[b08d3ed9] | 1 | /* FIXME: |
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| 2 | * 1. Symbolic links are not created. |
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| 3 | * 2. Untar_FromMemory has printfs. |
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| 4 | * 3. Untar_FromMemory uses FILE *fp. |
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| 5 | * 4. How to determine end of archive? |
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| 6 | * |
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| 7 | * Written by: Jake Janovetz <janovetz@tempest.ece.uiuc.edu> |
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| 8 | * |
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| 9 | * The license and distribution terms for this file may be |
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| 10 | * found in the file LICENSE in this distribution or at |
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| 11 | * http://www.OARcorp.com/rtems/license.html. |
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| 12 | * |
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| 13 | * $Id$ |
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| 14 | */ |
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| 15 | |
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| 16 | #include <stdio.h> |
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| 17 | #include <string.h> |
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| 18 | #include <stdlib.h> |
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| 19 | #include <unistd.h> |
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| 20 | #include <fcntl.h> |
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| 21 | #include "untar.h" |
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| 22 | |
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| 23 | |
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| 24 | /************************************************************************** |
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| 25 | * TAR file format: |
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| 26 | * |
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| 27 | * Offset Length Contents |
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| 28 | * 0 100 bytes File name ('\0' terminated, 99 maxmum length) |
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| 29 | * 100 8 bytes File mode (in octal ascii) |
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| 30 | * 108 8 bytes User ID (in octal ascii) |
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| 31 | * 116 8 bytes Group ID (in octal ascii) |
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| 32 | * 124 12 bytes File size (s) (in octal ascii) |
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| 33 | * 136 12 bytes Modify time (in octal ascii) |
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| 34 | * 148 8 bytes Header checksum (in octal ascii) |
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| 35 | * 156 1 bytes Link flag |
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| 36 | * 157 100 bytes Linkname ('\0' terminated, 99 maxmum length) |
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| 37 | * 257 8 bytes Magic ("ustar \0") |
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| 38 | * 265 32 bytes User name ('\0' terminated, 31 maxmum length) |
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| 39 | * 297 32 bytes Group name ('\0' terminated, 31 maxmum length) |
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| 40 | * 329 8 bytes Major device ID (in octal ascii) |
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| 41 | * 337 8 bytes Minor device ID (in octal ascii) |
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| 42 | * 345 167 bytes Padding |
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| 43 | * 512 (s+p)bytes File contents (s+p) := (((s) + 511) & ~511), |
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| 44 | * round up to 512 bytes |
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| 45 | * |
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| 46 | * Checksum: |
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| 47 | * int i, sum; |
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| 48 | * char* header = tar_header_pointer; |
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| 49 | * sum = 0; |
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| 50 | * for(i = 0; i < 512; i++) |
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| 51 | * sum += 0xFF & header[i]; |
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| 52 | *************************************************************************/ |
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| 53 | |
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| 54 | #define LF_OLDNORMAL '\0' /* Normal disk file, Unix compatible */ |
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| 55 | #define LF_NORMAL '0' /* Normal disk file */ |
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| 56 | #define LF_LINK '1' /* Link to previously dumped file */ |
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| 57 | #define LF_SYMLINK '2' /* Symbolic link */ |
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| 58 | #define LF_CHR '3' /* Character special file */ |
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| 59 | #define LF_BLK '4' /* Block special file */ |
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| 60 | #define LF_DIR '5' /* Directory */ |
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| 61 | #define LF_FIFO '6' /* FIFO special file */ |
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| 62 | #define LF_CONFIG '7' /* Contiguous file */ |
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| 63 | |
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| 64 | #define MAX_NAME_FIELD_SIZE 99 |
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| 65 | |
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| 66 | #define MIN(a,b) ((a)>(b)?(b):(a)) |
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| 67 | |
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| 68 | |
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| 69 | /************************************************************************** |
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| 70 | * This converts octal ASCII number representations into an |
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| 71 | * unsigned long. Only support 32-bit numbers for now. |
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| 72 | *************************************************************************/ |
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| 73 | static unsigned long |
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| 74 | octal2ulong(char *octascii, int len) |
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| 75 | { |
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| 76 | int i; |
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| 77 | unsigned long num; |
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| 78 | unsigned long mult; |
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| 79 | |
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| 80 | num = 0; |
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| 81 | mult = 1; |
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| 82 | for (i=len-1; i>=0; i--) |
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| 83 | { |
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| 84 | if ((octascii[i] < '0') || (octascii[i] > '9')) |
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| 85 | { |
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| 86 | continue; |
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| 87 | } |
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| 88 | num += mult*((unsigned long)(octascii[i] - '0')); |
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| 89 | mult *= 8; |
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| 90 | } |
