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
41 /*
42 * Support up to 64 MiB dictionary. The actually needed memory
43 * is allocated once the headers have been parsed.
44 */
45 s = xz_dec_init(XZ_DYNALLOC, 1 << 26);
46 if (s == NULL) {
47 msg = "Memory allocation failed\n";
48 goto error;
49 }
50
51 b.in = in;
52 b.in_pos = 0;
53 b.in_size = 0;
54 b.out = out;
55 b.out_pos = 0;
56 b.out_size = BUFSIZ;
57
58 while (true) {
59 if (b.in_pos == b.in_size) {
60 b.in_size = fread(in, 1, sizeof(in), stdin);
61 b.in_pos = 0;
62 }
63
64 ret = xz_dec_run(s, &b);
65
66 if (b.out_pos == sizeof(out)) {
67 if (fwrite(out, 1, b.out_pos, stdout) != b.out_pos) {
68 msg = "Write error\n";
69 goto error;
70 }
71
72 b.out_pos = 0;
73 }
74
75 if (ret == XZ_OK)
76 continue;
77
78 #ifdef XZ_DEC_ANY_CHECK
79 if (ret == XZ_UNSUPPORTED_CHECK) {
80 fputs(argv[0], stderr);
81 fputs(": ", stderr);
82 fputs("Unsupported check; not verifying "
83 "file integrity\n", stderr);
84 continue;
85 }
86 #endif
87
88 if (fwrite(out, 1, b.out_pos, stdout) != b.out_pos
89 || fclose(stdout)) {
90 msg = "Write error\n";
91 goto error;
92 }
93
94 switch (ret) {
95 case XZ_STREAM_END:
96 xz_dec_end(s);
97 return 0;
98
99 case XZ_MEM_ERROR:
100 msg = "Memory allocation failed\n";
101 goto error;
102
103 case XZ_MEMLIMIT_ERROR:
104 msg = "Memory usage limit reached\n";
105 goto error;
106
107 case XZ_FORMAT_ERROR:
108 msg = "Not a .xz file\n";
109 goto error;
110
111 case XZ_OPTIONS_ERROR:
112 msg = "Unsupported options in the .xz headers\n";
113 goto error;
114
115 case XZ_DATA_ERROR:
116 case XZ_BUF_ERROR:
117 msg = "File is corrupt\n";
118 goto error;
119
120 default:
121 msg = "Bug!\n";
122 goto error;
123 }
124 }
125
126 error:
127 xz_dec_end(s);
128 fputs(argv[0], stderr);
129 fputs(": ", stderr);
130 fputs(msg, stderr);
131 return 1;
132 }
133