diff options
Diffstat (limited to 'bin/sh')
| -rw-r--r-- | bin/sh/trap.c | 156 |
1 files changed, 107 insertions, 49 deletions
diff --git a/bin/sh/trap.c b/bin/sh/trap.c index 5b99d42..7fe98a3 100644 --- a/bin/sh/trap.c +++ b/bin/sh/trap.c @@ -33,7 +33,7 @@ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF * SUCH DAMAGE. * - * $Id: trap.c,v 1.4 1996/09/01 10:21:47 peter Exp $ + * $Id: trap.c,v 1.5 1996/12/14 06:19:32 steve Exp $ */ #ifndef lint @@ -72,43 +72,99 @@ static char const sccsid[] = "@(#)trap.c 8.5 (Berkeley) 6/5/95"; #define S_RESET 5 /* temporary - to reset a hard ignored sig */ -extern char nullstr[1]; /* null string */ - -char *trap[NSIG+1]; /* trap handler commands */ MKINIT char sigmode[NSIG]; /* current value of signal */ -char gotsig[NSIG]; /* indicates specified signal received */ int pendingsigs; /* indicates some signal received */ +static char *trap[NSIG]; /* trap handler commands */ +static char gotsig[NSIG]; /* indicates specified signal received */ +static int ignore_sigchld; /* Used while handling SIGCHLD traps. */ static int getsigaction __P((int, sig_t *)); + /* - * The trap builtin. + * Map a string to a signal number. */ +static int +sigstring_to_signum(sig) + char *sig; +{ + + if (is_number(sig)) { + int signo; + + signo = atoi(sig); + return ((signo >= 0 && signo < NSIG) ? signo : (-1)); + } else if (strcasecmp(sig, "exit") == 0) { + return (0); + } else { + int n; + + if (strncasecmp(sig, "sig", 3) == 0) + sig += 3; + for (n = 1; n < NSIG; n++) + if (strcasecmp(sys_signame[n], sig) == 0) + return (n); + } + return (-1); +} + +/* + * Print a list of valid signal names. + */ +static void +printsignals() +{ + int n; + + for (n = 1; n < NSIG; n++) { + out1fmt("%s", sys_signame[n]); + if (n == (NSIG / 2) || n == (NSIG - 1)) + out1str("\n"); + else + out1c(' '); + } +} + + +/* + * The trap builtin. + */ int trapcmd(argc, argv) int argc; char **argv; { char *action; - char **ap; int signo; if (argc <= 1) { - for (signo = 0 ; signo <= NSIG ; signo++) { + for (signo = 0 ; signo < NSIG ; signo++) { if (trap[signo] != NULL) - out1fmt("%d: %s\n", signo, trap[signo]); + out1fmt("trap -- '%s' %s\n", trap[signo], + (signo) ? sys_signame[signo] : "exit"); } return 0; } - ap = argv + 1; - if (is_number(*ap)) - action = NULL; - else - action = *ap++; - while (*ap) { - if ((signo = number(*ap)) < 0 || signo > NSIG) - error("%s: bad trap", *ap); + action = NULL; + if (*++argv && strcmp(*argv, "--") == 0) + argv++; + if (*argv && sigstring_to_signum(*argv) == -1) { + if ((*argv)[0] != '-') { + action = *argv; + argv++; + } else if ((*argv)[1] == '\0') { + argv++; + } else if ((*argv)[1] == 'l' && (*argv)[2] == '\0') { + printsignals(); + return 0; + } else { + error("bad option %s", *argv); + } + } + while (*argv) { + if ((signo = sigstring_to_signum(*argv)) == -1) + error("bad signal %s", *argv); INTOFF; if (action) action = savestr(action); @@ -118,22 +174,21 @@ trapcmd(argc, argv) if (signo != 0) setsignal(signo); INTON; - ap++; + argv++; } return 0; } - /* * Clear traps on a fork. */ - void -clear_traps() { +clear_traps() +{ char **tp; - for (tp = trap ; tp <= &trap[NSIG] ; tp++) { + for (tp = trap ; tp <= &trap[NSIG - 1] ; tp++) { if (*tp && **tp) { /* trap not NULL or SIG_IGN */ INTOFF; ckfree(*tp); @@ -146,12 +201,10 @@ clear_traps() { } - /* * Set the signal handler for the specified signal. The routine figures * out what it should be set to. */ - long setsignal(signo) int signo; @@ -159,7 +212,6 @@ setsignal(signo) int action; sig_t sigact = SIG_DFL; char *t; - extern void onsig(); if ((t = trap[signo]) == NULL) action = S_DFL; @@ -197,7 +249,7 @@ setsignal(signo) } } - t = &sigmode[signo - 1]; + t = &sigmode[signo]; if (*t == 0) { /* * current setting unknown @@ -231,6 +283,7 @@ setsignal(signo) return (long)signal(signo, sigact); } + /* * Return the current setting for sig w/o changing it. */ @@ -247,18 +300,19 @@ getsigaction(signo, sigact) return 1; } + /* * Ignore a signal. */ - void ignoresig(signo) int signo; { - if (sigmode[signo - 1] != S_IGN && sigmode[signo - 1] != S_HARD_IGN) { + + if (sigmode[signo] != S_IGN && sigmode[signo] != S_HARD_IGN) { signal(signo, SIG_IGN); } - sigmode[signo - 1] = S_HARD_IGN; + sigmode[signo] = S_HARD_IGN; } @@ -278,59 +332,65 @@ SHELLPROC { #endif - /* * Signal handler. */ - void onsig(signo) int signo; { + signal(signo, onsig); if (signo == SIGINT && trap[SIGINT] == NULL) { onint(); return; } - gotsig[signo - 1] = 1; + if (signo != SIGCHLD || !ignore_sigchld) + gotsig[signo] = 1; pendingsigs++; } - /* * Called to execute a trap. Perhaps we should avoid entering new trap * handlers while we are executing a trap handler. */ - void -dotrap() { +dotrap() +{ int i; int savestatus; for (;;) { - for (i = 1 ; ; i++) { - if (gotsig[i - 1]) + for (i = 1; i < NSIG; i++) { + if (gotsig[i]) { + gotsig[i] = 0; + if (trap[i]) { + /* + * Ignore SIGCHLD to avoid infinite recursion + * if the trap action does a fork. + */ + if (i == SIGCHLD) + ignore_sigchld++; + savestatus = exitstatus; + evalstring(trap[i]); + exitstatus = savestatus; + if (i == SIGCHLD) + ignore_sigchld--; + } break; - if (i >= NSIG) - goto done; + } } - gotsig[i - 1] = 0; - savestatus=exitstatus; - evalstring(trap[i]); - exitstatus=savestatus; + if (i >= NSIG) + break; } -done: pendingsigs = 0; } - /* * Controls whether the shell is interactive or not. */ - - void setinteractive(on) int on; @@ -346,11 +406,9 @@ setinteractive(on) } - /* * Called to exit the shell. */ - void exitshell(status) int status; |