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| 91 | return(num); |
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| 92 | } |
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| 93 | |
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| 94 | |
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| 95 | /************************************************************************** |
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| 96 | * Function: Untar_FromMemory * |
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| 97 | ************************************************************************** |
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| 98 | * Description: * |
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| 99 | * * |
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| 100 | * This is a simple subroutine used to rip links, directories, and * |
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| 101 | * files out of a block of memory. * |
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| 102 | * * |
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| 103 | * * |
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| 104 | * Inputs: * |
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| 105 | * * |
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| 106 | * unsigned char *tar_buf - Pointer to TAR buffer. * |
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| 107 | * unsigned long size - Length of TAR buffer. * |
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| 108 | * * |
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| 109 | * * |
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| 110 | * Output: * |
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| 111 | * * |
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| 112 | * int - UNTAR_SUCCESSFUL (0) on successful completion. * |
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| 113 | * UNTAR_INVALID_CHECKSUM for an invalid header checksum. * |
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| 114 | * UNTAR_INVALID_HEADER for an invalid header. * |
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| 115 | * * |
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| 116 | ************************************************************************** |
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| 117 | * Change History: * |
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| 118 | * 12/30/1998 - Creation (JWJ) * |
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| 119 | *************************************************************************/ |
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| 120 | int |
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| 121 | Untar_FromMemory(unsigned char *tar_buf, unsigned long size) |
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| 122 | { |
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| 123 | FILE *fp; |
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| 124 | char *bufr; |
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| 125 | size_t n; |
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| 126 | char fname[100]; |
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| 127 | char linkname[100]; |
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| 128 | int sum; |
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| 129 | int hdr_chksum; |
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| 130 | int retval; |
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| 131 | unsigned long ptr; |
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| 132 | unsigned long i; |
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| 133 | unsigned long nblocks; |
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| 134 | unsigned long file_size; |
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| 135 | unsigned char linkflag; |
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| 136 | |
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| 137 | |
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| 138 | ptr = 0; |
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| 139 | while (1) |
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| 140 | { |
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| 141 | if (ptr + 512 > size) |
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| 142 | { |
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| 143 | retval = UNTAR_SUCCESSFUL; |
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| 144 | break; |
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| 145 | } |
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| 146 | |
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| 147 | /* Read the header */ |
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| 148 | bufr = &tar_buf[ptr]; |
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| 149 | ptr += 512; |
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| 150 | if (strncmp(&bufr[257], "ustar ", 7)) |
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| 151 | { |
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| 152 | retval = UNTAR_SUCCESSFUL; |
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| 153 | break; |
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| 154 | } |
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| 155 | |
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| 156 | strncpy(fname, bufr, MAX_NAME_FIELD_SIZE); |
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| 157 | fname[MAX_NAME_FIELD_SIZE] = '\0'; |
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| 158 | |
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| 159 | linkflag = bufr[156]; |
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| 160 | file_size = octal2ulong(&bufr[124], 12); |
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| 161 | |
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| 162 | /****************************************************************** |
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| 163 | * Compute the TAR checksum and check with the value in |
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| 164 | * the archive. The checksum is computed over the entire |
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| 165 | * header, but the checksum field is substituted with blanks. |
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| 166 | ******************************************************************/ |
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| 167 | hdr_chksum = (int)octal2ulong(&bufr[148], 8); |
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| 168 | sum = 0; |
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| 169 | for (i=0; i<512; i++) |
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| 170 | { |
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| 171 | if ((i >= 148) && (i < 156)) |
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| 172 | { |
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| 173 | sum += 0xff & ' '; |
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| 174 | } |
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| 175 | else |
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| 176 | { |
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| 177 | sum += 0xff & bufr[i]; |
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| 178 | } |
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| 179 | } |
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| 180 | if (sum != hdr_chksum) |
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| 181 | { |
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| 182 | retval = UNTAR_INVALID_CHECKSUM; |
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| 183 | break; |
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| 184 | } |
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| 185 | |
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| 186 | |
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| 187 | /****************************************************************** |
