Module Name: src
Committed By: kre
Date: Thu Aug 20 23:09:56 UTC 2020
Modified Files:
src/bin/sh: eval.c trap.c
Log Message:
Be less conservative about when we do clear_traps() when we have
traps_invalid (that is, when we actually nuke the parent shell's
caught traps in a subshell). This allows more reasonable use of
"trap -p" (and similar) in subshells than existed before (and in
particular, that command can be in a function now - there can also
be several related commands like
traps=$(trap -p INT; trap -p QUIT; trap -p HUP)
A side effect of all of this is that
(eval "$(trap -p)"; ...)
now allows copying caught traps into a subshell environment, if desired.
Also att the ksh93 variant (the one not picked by POSIX as it isn't
generally as useful) of "trap -p" (but call it "trap -P" which extracts
just the trap action for named signals (giving more than one is usually
undesirable). This allows
eval "$(trap -P INT)"
to run the action for SIGINT traps, without needing to attempt to parse
the "trap -p" output.
To generate a diff of this commit:
cvs rdiff -u -r1.180 -r1.181 src/bin/sh/eval.c
cvs rdiff -u -r1.54 -r1.55 src/bin/sh/trap.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/bin/sh/eval.c
diff -u src/bin/sh/eval.c:1.180 src/bin/sh/eval.c:1.181
--- src/bin/sh/eval.c:1.180 Thu May 14 08:34:17 2020
+++ src/bin/sh/eval.c Thu Aug 20 23:09:56 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: eval.c,v 1.180 2020/05/14 08:34:17 msaitoh Exp $ */
+/* $NetBSD: eval.c,v 1.181 2020/08/20 23:09:56 kre Exp $ */
/*-
* Copyright (c) 1993
@@ -37,7 +37,7 @@
#if 0
static char sccsid[] = "@(#)eval.c 8.9 (Berkeley) 6/8/95";
#else
-__RCSID("$NetBSD: eval.c,v 1.180 2020/05/14 08:34:17 msaitoh Exp $");
+__RCSID("$NetBSD: eval.c,v 1.181 2020/08/20 23:09:56 kre Exp $");
#endif
#endif /* not lint */
@@ -280,8 +280,10 @@ evaltree(union node *n, int flags)
next = NULL;
CTRACE(DBG_EVAL, ("pid %d, evaltree(%p: %s(%d), %#x) called\n",
getpid(), n, NODETYPENAME(n->type), n->type, flags));
+ /*
if (n->type != NCMD && traps_invalid)
free_traps();
+ */
switch (n->type) {
case NSEMI:
evaltree(n->nbinary.ch1, sflags);
@@ -302,6 +304,8 @@ evaltree(union node *n, int flags)
next = n->nbinary.ch2;
break;
case NREDIR:
+ if (traps_invalid)
+ free_traps();
evalredir(n, flags);
break;
case NSUBSHELL:
@@ -309,9 +313,13 @@ evaltree(union node *n, int flags)
do_etest = !(flags & EV_TESTED);
break;
case NBACKGND:
+ if (traps_invalid)
+ free_traps();
evalsubshell(n, flags);
break;
case NIF: {
+ if (traps_invalid)
+ free_traps();
evaltree(n->nif.test, EV_TESTED);
if (nflag || evalskip)
goto out1;
@@ -325,15 +333,23 @@ evaltree(union node *n, int flags)
}
case NWHILE:
case NUNTIL:
+ if (traps_invalid)
+ free_traps();
evalloop(n, sflags);
break;
case NFOR:
+ if (traps_invalid)
+ free_traps();
evalfor(n, sflags);
break;
case NCASE:
+ if (traps_invalid)
+ free_traps();
evalcase(n, sflags);
break;
case NDEFUN:
+ if (traps_invalid)
+ free_traps();
CTRACE(DBG_EVAL, ("Defining fn %s @%d%s\n",
n->narg.text, n->narg.lineno,
fnline1 ? " LINENO=1" : ""));
@@ -350,6 +366,8 @@ evaltree(union node *n, int flags)
exitstatus = 1;
break;
case NPIPE:
+ if (traps_invalid)
+ free_traps();
evalpipe(n);
do_etest = !(flags & EV_TESTED);
break;
@@ -1043,6 +1061,10 @@ evalcommand(union node *cmd, int flgs, s
* command eval trap
* eval command trap
* without zapping the traps completely, in all other cases we do.
