Op 16-12-17 om 17:06 schreef Chet Ramey:
> On 11/24/17 3:17 AM, Martijn Dekker wrote:
>> Here's another corner-case bug with assigning $* to a variable (i.e.:
>> foo=$*). If IFS is empty, the $* expansion removes any $'\001' (^A) and
>> $'\177' (DEL) characters. If IFS contains a value, each ^A and DEL
>> character is prefixed by another $'\001'. If IFS is unset, the bug does
>> not show up at all.
>
> Thanks for the report. I'll fix this for the next version.
FWIW, here's a test script. It's POSIX compatible so you can compare
with other shells. Correct output is
soh stx etx del / soh stx etx del
for all cases.
- M.
defaultIFS=$IFS
set -o errexit -o noglob
(set -o pipefail) 2>/dev/null && set -o pipefail
teststring=$(printf '\1\2\3\177')
n=0
trim_od() {
od -a | sed -n '1 { s/^0*[[:blank:]]*//; s/[[:blank:]]*$//; p; }'
}
doTest() {
set -- "$teststring"
eval "$testcmd"
case ${IFS+s}${IFS:+n} in
( sn ) i=$(printf %s "$IFS" | trim_od) ;;
( s ) i='(null)' ;;
( '' ) i='(unset)' ;;
( * ) echo 'internal error!' >&2; exit 125 ;;
esac
printf '\n%03d: IFS = %s: %s\n' "$((n+=1))" "$i" "$testcmd"
printf %s "$*${foo+/}${foo-}" | trim_od
}
doAllTests() {
for testcmd in \
'unset -v foo; set -- ${foo=$*}' \
'unset -v foo; set -- ${foo="$*"}' \
'unset -v foo; set -- "${foo=$*}"' \
\
'foo=; set -- ${foo:=$*}' \
'foo=; set -- ${foo:="$*"}' \
'foo=; set -- "${foo:=$*}"' \
\
'unset -v foo; set -- ${foo=$@}' \
'unset -v foo; set -- ${foo="$@"}' \
'unset -v foo; set -- "${foo=$@}"' \
\
'foo=; set -- ${foo:=$@}' \
'foo=; set -- ${foo:="$@"}' \
'foo=; set -- "${foo:=$@}"'
do
doTest "$testcmd"
done
}
unset -v IFS; doAllTests
IFS=''; doAllTests
IFS='x'; doAllTests
IFS=$defaultIFS; doAllTests