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| 188 | * We've decoded the header, now figure out what it contains and |
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| 189 | * do something with it. |
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| 190 | *****************************************************************/ |
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| 191 | if (linkflag == LF_SYMLINK) |
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| 192 | { |
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| 193 | strncpy(linkname, &bufr[157], MAX_NAME_FIELD_SIZE); |
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| 194 | linkname[MAX_NAME_FIELD_SIZE] = '\0'; |
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| 195 | /* symlink(fname, linkname); */ |
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| 196 | } |
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| 197 | else if (linkflag == LF_NORMAL) |
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| 198 | { |
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| 199 | nblocks = (((file_size) + 511) & ~511) / 512; |
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| 200 | if ((fp = fopen(fname, "w")) == NULL) |
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| 201 | { |
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| 202 | printf("Untar failed to create file %s\n", fname); |
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| 203 | ptr += 512 * nblocks; |
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| 204 | } |
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| 205 | else |
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| 206 | { |
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| 207 | unsigned long sizeToGo = file_size; |
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| 208 | unsigned long len; |
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| 209 | |
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| 210 | /*************************************************************** |
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| 211 | * Read out the data. There are nblocks of data where nblocks |
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| 212 | * is the file_size rounded to the nearest 512-byte boundary. |
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| 213 | **************************************************************/ |
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| 214 | for (i=0; i<nblocks; i++) |
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| 215 | { |
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| 216 | len = ((sizeToGo < 512L)?(sizeToGo):(512L)); |
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| 217 | n = fwrite(&tar_buf[ptr], 1, len, fp); |
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| 218 | if (n != len) |
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| 219 | { |
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| 220 | printf("Error during write\n"); |
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| 221 | break; |
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| 222 | } |
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| 223 | ptr += 512; |
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| 224 | sizeToGo -= n; |
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| 225 | } |
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| 226 | fclose(fp); |
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| 227 | } |
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| 228 | } |
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| 229 | else if (linkflag == LF_DIR) |
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| 230 | { |
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| 231 | mkdir(fname, S_IRWXU | S_IRWXG | S_IRWXO); |
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| 232 | } |
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| 233 | } |
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| 234 | |
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| 235 | return(retval); |
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| 236 | } |
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| 237 | |
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| 238 | |
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| 239 | /************************************************************************** |
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| 240 | * Function: Untar_FromFile * |
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| 241 | ************************************************************************** |
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| 242 | * Description: * |
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| 243 | * * |
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| 244 | * This is a simple subroutine used to rip links, directories, and * |
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| 245 | * files out of a TAR file. * |
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| 246 | * * |
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| 247 | * * |
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| 248 | * Inputs: * |
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| 249 | * * |
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| 250 | * char *tar_name - TAR filename. * |
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| 251 | * * |
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| 252 | * * |
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| 253 | * Output: * |
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| 254 | * * |
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| 255 | * int - UNTAR_SUCCESSFUL (0) on successful completion. * |
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| 256 | * UNTAR_INVALID_CHECKSUM for an invalid header checksum. * |
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| 257 | * UNTAR_INVALID_HEADER for an invalid header. * |
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| 258 | * * |
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| 259 | ************************************************************************** |
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| 260 | * Change History: * |
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| 261 | * 12/30/1998 - Creation (JWJ) * |
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| 262 | *************************************************************************/ |
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| 263 | int |
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| 264 | Untar_FromFile(char *tar_name) |
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| 265 | { |
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| 266 | int fd; |
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| 267 | char *bufr; |
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| 268 | size_t n; |
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| 269 | char fname[100]; |
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| 270 | char linkname[100]; |
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| 271 | int sum; |
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| 272 | int hdr_chksum; |
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| 273 | int retval; |
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| 274 | unsigned long i; |
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| 275 | unsigned long nblocks; |
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| 276 | unsigned long size; |
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| 277 | unsigned char linkflag; |
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| 278 | |
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| 279 | |
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| 280 | retval = UNTAR_SUCCESSFUL; |
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| 281 | bufr = (char *)malloc(512); |
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| 282 | if (bufr == NULL) |
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| 283 | { |
