LinuxGUI/Ventoy2Disk/Lib/xz-embedded/userspace/xzminidec.c

   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
  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 }