# do all of these in subshells since it's supposed to error out # first try some invalid patterns #"$THIS_SH" -c 'echo ${?}' -- this is valid as it's the same as $? "$THIS_SH" -c 'echo ${:?}' # then some funky ones # note: bash prints 1 - treats it as "length of $#"? We print 0 "$THIS_SH" -c 'echo ${#?}' # bash prints 0 "$THIS_SH" -c 'echo ${#:?}' # now some valid ones export msg_unset="unset!" export msg_null_or_unset="null or unset!" echo ==== "$THIS_SH" -c 'set --; echo _$1' "$THIS_SH" -c 'set --; echo _${1?}' "$THIS_SH" -c 'set --; echo _${1:?}' "$THIS_SH" -c 'set --; echo _${1?message1}' "$THIS_SH" -c 'set --; echo _${1:?message1}' "$THIS_SH" -c 'set --; echo _${1?$msg_unset}' "$THIS_SH" -c 'set --; echo _${1:?$msg_null_or_unset}' echo ==== "$THIS_SH" -c 'set -- aaaa; echo _$1' "$THIS_SH" -c 'set -- aaaa; echo _${1?}' "$THIS_SH" -c 'set -- aaaa; echo _${1:?}' "$THIS_SH" -c 'set -- aaaa; echo _${1?word}' "$THIS_SH" -c 'set -- aaaa; echo _${1:?word}' "$THIS_SH" -c 'set -- aaaa; echo _${1?$msg_unset}' "$THIS_SH" -c 'set -- aaaa; echo _${1:?$msg_null_or_unset}' echo ==== "$THIS_SH" -c 'unset f; echo _$f' "$THIS_SH" -c 'unset f; echo _${f?}' "$THIS_SH" -c 'unset f; echo _${f:?}' "$THIS_SH" -c 'unset f; echo _${f?message3}' "$THIS_SH" -c 'unset f; echo _${f:?message3}' "$THIS_SH" -c 'unset f; echo _${f?$msg_unset}' "$THIS_SH" -c 'unset f; echo _${f:?$msg_null_or_unset}' echo ==== "$THIS_SH" -c 'f=; echo _$f' "$THIS_SH" -c 'f=; echo _${f?}' "$THIS_SH" -c 'f=; echo _${f:?}' "$THIS_SH" -c 'f=; echo _${f?word}' "$THIS_SH" -c 'f=; echo _${f:?message4}' "$THIS_SH" -c 'f=; echo _${f?$msg_unset}' "$THIS_SH" -c 'f=; echo _${f:?$msg_null_or_unset}' echo ==== "$THIS_SH" -c 'f=fff; echo _$f' "$THIS_SH" -c 'f=fff; echo _${f?}' "$THIS_SH" -c 'f=fff; echo _${f:?}' "$THIS_SH" -c 'f=fff; echo _${f?word}' "$THIS_SH" -c 'f=fff; echo _${f:?word}' "$THIS_SH" -c 'f=fff; echo _${f?$msg_unset}' "$THIS_SH" -c 'f=fff; echo _${f:?$msg_null_or_unset}'