myFun1 and myFun2 below don't produce the same output. Why?
#!/bin/bash
myFun1() {
local item
IFS=:
for item in "${@}"; do
echo "->${item}<-"
done
}
myFun2() {
local items="${@}";
local item
IFS=:
for item in "${items}"; do
echo "->${item}<-"
done
}
Invoking
myFun1 "a=b" "c='d 1'" "e"
produces
->a=b<-
->c='d 1'<-
->e<-
whereas
myFun2 "a=b" "c='d 1'" "e"
produces
->a=b c='d 1' e<-
This behavior is defined by POSIX, which both Bash and Zsh make an effort to adhere to.
@
Expands to the positional parameters, starting from one. When the expansion occurs within double-quotes, and where field splitting (see Field Splitting) is performed, each positional parameter shall expand as a separate field, ...
However, this behavior only applies to $@ itself. Assigning its value to another variable causes the meaning of the individual fields to be lost, and it's then treated as a single string (just as if you used $*).
I'm not certain about Zsh, but if in Bash you want to save $@ to another variable and be able to take advantage of field separation, you need to use an array.
myFun2() {
local -a items=("${@}");
local item
IFS=:
for item in "${items[@]}"; do
echo "->${item}<-"
done
}
In Bash, array expansion of the form "${array[@]}" has the same behavior as "$@".
