From: Michal Privoznik <mprivozn@redhat.com> In Bash, the following code does not do what you think it does: func() { local var=$(false) echo $? } Here, '0' is echoed even though false is designed to exit with a non-zero code. This is because in fact the last executed command is 'local' not 'false' and thus '$?' contains zero as in "yeah, the variable is successfully declared" [1]. In our libvirt-guest shell script, there are a few places like this. Now, in next commit a syntax-check rule is introduced and to keep it simple (by avoiding multi line grep) it'll deny declaring local variables and assigning their value via a subshell regardless of subsequent '$?' check. Thus, this commit may change more than necessary, strictly speaking. But in the long run, we're on the safe side. 1: https://www.shellcheck.net/wiki/SC2155 Fixes: 08071ec0f113bb1fe8dcc263cb6bf87529e8b76b Resolves: https://gitlab.com/libvirt/libvirt/-/issues/839 Signed-off-by: Michal Privoznik <mprivozn@redhat.com> --- tools/libvirt-guests.sh.in | 34 +++++++++++++++++++++++----------- 1 file changed, 23 insertions(+), 11 deletions(-) diff --git a/tools/libvirt-guests.sh.in b/tools/libvirt-guests.sh.in index f2db1282ad..f57eda66fe 100644 --- a/tools/libvirt-guests.sh.in +++ b/tools/libvirt-guests.sh.in @@ -106,7 +106,9 @@ test_connect() list_guests() { local uri="$1" local persistent="$2" - local list="$(run_virsh_c "$uri" list --uuid $persistent)" + local list= + + list="$(run_virsh_c "$uri" list --uuid $persistent)" if [ $? -ne 0 ]; then RETVAL=1 @@ -131,9 +133,10 @@ guest_name() { guest_is_on() { local uri="$1" local uuid="$2" - local id="$(run_virsh "$uri" domid "$uuid")" + local id= guest_running="false" + id="$(run_virsh "$uri" domid "$uuid")" if [ $? -ne 0 ]; then RETVAL=1 return 1 @@ -193,7 +196,8 @@ start() { eval_gettext "Resuming guests on \$uri URI..."; echo for guest in $list; do - local name="$(guest_name "$uri" "$guest")" + local name= + name="$(guest_name "$uri" "$guest")" eval_gettext "Resuming guest \$name: " if guest_is_on "$uri" "$guest"; then if "$guest_running"; then @@ -226,11 +230,13 @@ suspend_guest() { local uri="$1" local guest="$2" - local name="$(guest_name "$uri" "$guest")" - local label="$(eval_gettext "Suspending \$name: ")" + local name= + local label= local bypass= local slept=0 + name="$(guest_name "$uri" "$guest")" + label="$(eval_gettext "Suspending \$name: ")" test "x$BYPASS_CACHE" = x0 || bypass="--bypass-cache" printf '%s...\n' "$label" run_virsh "$uri" managedsave $bypass "$guest" >/dev/null & @@ -241,7 +247,8 @@ suspend_guest() slept=$(($slept + 1)) if [ $(($slept % 5)) -eq 0 ]; then - local progress="$(run_virsh_c "$uri" domjobinfo "$guest" 2>/dev/null | \ + local progress= + progress="$(run_virsh_c "$uri" domjobinfo "$guest" 2>/dev/null | \ awk '/^Data processed:/{print $3, $4}')" if [ -n "$progress" ]; then printf '%s%s\n' "$label" "$progress" @@ -260,12 +267,13 @@ shutdown_guest() { local uri="$1" local guest="$2" - local name="$(guest_name "$uri" "$guest")" + local name= local timeout="$SHUTDOWN_TIMEOUT" local check_timeout="false" local format= local slept= + name="$(guest_name "$uri" "$guest")" eval_gettext "Starting shutdown on guest: \$name" echo retval run_virsh "$uri" shutdown "$guest" >/dev/null || return @@ -312,8 +320,9 @@ shutdown_guest_async() { local uri="$1" local guest="$2" - local name="$(guest_name "$uri" "$guest")" + local name= + name="$(guest_name "$uri" "$guest")" eval_gettext "Starting shutdown on guest: \$name" echo retval run_virsh "$uri" shutdown "$guest" > /dev/null @@ -365,7 +374,8 @@ print_guests_shutdown() *" $guest "*) continue;; esac - local name="$(guest_name "$uri" "$guest")" + local name= + name="$(guest_name "$uri" "$guest")" if [ -n "$name" ]; then eval_gettext "Shutdown of guest \$name complete." echo @@ -482,7 +492,8 @@ stop() { eval_gettext "Running guests on \$uri URI: " - local list="$(list_guests "$uri")" + local list= + list="$(list_guests "$uri")" if [ $? -eq 0 ]; then local empty=true for uuid in $list; do @@ -498,7 +509,8 @@ stop() { fi if "$persistent_only"; then - local transient="$(list_guests "$uri" "--transient")" + local transient= + transient="$(list_guests "$uri" "--transient")" if [ $? -eq 0 ]; then local empty="true" local uuid= -- 2.52.0