+#include <stdio.h>
+#include <string.h>
+#include "config.h"
+
+/**
+ * foreach - macro for simple iteration of arrays
+ *
+ * The foreach_int and foreach_ptr macros allow simple iteration of
+ * static arrays. This is very efficient with good compiler support
+ * (ie. gcc), and not too bad (ie. a few compares and mallocs) for
+ * other compilers.
+ *
+ * License: LGPL (3 or any later version)
+ * Author: Rusty Russell <rusty@rustcorp.com.au>
+ *
+ * Example:
+ * // Figure out how to get usage: message out of a program.
+ * #include <ccan/foreach/foreach.h>
+ * #include <stdio.h>
+ * #include <stdlib.h>
+ * #include <string.h>
+ * #include <err.h>
+ *
+ * // Returns true if program outputs "usage:"
+ * static bool try_usage(const char *prog, const char *arg)
+ * {
+ * char *command;
+ * FILE *in;
+ * int status;
+ *
+ * command = malloc(strlen(prog) + 1 + strlen(arg) + 1 +
+ * sizeof("</dev/null 2>&1 | grep -qiw usage:"));
+ * sprintf(command, "%s %s </dev/null 2>&1 | grep -qiw usage:",
+ * prog, arg);
+ * in = popen(command, "r");
+ * if (!in)
+ * err(2, "running '%s'", command);
+ * status = pclose(in);
+ * free(command);
+ * return (WIFEXITED(status) && WEXITSTATUS(status) == 0);
+ * }
+ *
+ * int main(int argc, char *argv[])
+ * {
+ * const char *arg;
+ *
+ * if (argc != 2)
+ * errx(1, "Usage: %s <progname>\n"
+ * "Figures out how to get usage message", argv[0]);
+ * foreach_ptr(arg, "--help", "-h", "--usage", "-?", "") {
+ * if (try_usage(argv[1], arg)) {
+ * printf("%s %s\n", argv[1], arg);
+ * exit(0);
+ * }
+ * }
+ * printf("%s is unhelpful\n", argv[1]);
+ * exit(1);
+ * }
+ */
+int main(int argc, char *argv[])
+{
+ if (argc != 2)
+ return 1;
+
+ if (strcmp(argv[1], "depends") == 0) {
+ return 0;
+ }
+
+ return 1;
+}