The trap and jobs builtins can be used to report information about traps and jobs. This works when they're called from the current shell but in a child shell the required information is usually cleared. Special hacks allow:
- trap to work with command substitution; - jobs to work with command substitution or in a pipeline. Neither works with process substitution. - Relax the test for the trap hack so it also supports pipelines. - Pass the command to be evaluated to forkshell() in evalbackcmd() so trap and jobs both work with process substitution. function old new delta forkchild 629 640 +11 argstr 1502 1496 -6 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 1/1 up/down: 11/-6) Total: 5 bytes Signed-off-by: Ron Yorston <[email protected]> --- shell/ash.c | 13 +++++++------ shell/ash_test/ash-signals/usage.right | 12 ++++++++++++ shell/ash_test/ash-signals/usage.tests | 12 ++++++++++++ 3 files changed, 31 insertions(+), 6 deletions(-) diff --git a/shell/ash.c b/shell/ash.c index 559566b58..40b921be1 100644 --- a/shell/ash.c +++ b/shell/ash.c @@ -5190,8 +5190,7 @@ forkchild(struct job *jp, union node *n, int mode) closescript(); - if (mode == FORK_NOJOB /* is it `xxx` ? */ - && n && n->type == NCMD /* is it single cmd? */ + if (n && n->type == NCMD /* is it single cmd? */ /* && n->ncmd.args->type == NARG - always true? */ && n->ncmd.args && strcmp(n->ncmd.args->narg.text, "trap") == 0 && n->ncmd.args->narg.next == NULL /* "trap" with no arguments */ @@ -5285,10 +5284,12 @@ forkchild(struct job *jp, union node *n, int mode) ) { TRACE(("Job hack\n")); /* "jobs": we do not want to clear job list for it, - * instead we remove only _its_ own_ job from job list. + * instead we remove only _its_ own_ job from job list + * (if it has one). * This makes "jobs .... | cat" more useful. */ - freejob(curjob); + if (jp) + freejob(curjob); return; } #endif @@ -6607,9 +6608,9 @@ evalbackcmd(union node *n, struct backcmd *result if (pipe(pip) < 0) ash_msg_and_raise_perror("can't create pipe"); - /* process substitution uses NULL job/node, like openhere() */ + /* process substitution uses NULL job, like openhere() */ jp = (ctl == CTLBACKQ) ? makejob(/*n,*/ 1) : NULL; - if (forkshell(jp, (ctl == CTLBACKQ) ? n : NULL, FORK_NOJOB) == 0) { + if (forkshell(jp, n, FORK_NOJOB) == 0) { /* child */ FORCE_INT_ON; close(pip[ip]); diff --git a/shell/ash_test/ash-signals/usage.right b/shell/ash_test/ash-signals/usage.right index c0dbd6c3c..df1ed2dd7 100644 --- a/shell/ash_test/ash-signals/usage.right +++ b/shell/ash_test/ash-signals/usage.right @@ -6,6 +6,18 @@ trap -- 'a' INT trap -- 'a' USR1 trap -- 'a' USR2 ___ +trap -- 'a' EXIT trap -- 'a' INT trap -- 'a' USR1 trap -- 'a' USR2 +___ +trap -- 'a' EXIT +trap -- 'a' INT +trap -- 'a' USR1 +trap -- 'a' USR2 +___ +trap -- 'a' EXIT +trap -- 'a' INT +trap -- 'a' USR1 +trap -- 'a' USR2 +___ ___ trap -- 'a' USR1 trap -- 'a' USR2 diff --git a/shell/ash_test/ash-signals/usage.tests b/shell/ash_test/ash-signals/usage.tests index d29c6e74a..34e24cceb 100755 --- a/shell/ash_test/ash-signals/usage.tests +++ b/shell/ash_test/ash-signals/usage.tests @@ -10,6 +10,18 @@ trap "a" EXIT INT USR1 USR2 echo ___ trap +# show them by command substitution +echo ___ +echo $(trap) + +# show them by pipe +echo ___ +trap | cat + +# show them by process substitution +echo ___ +cat <(trap) + # clear one echo ___ trap 0 INT -- 2.39.2 _______________________________________________ busybox mailing list [email protected] http://lists.busybox.net/mailman/listinfo/busybox
