So this behavior of `bash`s seems like a bug to me. I stumbled across it by
accident.
>From within a stack of x3 functions called from a case within a for loop,
when trying to assign a value to a read-only variable, `printf` and `read`
both fail with exit codes of 1, and the functions, `case` and `for`
commands all complete. When trying effectively the same thing with a
simple assignment syntax, `x=z`, when the assignment fails, the functions
return, `case` fails to complete and `for` returns an exit code of 1.
It's probably a pretty rare use case, though. I tried this out on Android
12 on a Nokia in Termux and Fedora 38 on an HP in XFCE; that's all I've got
for the time being. There isn't any pressing need to look into this one;
I'm just curious. A reproducer's attached.
Thanks & Happy summer,
Wiley
###
$ cat ro-var-in-fn.sh
#!/bin/bash -x
reset
readonly x=y
declare -p x SHELLOPTS BASHOPTS
: "hyphen: $-"
a(){ : go a; b $1; : end a;}
b(){ : go b; c $1; : end b;}
c(){
: go c
declare -p x
case "$1" in
1 )
false
: "exit, false: $?"
;;
2 )
printf -v x '%s' $1
: "exit, printf: $?"
;;
3 )
read -r x <<< $1
: "exit, read: $?"
;;
4 )
x=$1
: "exit, var assignment: $?"
;;
5 )
echo $1
;;
esac
: "exit, case: $?"
: end c
}
declare -pf a b c
for ii in {1..5}
do
a $ii
: "exit, a $ii: $?"
done
: "exit, for loop: $?"
###
