1 | /* minigzip.c -- simulate gzip using the zlib compression library |
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2 | * Copyright (C) 1995-2002 Jean-loup Gailly. |
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3 | * For conditions of distribution and use, see copyright notice in zlib.h |
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4 | */ |
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5 | |
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6 | /* |
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7 | * minigzip is a minimal implementation of the gzip utility. This is |
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8 | * only an example of using zlib and isn't meant to replace the |
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9 | * full-featured gzip. No attempt is made to deal with file systems |
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10 | * limiting names to 14 or 8+3 characters, etc... Error checking is |
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11 | * very limited. So use minigzip only for testing; use gzip for the |
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12 | * real thing. On MSDOS, use only on file names without extension |
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13 | * or in pipe mode. |
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14 | */ |
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15 | |
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16 | /* @(#) $Id: minigzip.c,v 1.1.1.2 2002-03-12 17:19:03 zacheiss Exp $ */ |
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17 | |
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18 | #include <stdio.h> |
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19 | #include "zlib.h" |
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20 | |
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21 | #ifdef STDC |
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22 | # include <string.h> |
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23 | # include <stdlib.h> |
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24 | #else |
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25 | extern void exit OF((int)); |
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26 | #endif |
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27 | |
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28 | #ifdef USE_MMAP |
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29 | # include <sys/types.h> |
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30 | # include <sys/mman.h> |
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31 | # include <sys/stat.h> |
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32 | #endif |
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33 | |
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34 | #if defined(MSDOS) || defined(OS2) || defined(WIN32) |
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35 | # include <fcntl.h> |
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36 | # include <io.h> |
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37 | # define SET_BINARY_MODE(file) setmode(fileno(file), O_BINARY) |
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38 | #else |
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39 | # define SET_BINARY_MODE(file) |
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40 | #endif |
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41 | |
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42 | #ifdef VMS |
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43 | # define unlink delete |
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44 | # define GZ_SUFFIX "-gz" |
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45 | #endif |
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46 | #ifdef RISCOS |
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47 | # define unlink remove |
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48 | # define GZ_SUFFIX "-gz" |
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49 | # define fileno(file) file->__file |
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50 | #endif |
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51 | #if defined(__MWERKS__) && __dest_os != __be_os && __dest_os != __win32_os |
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52 | # include <unix.h> /* for fileno */ |
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53 | #endif |
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54 | |
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55 | #ifndef WIN32 /* unlink already in stdio.h for WIN32 */ |
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56 | extern int unlink OF((const char *)); |
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57 | #endif |
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58 | |
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59 | #ifndef GZ_SUFFIX |
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60 | # define GZ_SUFFIX ".gz" |
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61 | #endif |
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62 | #define SUFFIX_LEN (sizeof(GZ_SUFFIX)-1) |
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63 | |
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64 | #define BUFLEN 16384 |
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65 | #define MAX_NAME_LEN 1024 |
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66 | |
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67 | #ifdef MAXSEG_64K |
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68 | # define local static |
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69 | /* Needed for systems with limitation on stack size. */ |
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70 | #else |
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71 | # define local |
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72 | #endif |
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73 | |
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74 | char *prog; |
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75 | |
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76 | void error OF((const char *msg)); |
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77 | void gz_compress OF((FILE *in, gzFile out)); |
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78 | #ifdef USE_MMAP |
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79 | int gz_compress_mmap OF((FILE *in, gzFile out)); |
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80 | #endif |
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81 | void gz_uncompress OF((gzFile in, FILE *out)); |
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82 | void file_compress OF((char *file, char *mode)); |
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83 | void file_uncompress OF((char *file)); |
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84 | int main OF((int argc, char *argv[])); |
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85 | |
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86 | /* =========================================================================== |
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87 | * Display error message and exit |
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88 | */ |
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89 | void error(msg) |
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90 | const char *msg; |
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91 | { |
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92 | fprintf(stderr, "%s: %s\n", prog, msg); |
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93 | exit(1); |
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94 | } |
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95 | |
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96 | /* =========================================================================== |
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97 | * Compress input to output then close both files. |
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98 | */ |
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99 | |
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100 | void gz_compress(in, out) |
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101 | FILE *in; |
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102 | gzFile out; |
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103 | { |
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104 | local char buf[BUFLEN]; |
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105 | int len; |
