1 /* 2 * Copyright (c) 2015 Cedric Hnyda <chnyda (at) suse.com> 3 * 4 * This program is free software; you can redistribute it and/or 5 * modify it under the terms of the GNU General Public License as 6 * published by the Free Software Foundation; either version 2 of 7 * the License, or (at your option) any later version. 8 * 9 * This program is distributed in the hope that it would be useful, 10 * but WITHOUT ANY WARRANTY; without even the implied warranty of 11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 12 * GNU General Public License for more details. 13 * 14 * You should have received a copy of the GNU General Public License 15 * along with this program; if not, write the Free Software Foundation, 16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 17 */ 18 19 /* 20 * Description: 21 * Write the current process in argv[1] 22 * and returns: 23 * -> 2 if fork fails with EAGAIN, 24 * -> 1 if there is another problem 25 * -> 0 if everything worked 26 */ 27 28 #include <sys/types.h> 29 #include <stdio.h> 30 #include <unistd.h> 31 #include <errno.h> 32 33 int main(int argc, char **argv) 34 { 35 FILE *f; 36 int newpid; 37 38 if (argc != 2) { 39 fprintf(stderr, "Usage: %s /cgroup/.../tasks\n", argv[0]); 40 return 1; 41 } 42 43 f = fopen(argv[1], "a"); 44 if (!f) { 45 perror("fopen failed"); 46 return 1; 47 } 48 49 fprintf(f, "%i\n", getpid()); 50 fclose(f); 51 52 newpid = fork(); 53 if (newpid == -1 && errno == EAGAIN) 54 return 2; 55 if (newpid == -1) { 56 perror("fork() failed"); 57 return 1; 58 } 59 return 0; 60 } 61
