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
65 if (ferror(stdin)) {
66 msg = "Read error\n";
67 goto error;
68 }
69
70 b.in_pos = 0;
71 }
72
73 /*
74 * There are a few ways to set the "finish" (the third)
75 * argument. We could use feof(stdin) but testing in_size
76 * is fine too and may also work in applications that don't
77 * use FILEs.
78 */
79 ret = xz_dec_catrun(s, &b, b.in_size == 0);
80
81 if (b.out_pos == sizeof(out)) {
82 if (fwrite(out, 1, b.out_pos, stdout) != b.out_pos) {
83 msg = "Write error\n";
84 goto error;
85 }
86
87 b.out_pos = 0;
88 }
89
90 if (ret == XZ_OK)
91 continue;
92
93 #ifdef XZ_DEC_ANY_CHECK
94 if (ret == XZ_UNSUPPORTED_CHECK) {
95 fputs(argv[0], stderr);
96 fputs(": ", stderr);
97 fputs("Unsupported check; not verifying "
98 "file integrity\n", stderr);
99 continue;
100 }
101 #endif
102
103 if (fwrite(out, 1, b.out_pos, stdout) != b.out_pos
104 || fclose(stdout)) {
105 msg = "Write error\n";
106 goto error;
107 }
108
109 switch (ret) {
110 case XZ_STREAM_END:
111 xz_dec_end(s);
112 return 0;
113
114 case XZ_MEM_ERROR:
115 msg = "Memory allocation failed\n";
116 goto error;
117
118 case XZ_MEMLIMIT_ERROR:
119 msg = "Memory usage limit reached\n";
120 goto error;
121
122 case XZ_FORMAT_ERROR:
123 msg = "Not a .xz file\n";
124 goto error;
125
126 case XZ_OPTIONS_ERROR:
127 msg = "Unsupported options in the .xz headers\n";
128 goto error;
129
130 case XZ_DATA_ERROR:
131 case XZ_BUF_ERROR:
132 msg = "File is corrupt\n";
133 goto error;
134
135 default:
136 msg = "Bug!\n";
137 goto error;
138 }
139 }
140
141 error:
142 xz_dec_end(s);
143 fputs(argv[0], stderr);
144 fputs(": ", stderr);
145 fputs(msg, stderr);
146 return 1;
147 }
148