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106 | int err; |
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107 | |
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108 | #ifdef USE_MMAP |
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109 | /* Try first compressing with mmap. If mmap fails (minigzip used in a |
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110 | * pipe), use the normal fread loop. |
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111 | */ |
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112 | if (gz_compress_mmap(in, out) == Z_OK) return; |
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113 | #endif |
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114 | for (;;) { |
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115 | len = fread(buf, 1, sizeof(buf), in); |
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116 | if (ferror(in)) { |
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117 | perror("fread"); |
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118 | exit(1); |
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119 | } |
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120 | if (len == 0) break; |
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121 | |
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122 | if (gzwrite(out, buf, (unsigned)len) != len) error(gzerror(out, &err)); |
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123 | } |
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124 | fclose(in); |
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125 | if (gzclose(out) != Z_OK) error("failed gzclose"); |
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126 | } |
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127 | |
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128 | #ifdef USE_MMAP /* MMAP version, Miguel Albrecht <malbrech@eso.org> */ |
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129 | |
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130 | /* Try compressing the input file at once using mmap. Return Z_OK if |
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131 | * if success, Z_ERRNO otherwise. |
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132 | */ |
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133 | int gz_compress_mmap(in, out) |
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134 | FILE *in; |
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135 | gzFile out; |
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136 | { |
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137 | int len; |
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138 | int err; |
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139 | int ifd = fileno(in); |
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140 | caddr_t buf; /* mmap'ed buffer for the entire input file */ |
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141 | off_t buf_len; /* length of the input file */ |
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142 | struct stat sb; |
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143 | |
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144 | /* Determine the size of the file, needed for mmap: */ |
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145 | if (fstat(ifd, &sb) < 0) return Z_ERRNO; |
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146 | buf_len = sb.st_size; |
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147 | if (buf_len <= 0) return Z_ERRNO; |
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148 | |
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149 | /* Now do the actual mmap: */ |
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150 | buf = mmap((caddr_t) 0, buf_len, PROT_READ, MAP_SHARED, ifd, (off_t)0); |
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151 | if (buf == (caddr_t)(-1)) return Z_ERRNO; |
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152 | |
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153 | /* Compress the whole file at once: */ |
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154 | len = gzwrite(out, (char *)buf, (unsigned)buf_len); |
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155 | |
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156 | if (len != (int)buf_len) error(gzerror(out, &err)); |
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157 | |
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158 | munmap(buf, buf_len); |
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159 | fclose(in); |
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160 | if (gzclose(out) != Z_OK) error("failed gzclose"); |
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161 | return Z_OK; |
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162 | } |
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163 | #endif /* USE_MMAP */ |
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164 | |
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165 | /* =========================================================================== |
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166 | * Uncompress input to output then close both files. |
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167 | */ |
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168 | void gz_uncompress(in, out) |
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169 | gzFile in; |
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170 | FILE *out; |
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171 | { |
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172 | local char buf[BUFLEN]; |
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173 | int len; |
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174 | int err; |
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175 | |
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176 | for (;;) { |
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177 | len = gzread(in, buf, sizeof(buf)); |
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178 | if (len < 0) error (gzerror(in, &err)); |
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179 | if (len == 0) break; |
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180 | |
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181 | if ((int)fwrite(buf, 1, (unsigned)len, out) != len) { |
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182 | error("failed fwrite"); |
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183 | } |
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184 | } |
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185 | if (fclose(out)) error("failed fclose"); |
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186 | |
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187 | if (gzclose(in) != Z_OK) error("failed gzclose"); |
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188 | } |
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189 | |
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190 | |
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191 | /* =========================================================================== |
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192 | * Compress the given file: create a corresponding .gz file and remove the |
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193 | * original. |
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194 | */ |
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195 | void file_compress(file, mode) |
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196 | char *file; |
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197 | char *mode; |
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198 | { |
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199 | local char outfile[MAX_NAME_LEN]; |
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200 | FILE *in; |
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201 | gzFile out; |
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202 | |
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203 | strcpy(outfile, file); |
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204 | strcat(outfile, GZ_SUFFIX); |
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205 | |
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206 | in = fopen(file, "rb"); |
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207 | if (in == NULL) { |
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208 | perror(file); |
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209 | exit(1); |
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210 | } |
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211 | out = gzopen(outfile, mode); |
