1 /*
2 * Simple XZ decoder command line tool
3 *
4 * Author: Lasse Collin <lasse.collin@tukaani.org>
5 *
6 * This file has been put into the public domain.
7 * You can do whatever you want with this file.
8 */
9
10 /*
11 * This is really limited: Not all filters from .xz format are supported,
12 * only CRC32 is supported as the integrity check, and decoding of
13 * concatenated .xz streams is not supported. Thus, you may want to look
14 * at xzdec from XZ Utils if a few KiB bigger tool is not a problem.
15 */
16
17 #include <stdbool.h>
18 #include <stdio.h>
19 #include <string.h>
20 #include "xz.h"
21
22 static uint8_t in[BUFSIZ];
23 static uint8_t out[BUFSIZ];
24
main(int argc,char ** argv)25 int main(int argc, char **argv)
26 {
27 struct xz_buf b;
28 struct xz_dec *s;
29 enum xz_ret ret;
30 const char *msg;
31
32 if (argc >= 2 && strcmp(argv[1], "--help") == 0) {
33 fputs("Uncompress a .xz file from stdin to stdout.\n"
34 "Arguments other than `--help' are ignored.\n",
35 stdout);
36 return 0;
37 }
38
39 xz_crc32_init();
40 #ifdef XZ_USE_CRC64
41 xz_crc64_init();
42 #endif
43
44 /*
45 * Support up to 64 MiB dictionary. The actually needed memory
46 * is allocated once the headers have been parsed.
47 */
48 s = xz_dec_init(XZ_DYNALLOC, 1 << 26);
49 if (s == NULL) {
50 msg = "Memory allocation failed\n";
51 goto error;
52 }
53
54 b.in = in;
55 b.in_pos = 0;
56 b.in_size = 0;
57 b.out = out;
58 b.out_pos = 0;
59 b.out_size = BUFSIZ;
60
61 while (true) {
62 if (b.in_pos == b.in_size) {
63 b.in_size = fread(in, 1, sizeof(in), stdin);
64 b.in_pos = 0;
65 }
66
67 ret = xz_dec_run(s, &b);
68
69 if (b.out_pos == sizeof(out)) {
70 if (fwrite(out, 1, b.out_pos, stdout) != b.out_pos) {
71 msg = "Write error\n";
72 goto error;
73 }
74
75 b.out_pos = 0;
76 }
77
78 if (ret == XZ_OK)
79 continue;
80
81 #ifdef XZ_DEC_ANY_CHECK
82 if (ret == XZ_UNSUPPORTED_CHECK) {
83 fputs(argv[0], stderr);
84 fputs(": ", stderr);
85 fputs("Unsupported check; not verifying "
86 "file integrity\n", stderr);
87 continue;
88 }
89 #endif
90
91 if (fwrite(out, 1, b.out_pos, stdout) != b.out_pos
92 || fclose(stdout)) {
93 msg = "Write error\n";
94 goto error;
95 }
96
97 switch (ret) {
98 case XZ_STREAM_END:
99 xz_dec_end(s);
100 return 0;
101
102 case XZ_MEM_ERROR:
103 msg = "Memory allocation failed\n";
104 goto error;
105
106 case XZ_MEMLIMIT_ERROR:
107 msg = "Memory usage limit reached\n";
108 goto error;
109
110 case XZ_FORMAT_ERROR:
111 msg = "Not a .xz file\n";
112 goto error;
113
114 case XZ_OPTIONS_ERROR:
115 msg = "Unsupported options in the .xz headers\n";
116 goto error;
117
118 case XZ_DATA_ERROR:
119 case XZ_BUF_ERROR:
120 msg = "File is corrupt\n";
121 goto error;
122
123 default:
124 msg = "Bug!\n";
125 goto error;
126 }
127 }
128
129 error:
130 xz_dec_end(s);
131 fputs(argv[0], stderr);
132 fputs(": ", stderr);
133 fputs(msg, stderr);
134 return 1;
135 }
136