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| 284 | return(UNTAR_FAIL); |
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| 285 | } |
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| 286 | |
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| 287 | fd = open(tar_name, O_RDONLY); |
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| 288 | while (1) |
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| 289 | { |
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| 290 | /* Read the header */ |
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| 291 | /* If the header read fails, we just consider it the end |
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| 292 | of the tarfile. */ |
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| 293 | if ((n = read(fd, bufr, 512)) != 512) |
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| 294 | { |
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| 295 | break; |
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| 296 | } |
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| 297 | |
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| 298 | if (strncmp(&bufr[257], "ustar ", 7)) |
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| 299 | { |
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| 300 | break; |
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| 301 | } |
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| 302 | |
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| 303 | strncpy(fname, bufr, MAX_NAME_FIELD_SIZE); |
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| 304 | fname[MAX_NAME_FIELD_SIZE] = '\0'; |
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| 305 | |
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| 306 | linkflag = bufr[156]; |
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| 307 | size = octal2ulong(&bufr[124], 12); |
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| 308 | |
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| 309 | /****************************************************************** |
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| 310 | * Compute the TAR checksum and check with the value in |
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| 311 | * the archive. The checksum is computed over the entire |
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| 312 | * header, but the checksum field is substituted with blanks. |
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| 313 | ******************************************************************/ |
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| 314 | hdr_chksum = (int)octal2ulong(&bufr[148], 8); |
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| 315 | sum = 0; |
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| 316 | for (i=0; i<512; i++) |
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| 317 | { |
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| 318 | if ((i >= 148) && (i < 156)) |
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| 319 | { |
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| 320 | sum += 0xff & ' '; |
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| 321 | } |
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| 322 | else |
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| 323 | { |
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| 324 | sum += 0xff & bufr[i]; |
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| 325 | } |
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| 326 | } |
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| 327 | if (sum != hdr_chksum) |
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| 328 | { |
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| 329 | retval = UNTAR_INVALID_CHECKSUM; |
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| 330 | break; |
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| 331 | } |
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| 332 | |
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| 333 | |
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| 334 | /****************************************************************** |
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| 335 | * We've decoded the header, now figure out what it contains and |
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| 336 | * do something with it. |
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| 337 | *****************************************************************/ |
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| 338 | if (linkflag == LF_SYMLINK) |
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| 339 | { |
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| 340 | strncpy(linkname, &bufr[157], MAX_NAME_FIELD_SIZE); |
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| 341 | linkname[MAX_NAME_FIELD_SIZE] = '\0'; |
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| 342 | } |
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| 343 | else if (linkflag == LF_NORMAL) |
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| 344 | { |
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| 345 | int out_fd; |
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| 346 | |
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| 347 | /****************************************************************** |
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| 348 | * Read out the data. There are nblocks of data where nblocks |
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| 349 | * is the size rounded to the nearest 512-byte boundary. |
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| 350 | *****************************************************************/ |
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| 351 | nblocks = (((size) + 511) & ~511) / 512; |
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| 352 | |
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| 353 | if ((out_fd = creat(fname, 0644)) == -1) |
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| 354 | { |
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| 355 | for (i=0; i<nblocks; i++) |
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| 356 | { |
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| 357 | n = read(fd, bufr, 512); |
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| 358 | } |
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| 359 | } |
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| 360 | else |
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| 361 | { |
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| 362 | for (i=0; i<nblocks; i++) |
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| 363 | { |
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| 364 | n = read(fd, bufr, 512); |
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| 365 | n = MIN(n, size - i*512); |
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| 366 | write(out_fd, bufr, n); |
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| 367 | } |
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| 368 | close(out_fd); |
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| 369 | } |
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| 370 | } |
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| 371 | else if (linkflag == LF_DIR) |
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| 372 | { |
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| 373 | mkdir(fname, S_IRWXU | S_IRWXG | S_IRWXO); |
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| 374 | } |
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| 375 | } |
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| 376 | free(bufr); |
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| 377 | close(fd); |
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| 378 | |
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| 379 | return(retval); |
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| 380 | } |
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| 381 | |
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