I have this test variable in ZSH:
test_str='echo "a \" b c"'
I'd like to parse this into an array of two strings ("echo" "a \" b c").
i.e. Read test_str as the shell itself would and give me back an array of
arguments.
Please note that I'm not looking to split on white space or anything like that. This is really about parsing arbitrarily complex strings into shell arguments.
Zsh has (z) modifier:
ARGS=( ${(z)test_str} )
. But this will produce echo and "a \" b c", it won’t unquote string. To unquote you have to use Q modifier:
ARGS=( ${(Q)${(z)test_str}} )
: results in having echo and a " b c in $ARGS array. Neither would execute code in …$(…), but (z) will split $(false true) into one argument.
that is to say:
% testfoo=${(z):-'blah $(false true)'}; echo $testfoo[2]
$(false true)
(z) was the key. Thanks. I also added an example of what I think you meant with your last point.
$(false true) as an example? Is it a convention or arbitrary / for the lack of a better command?
false in zsh is silent even in case false --help, it will not produce help like /bin/false --help from binutils does). Not a convention I know about, but using false or true commands with any arguments is safe, with the addition that specifically false command may fail a script depending on settings (like set -e).A simpler (?) answer is hinted at by the wording of the question. To set shell argument, use set:
#!/bin/sh
test_str='echo "a \" b"'
eval set $test_str
for i; do echo $i; done
This sets $1 to echo and $2 to a " b. eval certainly has risks, but this is portable sh. It does not assign to an array, of course, but you can use $@ in the normal way.
eval set - $test_str will prevent anything in $test_str being interpreted as the usual args to set