--- /dev/null
+#include <string.h>
+#include "config.h"
+
+/**
+ * bdelta - Generate and apply binary deltas
+ *
+ * This library takes two strings containing binary data, and produces a
+ * "patch" that can be applied to the first one to produce the second one.
+ * It can be used to save bandwidth and disk space when many texts differing
+ * by a small number of bytes need to be transmitted or stored.
+ *
+ * Patches produced by this version of the library can be applied using future
+ * versions, but not past versions.
+ *
+ * bdelta implements the algorithm described in
+ * An O(ND) Difference Algorithm and Its Variations by Eugene W. Myers.
+ * Because its memory usage and expected running time are O(N + D^2),
+ * it works well only when the strings differ by a small number of bytes.
+ * This implementation stops trying when the strings differ by more than
+ * 1000 bytes, and falls back to producing a patch that simply emits the new
+ * string.
+ *
+ * Thus, bdelta does not save any space when given two strings that differ by
+ * more than 1000 bytes. This may be improved in a future version of the
+ * library.
+ *
+ * Example:
+ * #include <ccan/bdelta/bdelta.h>
+ * #include <stdio.h>
+ * #include <stdlib.h>
+ * #include <string.h>
+ *
+ * static void gulp(const char *filename, void **data_out, size_t *size_out);
+ *
+ * static int usage(const char *prog)
+ * {
+ * fprintf(
+ * stderr,
+ * "Usage: %s diff <old> <new> > <patch>\n"
+ * " %s patch <old> <patch> > <new>\n",
+ * prog, prog
+ * );
+ * return 1;
+ * }
+ *
+ * int main(int argc, char *argv[])
+ * {
+ * void *old, *new_, *patch;
+ * size_t old_size, new_size, patch_size;
+ * BDELTAcode rc;
+ *
+ * if (argc != 4)
+ * return usage(argv[0]);
+ *
+ * if (strcmp(argv[1], "diff") == 0) {
+ * gulp(argv[2], &old, &old_size);
+ * gulp(argv[3], &new_, &new_size);
+ *
+ * rc = bdelta_diff(old, old_size, new_, new_size, &patch, &patch_size);
+ * if (rc != BDELTA_OK) {
+ * bdelta_perror("bdelta_diff", rc);
+ * return 1;
+ * }
+ *
+ * if (fwrite(patch, 1, patch_size, stdout) != patch_size) {
+ * perror("stdout");
+ * return 1;
+ * }
+ * } else if (strcmp(argv[1], "patch") == 0) {
+ * gulp(argv[2], &old, &old_size);
+ * gulp(argv[3], &patch, &patch_size);
+ *
+ * rc = bdelta_patch(old, old_size, patch, patch_size, &new_, &new_size);
+ * if (rc != BDELTA_OK) {
+ * bdelta_perror("bdelta_patch", rc);
+ * return 1;
+ * }
+ *
+ * if (fwrite(new_, 1, new_size, stdout) != new_size) {
+ * perror("stdout");
+ * return 1;
+ * }
+ * } else {
+ * return usage(argv[0]);
+ * }
+ *
+ * free(old);
+ * free(new_);
+ * free(patch);
+ * return 0;
+ * }
+ *
+ * static void gulp(const char *filename, void **data_out, size_t *size_out)
+ * {
+ * FILE *f = fopen(filename, "rb");
+ * size_t size = 0;
+ * size_t alloc = 16;
+ * char *data = malloc(alloc);
+ *
+ * if (f == NULL || data == NULL)
+ * goto error;
+ *
+ * for (;;) {
+ * size += fread(data + size, 1, alloc - size, f);
+ * if (size < alloc) {
+ * if (!feof(f))
+ * goto error;
+ * break;
+ * }
+ * data = realloc(data, alloc *= 2);
+ * if (data == NULL)
+ * goto error;
+ * }
+ *
+ * if (fclose(f) != 0)
+ * goto error;
+ *
+ * *data_out = data;
+ * *size_out = size;
+ * return;
+ *
+ * error:
+ * perror(filename);
+ * exit(EXIT_FAILURE);
+ * }
+ *
+ * Author: Joey Adams <joeyadams3.14159@gmail.com>
+ * License: MIT
+ * Version: 0.1.1
+ */
+int main(int argc, char *argv[])
+{
+ /* Expect exactly one argument */
+ if (argc != 2)
+ return 1;
+
+ if (strcmp(argv[1], "depends") == 0) {
+ /* Nothing */
+ return 0;
+ }
+
+ return 1;
+}