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212 | if (out == NULL) { |
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213 | fprintf(stderr, "%s: can't gzopen %s\n", prog, outfile); |
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214 | exit(1); |
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215 | } |
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216 | gz_compress(in, out); |
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217 | |
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218 | unlink(file); |
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219 | } |
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220 | |
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221 | |
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222 | /* =========================================================================== |
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223 | * Uncompress the given file and remove the original. |
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224 | */ |
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225 | void file_uncompress(file) |
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226 | char *file; |
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227 | { |
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228 | local char buf[MAX_NAME_LEN]; |
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229 | char *infile, *outfile; |
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230 | FILE *out; |
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231 | gzFile in; |
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232 | int len = strlen(file); |
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233 | |
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234 | strcpy(buf, file); |
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235 | |
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236 | if (len > SUFFIX_LEN && strcmp(file+len-SUFFIX_LEN, GZ_SUFFIX) == 0) { |
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237 | infile = file; |
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238 | outfile = buf; |
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239 | outfile[len-3] = '\0'; |
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240 | } else { |
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241 | outfile = file; |
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242 | infile = buf; |
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243 | strcat(infile, GZ_SUFFIX); |
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244 | } |
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245 | in = gzopen(infile, "rb"); |
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246 | if (in == NULL) { |
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247 | fprintf(stderr, "%s: can't gzopen %s\n", prog, infile); |
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248 | exit(1); |
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249 | } |
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250 | out = fopen(outfile, "wb"); |
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251 | if (out == NULL) { |
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252 | perror(file); |
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253 | exit(1); |
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254 | } |
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255 | |
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256 | gz_uncompress(in, out); |
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257 | |
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258 | unlink(infile); |
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259 | } |
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260 | |
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261 | |
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262 | /* =========================================================================== |
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263 | * Usage: minigzip [-d] [-f] [-h] [-1 to -9] [files...] |
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264 | * -d : decompress |
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265 | * -f : compress with Z_FILTERED |
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266 | * -h : compress with Z_HUFFMAN_ONLY |
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267 | * -1 to -9 : compression level |
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268 | */ |
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269 | |
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270 | int main(argc, argv) |
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271 | int argc; |
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272 | char *argv[]; |
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273 | { |
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274 | int uncompr = 0; |
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275 | gzFile file; |
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276 | char outmode[20]; |
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277 | |
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278 | strcpy(outmode, "wb6 "); |
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279 | |
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280 | prog = argv[0]; |
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281 | argc--, argv++; |
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282 | |
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283 | while (argc > 0) { |
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284 | if (strcmp(*argv, "-d") == 0) |
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285 | uncompr = 1; |
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286 | else if (strcmp(*argv, "-f") == 0) |
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287 | outmode[3] = 'f'; |
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288 | else if (strcmp(*argv, "-h") == 0) |
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289 | outmode[3] = 'h'; |
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290 | else if ((*argv)[0] == '-' && (*argv)[1] >= '1' && (*argv)[1] <= '9' && |
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291 | (*argv)[2] == 0) |
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292 | outmode[2] = (*argv)[1]; |
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293 | else |
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294 | break; |
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295 | argc--, argv++; |
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296 | } |
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297 | if (argc == 0) { |
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298 | SET_BINARY_MODE(stdin); |
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299 | SET_BINARY_MODE(stdout); |
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300 | if (uncompr) { |
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301 | file = gzdopen(fileno(stdin), "rb"); |
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302 | if (file == NULL) error("can't gzdopen stdin"); |
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303 | gz_uncompress(file, stdout); |
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304 | } else { |
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305 | file = gzdopen(fileno(stdout), outmode); |
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306 | if (file == NULL) error("can't gzdopen stdout"); |
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307 | gz_compress(stdin, file); |
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308 | } |
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309 | } else { |
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310 | do { |
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311 | if (uncompr) { |
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312 | file_uncompress(*argv); |
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313 | } else { |
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314 | file_compress(*argv, outmode); |
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315 | } |
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316 | } while (argv++, --argc); |
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317 | } |
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318 | exit(0); |
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319 | return 0; /* to avoid warning */ |
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320 | } |
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