh's

(){
  setopt localoptions noglob shwordsplit
  local IFS=' '
  args=($string)
}

Or to set the options to defaults in a local scope to be able
to write code that works whatever the context, like zsh's:

f() {
  emulate -L zsh # ensure default zsh behavior even if caller
                 # has changed some settings
  ...
}

I suppose one can add

default_settings=$(set +o)

at the start of the script, and then

f() {
  local restore_settings
  restore_settings=$(set +o)
  eval "$default_settings"
  ...
  eval "$restore_settings"
}

Or is there any more canonical way to do it?

-- 
Stephane