| /* |
| Copyright 2016 The Kubernetes Authors. |
| |
| Licensed under the Apache License, Version 2.0 (the "License"); |
| you may not use this file except in compliance with the License. |
| You may obtain a copy of the License at |
| |
| http://www.apache.org/licenses/LICENSE-2.0 |
| |
| Unless required by applicable law or agreed to in writing, software |
| distributed under the License is distributed on an "AS IS" BASIS, |
| WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| See the License for the specific language governing permissions and |
| limitations under the License. |
| */ |
| |
| #include <signal.h> |
| #include <stdio.h> |
| #include <stdlib.h> |
| #include <string.h> |
| #include <sys/types.h> |
| #include <sys/wait.h> |
| #include <unistd.h> |
| |
| #define STRINGIFY(x) #x |
| #define VERSION_STRING(x) STRINGIFY(x) |
| |
| #ifndef VERSION |
| #define VERSION HEAD |
| #endif |
| |
| static void sigdown(int signo) { |
| psignal(signo, "Shutting down, got signal"); |
| exit(0); |
| } |
| |
| static void sigreap(int signo) { |
| while (waitpid(-1, NULL, WNOHANG) > 0) |
| ; |
| } |
| |
| int main(int argc, char **argv) { |
| int i; |
| for (i = 1; i < argc; ++i) { |
| if (!strcasecmp(argv[i], "-v")) { |
| printf("pause.c %s\n", VERSION_STRING(VERSION)); |
| return 0; |
| } |
| } |
| |
| if (getpid() != 1) |
| /* Not an error because pause sees use outside of infra containers. */ |
| fprintf(stderr, "Warning: pause should be the first process\n"); |
| |
| if (sigaction(SIGINT, &(struct sigaction){.sa_handler = sigdown}, NULL) < 0) |
| return 1; |
| if (sigaction(SIGTERM, &(struct sigaction){.sa_handler = sigdown}, NULL) < 0) |
| return 2; |
| if (sigaction(SIGCHLD, &(struct sigaction){.sa_handler = sigreap, |
| .sa_flags = SA_NOCLDSTOP}, |
| NULL) < 0) |
| return 3; |
| |
| for (;;) |
| pause(); |
| fprintf(stderr, "Error: infinite loop terminated\n"); |
| return 42; |
| } |