X-Git-Url: https://git.ozlabs.org/?p=ccan;a=blobdiff_plain;f=ccan%2Fcrcsync%2F_info.c;fp=ccan%2Fcrcsync%2F_info.c;h=52e2ebe2febdc65f8e0831500567edd3cb13d50c;hp=0000000000000000000000000000000000000000;hb=94ff9fc87d90173145772a41f79987988f9f0972;hpb=c6a86ac78efbec284b444876a9ea2fbbf7e48033

diff --git a/ccan/crcsync/_info.c b/ccan/crcsync/_info.c
new file mode 100644
index 00000000..52e2ebe2
--- /dev/null
+++ b/ccan/crcsync/_info.c
@@ -0,0 +1,83 @@
+#include <stdio.h>
+#include <string.h>
+#include "config.h"
+
+/**
+ * crcsync - routines to use crc for an rsync-like protocol.
+ *
+ * This is a complete library for synchronization using a variant of the
+ * rsync protocol.
+ *
+ * Example:
+ *	// Calculate checksums of file (3-arg mode)
+ *	// Or print differences between file and checksums (4+ arg mode)
+ *	#include <ccan/crcsync/crcsync.h>
+ *	#include <ccan/grab_file/grab_file.h>
+ *	#include <stdio.h>
+ *	#include <stdlib.h>
+ *	#include <err.h>
+ *	
+ *	static void print_result(long result)
+ *	{
+ *		if (result < 0)
+ *			printf("MATCHED CRC %lu\n", -result - 1);
+ *		else if (result > 0)
+ *			printf("%lu literal bytes\n", result);
+ *	}
+ *	
+ *	int main(int argc, char *argv[])
+ *	{
+ *		size_t len, used, blocksize;
+ *		char *file;
+ *		struct crc_context *ctx;
+ *		uint32_t *crcs;
+ *		long res, i;
+ *	
+ *		if (argc < 3 || (blocksize = atoi(argv[1])) == 0)
+ *			errx(1, "Usage: %s <blocksize> <file> <crc>...\n"
+ *			     "OR: %s <blocksize> <file>", argv[0], argv[0]);
+ *	
+ *		file = grab_file(NULL, argv[2], &len);
+ *		if (!file)
+ *			err(1, "Opening file %s", argv[2]);
+ *	
+ *		if (argc == 3) {
+ *			// Short form prints CRCs of file for use in long form.
+ *			used = (len + blocksize - 1) / blocksize;
+ *			crcs = malloc(used * sizeof(uint32_t));
+ *			crc_of_blocks(file, len, blocksize, 32, crcs);
+ *			for (i = 0; i < used; i++)
+ *				printf("%i ", crcs[i]);
+ *			printf("\n");
+ *			return 0;
+ *		}
+ *	
+ *		crcs = malloc((argc - 3) * sizeof(uint32_t));
+ *		for (i = 0; i < argc-3; i++)
+ *			crcs[i] = atoi(argv[3+i]);
+ *	
+ *		ctx = crc_context_new(blocksize, 32, crcs, argc-3);
+ *		for (used = 0; used < len; ) {
+ *			used += crc_read_block(ctx, &res, file+used, len-used);
+ *			print_result(res);
+ *		}
+ *		while ((res = crc_read_flush(ctx)) != 0)
+ *			print_result(res);
+ *	
+ *		return 0;
+ *	}
+ *
+ * Licence: LGPL (v2 or any later version)
+ */
+int main(int argc, char *argv[])
+{
+	if (argc != 2)
+		return 1;
+
+	if (strcmp(argv[1], "depends") == 0) {
+		printf("ccan/crc\n");
+		return 0;
+	}
+
+	return 1;
+}