lightning/ccan/ccan/pipecmd/_info

#include "config.h"
#include <stdio.h>
#include <string.h>

/**
 * pipecmd - code to fork and run a command in a pipe.
 *
 * This code is a classic example of how to run a command in a child, while
 * handling the case where the exec fails.
 *
 * License: CC0 (Public domain)
 * Author: Rusty Russell <rusty@rustcorp.com.au>
 *
 * Example:
 * // Outputs HELLO WORLD
 * #include <ccan/pipecmd/pipecmd.h>
 * #include <ccan/err/err.h>
 * #include <sys/types.h>
 * #include <sys/wait.h>
 * #include <unistd.h>
 * #include <ctype.h>
 *
 * // Runs ourselves with an argument, upcases output.
 * int main(int argc, char **argv)
 * {
 *	pid_t child;
 *	int outputfd, i, status;
 *	char input[12];
 *
 *	if (argc == 2) {
 *		if (write(STDOUT_FILENO, "hello world\n", 12) != 12)
 *			exit(1);
 *		exit(0);
 *	}
 *	child = pipecmd(NULL, &outputfd, NULL, argv[0], "ignoredarg", NULL);
 *	if (child < 0)
 *		err(1, "Creating child");
 *	if (read(outputfd, input, sizeof(input)) != sizeof(input))
 *		err(1, "Reading input");
 *	if (waitpid(child, &status, 0) != child)
 *		err(1, "Waiting for child");
 *	for (i = 0; i < sizeof(input); i++)
 *		printf("%c", toupper(input[i]));
 *	exit(0);
 * }
 */
int main(int argc, char *argv[])
{
	/* Expect exactly one argument */
	if (argc != 2)
		return 1;

	if (strcmp(argv[1], "depends") == 0) {
		printf("ccan/closefrom\n");
		printf("ccan/noerr\n");
		return 0;
	}

	return 1;
}