+#include <string.h>
+
+/**
+ * crc - routines for crc of bytes
+ *
+ * Cyclic Redundancy Check routines. These are reasonably fast
+ * checksum routines, but not suitable for cryptographic use.
+ *
+ * They are useful for simple error detection, eg. a 32-bit CRC will
+ * detect a single error burst of up to 32 bits.
+ *
+ * Example:
+ * #include <ccan/crc.h>
+ * #include <stdio.h>
+ * #include <stdlib.h>
+ *
+ * int main(int argc, char *argv[])
+ * {
+ * if (argc != 2) {
+ * fprintf(stderr, "Usage: %s <string>\n"
+ * "Prints 32 bit CRC of the string\n", argv[0]);
+ * exit(1);
+ * }
+ * printf("0x%08x\n", crc32c(argv[1], strlen(argv[1])));
+ * exit(0);
+ * }
+ *
+ * Licence: GPL (v2 or any later version)
+ * Author: Gary S. Brown, Clay Haapala
+ * Maintainer: Rusty Russell <rusty@rustcorp.com.au>
+ */
+int main(int argc, char *argv[])
+{
+ if (argc != 2)
+ return 1;
+
+ if (strcmp(argv[1], "depends") == 0) {
+ return 0;
+ }
+
+ return 1;
+}