On Tue, Sep 17, 2024 at 16:07:58 +0200, alex xmb sw ratchev wrote:
> savedifs=${IFS@A} savedifs=${savedifs:- unset -v IFS }
> str=1,2,3 IFS=, arr=( $str ) joined=${arr[*]}
> eval "$savedifs"
Using unquoted $str in an array expansion to do the splitting has a
couple drawbacks:
1) Globbing (filename expansion) is done unless you turn it off.
hobbit:~$ str=1,2,*.xml,4
hobbit:~$ IFS=, arr=( $str ); declare -p arr
declare -a arr=([0]="1" [1]="2" [2]="passwd.5.xml" [3]="4")
Workaround: set -f, but now you have an extra shell setting to
manage (do you do a set +f later, or do you wrap it in a function
and try to use "local -", or do you use a subshell, or do you simply
leave globbing disabled for the whole script...).
2) Pitfall 47 still applies.
hobbit:~$ bash
hobbit:~$ str=1,2,,4,
hobbit:~$ IFS=, arr=( $str ); declare -p arr
declare -a arr=([0]="1" [1]="2" [2]="" [3]="4")
Same workaround as all the others -- add an extra delimiter to the
end of the input string before splitting it. If there is no empty
field at the end, then the extra delimiter gets eaten. If there
is an empty field, then the extra delimiter preserves it before
being eaten.
