diff options
| -rw-r--r-- | lib/libc/stdlib/system.3 | 3 | ||||
| -rw-r--r-- | lib/libc/stdlib/system.c | 51 |
2 files changed, 36 insertions, 18 deletions
diff --git a/lib/libc/stdlib/system.3 b/lib/libc/stdlib/system.3 index 44aaf0c863b8..9b82e7b9e775 100644 --- a/lib/libc/stdlib/system.3 +++ b/lib/libc/stdlib/system.3 @@ -91,3 +91,6 @@ The function conforms to .St -ansiC . +and is expected to be +.St -p1003.2 +compatible. diff --git a/lib/libc/stdlib/system.c b/lib/libc/stdlib/system.c index c438f1710a78..3bae36ae4c62 100644 --- a/lib/libc/stdlib/system.c +++ b/lib/libc/stdlib/system.c @@ -42,35 +42,50 @@ static char sccsid[] = "@(#)system.c 8.1 (Berkeley) 6/4/93"; #include <stddef.h> #include <unistd.h> #include <paths.h> +#include <errno.h> -system(command) +int system(command) const char *command; { - union wait pstat; pid_t pid; - int omask; - sig_t intsave, quitsave; + int pstat; + struct sigaction ign, intact, quitact; + sigset_t newsigblock, oldsigblock; if (!command) /* just checking... */ return(1); - omask = sigblock(sigmask(SIGCHLD)); - switch(pid = vfork()) { + /* + * Ignore SIGINT and SIGQUIT, block SIGCHLD. Remember to save + * existing signal dispositions. + */ + ign.sa_handler = SIG_IGN; + (void)sigemptyset(&ign.sa_mask); + ign.sa_flags = 0; + (void)sigaction(SIGINT, &ign, &intact); + (void)sigaction(SIGQUIT, &ign, &quitact); + (void)sigemptyset(&newsigblock); + sigprocmask(SIG_BLOCK, &newsigblock, &oldsigblock); + switch(pid = fork()) { case -1: /* error */ - (void)sigsetmask(omask); - pstat.w_status = 0; - pstat.w_retcode = 127; - return(pstat.w_status); + break; case 0: /* child */ - (void)sigsetmask(omask); + /* + * Restore original signal dispositions and exec the command. + */ + (void)sigaction(SIGINT, &intact, NULL); + (void)sigaction(SIGQUIT, &quitact, NULL); + (void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL); execl(_PATH_BSHELL, "sh", "-c", command, (char *)NULL); _exit(127); + default: /* parent */ + do { + pid = waitpid(pid, &pstat, 0); + } while (pid == -1 && errno == EINTR); + break; } - intsave = signal(SIGINT, SIG_IGN); - quitsave = signal(SIGQUIT, SIG_IGN); - pid = waitpid(pid, (int *)&pstat, 0); - (void)sigsetmask(omask); - (void)signal(SIGINT, intsave); - (void)signal(SIGQUIT, quitsave); - return(pid == -1 ? -1 : pstat.w_status); + (void)sigaction(SIGINT, &intact, NULL); + (void)sigaction(SIGQUIT, &quitact, NULL); + (void)sigprocmask(SIG_SETMASK, &oldsigblock, NULL); + return(pid == -1 ? -1 : pstat); } |