--- /dev/null
+/*
+ * compressfile.c
+ *
+ * An example of using wimlib's compression API to compress a file.
+ *
+ * This program does *not* have anything to do with WIM files other than the
+ * fact that this makes use of compression formats that are used in WIM files.
+ * This is purely an example of using the compression API.
+ *
+ * Compile with:
+ *
+ * $ gcc compressfile.c -o compressfile -lwim
+ *
+ * Run with:
+ *
+ * $ ./compressfile INFILE OUTFILE [LZX | XPRESS | LZMS] [chunk size]
+ *
+ *
+ * Use the decompressfile.c program to decompress the file.
+ *
+ * For example:
+ *
+ * $ ./compressfile book.txt book.txt.lzms LZMS 1048576
+ * $ rm -f book.txt
+ * $ ./decompressfile book.txt.lzms book.txt
+ *
+ * The compressed file format created here is simply a series of compressed
+ * chunks. A real format would need to have checksums and other metadata.
+ */
+
+#define _GNU_SOURCE
+#define _FILE_OFFSET_BITS 64
+
+#include <wimlib.h>
+
+#include <errno.h>
+#include <error.h>
+#include <fcntl.h>
+#include <inttypes.h>
+#include <stdlib.h>
+#include <string.h>
+#include <unistd.h>
+
+static void
+do_compress(int in_fd, const char *in_filename,
+ int out_fd, const char *out_filename,
+ uint32_t chunk_size, struct wimlib_compressor *compressor)
+{
+ char *ubuf = malloc(chunk_size);
+ char *cbuf = malloc(chunk_size - 1);
+ uint64_t chunk_num;
+
+ for (chunk_num = 1; ; chunk_num++) {
+ ssize_t bytes_read;
+ size_t csize;
+ char *out_buf;
+ uint32_t out_size;
+ uint32_t usize;
+
+ /* Read next chunk of data to compress. */
+ bytes_read = read(in_fd, ubuf, chunk_size);
+ if (bytes_read <= 0) {
+ if (bytes_read == 0)
+ break;
+ error(1, errno, "Error reading \"%s\"", in_filename);
+ }
+
+ /* Compress the chunk. */
+ usize = bytes_read;
+
+ csize = wimlib_compress(ubuf, usize, cbuf, usize - 1, compressor);
+ if (csize != 0) {
+ /* Chunk was compressed; use the compressed data. */
+ out_buf = cbuf;
+ out_size = csize;
+ } else {
+ /* Chunk did not compress to less than original size;
+ * use the uncompressed data. */
+ out_buf = ubuf;
+ out_size = usize;
+ }
+
+ printf("Chunk %"PRIu64": %"PRIu32" => %"PRIu32" bytes\n",
+ chunk_num, usize, out_size);
+
+ /* Output the uncompressed chunk size, the compressed chunk
+ * size, then the chunk data. Note: a real program would need
+ * to output the chunk sizes in consistent endianness. */
+ if (write(out_fd, &usize, sizeof(uint32_t)) != sizeof(uint32_t) ||
+ write(out_fd, &out_size, sizeof(uint32_t)) != sizeof(uint32_t) ||
+ write(out_fd, out_buf, out_size) != out_size)
+ {
+ error(1, errno, "Error writing to \"%s\"",
+ out_filename);
+ }
+ }
+ free(ubuf);
+ free(cbuf);
+}
+
+int main(int argc, char **argv)
+{
+ const char *in_filename;
+ const char *out_filename;
+ int in_fd;
+ int out_fd;
+ struct wimlib_compressor *compressor;
+ int ctype = WIMLIB_COMPRESSION_TYPE_LZX;
+ uint32_t chunk_size = 32768;
+ int ret;
+
+ if (argc < 3 || argc > 5) {
+ fprintf(stderr, "Usage: %s INFILE OUTFILE "
+ "[LZX | XPRESS | LZMS] [chunk size]\n", argv[0]);
+ return 2;
+ }
+
+ in_filename = argv[1];
+ out_filename = argv[2];
+
+ /* Parse compression type (optional) */
+ if (argc >= 4) {
+ if (!strcmp(argv[3], "LZX"))
+ ctype = WIMLIB_COMPRESSION_TYPE_LZX;
+ else if (!strcmp(argv[3], "XPRESS"))
+ ctype = WIMLIB_COMPRESSION_TYPE_XPRESS;
+ else if (!strcmp(argv[3], "LZMS"))
+ ctype = WIMLIB_COMPRESSION_TYPE_LZMS;
+ else
+ error(1, 0, "Unrecognized compression type \"%s\"", argv[3]);
+ }
+ /* Parse chunk size (optional). */
+ if (argc >= 5)
+ chunk_size = atoi(argv[4]);
+
+ /* Open input file and output file. */
+ in_fd = open(in_filename, O_RDONLY);
+ if (in_fd < 0)
+ error(1, errno, "Failed to open \"%s\"", in_filename);
+ out_fd = open(out_filename, O_WRONLY | O_TRUNC | O_CREAT, 0644);
+ if (out_fd < 0)
+ error(1, errno, "Failed to open \"%s\"", out_filename);
+
+ /* Create a compressor for the compression type and chunk size with the
+ * default parameters. */
+ ret = wimlib_create_compressor(ctype, chunk_size, NULL, &compressor);
+ if (ret != 0)
+ error(1, 0, "Failed to create compressor: %s",
+ wimlib_get_error_string(ret));
+
+ uint32_t ctype32 = ctype;
+ /* Write compression type and chunk size to the file. */
+ if (write(out_fd, &ctype32, sizeof(uint32_t)) != sizeof(uint32_t) ||
+ write(out_fd, &chunk_size, sizeof(uint32_t)) != sizeof(uint32_t))
+ {
+ error(1, errno, "Error writing to \"%s\"",
+ out_filename);
+ }
+
+ /* Compress and write the data. */
+ do_compress(in_fd, in_filename,
+ out_fd, out_filename,
+ chunk_size, compressor);
+
+ /* Cleanup and return. */
+ if (close(out_fd))
+ error(1, errno, "Error closing \"%s\"", out_filename);
+ wimlib_free_compressor(compressor);
+ return 0;
+}
git://wimlib.net / wimlib / blobdiff