1#include "libc.h" 2#include <errno.h> 3#include <signal.h> 4#include <spawn.h> 5#include <stdlib.h> 6#include <sys/wait.h> 7#include <unistd.h> 8 9int system(const char* cmd) { 10 pid_t pid; 11 sigset_t old, reset; 12 struct sigaction sa = {.sa_handler = SIG_IGN}, oldint, oldquit; 13 int status = 0x7f00, ret; 14 posix_spawnattr_t attr; 15 16 if (!cmd) 17 return 1; 18 19 sigaction(SIGINT, &sa, &oldint); 20 sigaction(SIGQUIT, &sa, &oldquit); 21 sigaddset(&sa.sa_mask, SIGCHLD); 22 sigprocmask(SIG_BLOCK, &sa.sa_mask, &old); 23 24 sigemptyset(&reset); 25 if (oldint.sa_handler != SIG_IGN) 26 sigaddset(&reset, SIGINT); 27 if (oldquit.sa_handler != SIG_IGN) 28 sigaddset(&reset, SIGQUIT); 29 posix_spawnattr_init(&attr); 30 posix_spawnattr_setsigmask(&attr, &old); 31 posix_spawnattr_setsigdefault(&attr, &reset); 32 posix_spawnattr_setflags(&attr, POSIX_SPAWN_SETSIGDEF | POSIX_SPAWN_SETSIGMASK); 33 ret = posix_spawn(&pid, "/bin/sh", 0, &attr, (char* []){(char*)"sh", (char*)"-c", (char*)cmd, 0}, __environ); 34 posix_spawnattr_destroy(&attr); 35 36 if (!ret) 37 while (waitpid(pid, &status, 0) < 0 && errno == EINTR) 38 ; 39 sigaction(SIGINT, &oldint, NULL); 40 sigaction(SIGQUIT, &oldquit, NULL); 41 sigprocmask(SIG_SETMASK, &old, NULL); 42 43 if (ret) 44 errno = ret; 45 return status; 46} 47