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Diffstat (limited to 'pause/pause.c')
-rw-r--r-- | pause/pause.c | 69 |
1 files changed, 69 insertions, 0 deletions
diff --git a/pause/pause.c b/pause/pause.c new file mode 100644 index 000000000..1e363bd7a --- /dev/null +++ b/pause/pause.c @@ -0,0 +1,69 @@ +/* +Copyright 2016 The Kubernetes Authors. +Copyright 2021 The Podman 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; +} |