source moved

1 files changed, 150 insertions, 0 deletions

diff --git a/rpt.c b/rpt.c
new file mode 100644
index 0000000..1a9a256
--- /dev/null
+++ b/rpt.c
@@ -0,0 +1,150 @@
+#define _GNU_SOURCE		/* getopt_long */
+
+#include <getopt.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <sys/wait.h>
+#include <unistd.h>
+
+#define VERSION "1.0.0"
+
+void
+print_usage(FILE *output)
+{
+	fprintf(output, "Usage:\n");
+	fprintf(output, "rpt [-n | --count COUNT] [-f | --force] COMMAND\n");
+	fprintf(output, "rpt [-h | --help]\n");
+	fprintf(output, "rpt [-V | --version]\n");
+}
+
+void
+print_help()
+{
+	puts("Repeat : repeat a shell command");
+	puts("");
+	print_usage(stdout);
+}
+
+void
+print_version()
+{
+	puts(VERSION);
+}
+
+/* Exit whenever a subprocess fails. */
+void
+exit_on_error(int status)
+{
+	if (WIFEXITED(status))
+		return;
+
+	fprintf(stderr, "Process exited with status %d, aborting.\n", status);
+	exit(1);
+}
+
+/* Ignore subprocesses' errors. */
+void
+continue_on_error(int status)
+{
+	(void) status;
+}
+
+/* Invoke the executable *ARGV COUNT times, passing it the rest of ARG as
+   arguments. Call HANDLE_ERROR_F between each process. */
+void
+repeat_cmd(char **argv, long count, void (*handle_error_f)(int))
+{
+	pid_t pid;
+	int status;
+
+	for(long i = 0; i < count; ++i)
+	{
+		pid = fork();
+
+		if (pid == 0)
+		{
+			/* child */
+			status = execvp(argv[0], argv);
+
+			if (status < 0)
+				exit(1);
+
+			exit(2);
+		}
+		else
+		{
+			/* parent */
+			int exit_status = 0;
+
+			waitpid(pid, &exit_status, 0);
+
+			handle_error_f(exit_status);
+		}
+	}
+}
+
+int
+main(int argc, char* argv[])
+{
+	struct option const opts[] = {
+		{"count", required_argument, NULL, 'n'},
+		{"force", no_argument, NULL, 'f'},
+		{"version", no_argument, NULL, 'V'},
+		{"help", no_argument, NULL, 'h'},
+		{NULL, 0, NULL, 0}
+	};
+
+	opterr = 0;		/* dismiss getopt error message */
+	int opt;
+
+	char *strcount = NULL;
+	long count = 1;
+
+	void (*handle_error_f)(int status) = exit_on_error;
+
+	while ((opt = getopt_long(argc, argv, "+:n:fVh", opts, NULL)) >= 0)
+	{
+		switch(opt)
+		{
+		case 'n':
+			strcount = optarg;
+			break;
+		case 'f':
+			handle_error_f = continue_on_error;
+			break;
+		case 'h':
+			print_help();
+			return 0;
+		case 'V':
+			print_version();
+			return 0;
+		case ':':
+			fprintf(stderr, "COUNT value missing.\n");
+			print_usage(stderr);
+			return 1; /* invalid option */
+		default:
+			print_usage(stderr);
+			return 1; /* invalid option */
+		}
+	}
+
+	if (strcount)
+	{
+		char *err = NULL;
+		count = strtol(strcount, &err, 10);
+
+		if (err && (*err != '\0'))
+		{
+			fprintf(stderr, "Failed to read COUNT : '%s'.\n",
+				strcount);
+			return 2; /* error while reading COUNT */
+		}
+	}
+
+	if (optind >= argc)
+		return 3;	/* COMMAND not provided */
+
+	repeat_cmd(argv + optind, count, handle_error_f);
+
+	return 0;
+}