+ * Function calls also do not zap the traps (but commands they execute
+ * probably will) - this allows a function like
+ * trapstate() { trap -p; }
+ * called as save_traps=$(trapstate).
*
* The test here permits eval "anything" but when evalstring() comes
* back here again, the "anything" will be validated.
@@ -1055,6 +1077,7 @@ evalcommand(union node *cmd, int flgs, s
* trapcmd() takes care of doing free_traps() if it is needed there.
*/
if (traps_invalid &&
+ cmdentry.cmdtype != CMDFUNCTION &&
((cmdentry.cmdtype!=CMDSPLBLTIN && cmdentry.cmdtype!=CMDBUILTIN) ||
(cmdentry.u.bltin != trapcmd && cmdentry.u.bltin != evalcmd)))
free_traps();
Index: src/bin/sh/trap.c
diff -u src/bin/sh/trap.c:1.54 src/bin/sh/trap.c:1.55
--- src/bin/sh/trap.c:1.54 Thu Aug 20 16:15:50 2020
+++ src/bin/sh/trap.c Thu Aug 20 23:09:56 2020
@@ -1,4 +1,4 @@
-/* $NetBSD: trap.c,v 1.54 2020/08/20 16:15:50 kre Exp $ */
+/* $NetBSD: trap.c,v 1.55 2020/08/20 23:09:56 kre Exp $ */
/*-
* Copyright (c) 1991, 1993
@@ -37,7 +37,7 @@
#if 0
static char sccsid[] = "@(#)trap.c 8.5 (Berkeley) 6/5/95";
#else
-__RCSID("$NetBSD: trap.c,v 1.54 2020/08/20 16:15:50 kre Exp $");
+__RCSID("$NetBSD: trap.c,v 1.55 2020/08/20 23:09:56 kre Exp $");
#endif
#endif /* not lint */
@@ -232,6 +232,8 @@ trapcmd(int argc, char **argv)
ap = argv + 1;
CTRACE(DBG_TRAP, ("trapcmd: "));
+ if (argc == 3 && strcmp(ap[1], "--") == 0)
+ argc--;
if (argc == 2 && strcmp(*ap, "-l") == 0) {
CTRACE(DBG_TRAP, ("-l\n"));
out1str("EXIT");
@@ -253,9 +255,9 @@ trapcmd(int argc, char **argv)
traps_invalid = 0;
return 0;
}
- if (argc >= 2 && strcmp(*ap, "-p") == 0) {
- CTRACE(DBG_TRAP, ("-p "));
- printonly = 1;
+ if (argc >= 2 && (strcmp(*ap, "-p") == 0 || strcmp(*ap, "-P") == 0)) {
+ CTRACE(DBG_TRAP, ("%s ", *ap));
+ printonly = 1 + (ap[0][1] == 'p');
ap++;
argc--;
}
@@ -265,6 +267,9 @@ trapcmd(int argc, char **argv)
ap++;
}
+ if (printonly == 1 && argc < 2)
+ goto usage;
+
if (argc <= 1) {
int count;
@@ -339,8 +344,10 @@ trapcmd(int argc, char **argv)
}
if (argc < 2) { /* there must be at least 1 condition */
+ usage:
out2str("Usage: trap [-l]\n"
" trap -p [condition ...]\n"
+ " trap -P condition ...\n"
" trap action condition ...\n"
" trap N condition ...\n");
return 2;
@@ -365,12 +372,17 @@ trapcmd(int argc, char **argv)
* (action will always be "-") here, if someone
* really wants to get that particular output
*/
- out1str("trap -- ");
- if (trap[signo] == NULL)
- out1str("-");
- else
- print_quoted(trap[signo]);
- out1fmt(" %s\n", trap_signame(signo));
+ if (printonly == 1) {
+ if (trap[signo] != NULL)
+ out1fmt("%s\n", trap[signo]);
+ } else {
+ out1str("trap -- ");
+ if (trap[signo] == NULL)
+ out1str("-");
+ else
+ print_quoted(trap[signo]);
+ out1fmt(" %s\n", trap_signame(signo));
+ }
continue;
}
