lib/util.c

   1 /*
   2 **  Copyright 1998-2003 University of Illinois Board of Trustees
   3 **  Copyright 1998-2003 Mark D. Roth
   4 **  All rights reserved.
   5 **
   6 **  util.c - miscellaneous utility code for libtar
   7 **
   8 **  Mark D. Roth <roth@uiuc.edu>
   9 **  Campus Information Technologies and Educational Services
  10 **  University of Illinois at Urbana-Champaign
  11 */
  12
  13 #include <internal.h>
  14
  15 #include <stdio.h>
  16 #include <sys/param.h>
  17 #include <errno.h>
  18
  19 #ifdef STDC_HEADERS
  20 # include <string.h>
  21 #endif
  22
  23
  24 /* hashing function for pathnames */
  25 int
  26 path_hashfunc(char *key, int numbuckets)
  27 {
  28         char buf[MAXPATHLEN];
  29         char *p;
  30
  31         strcpy(buf, key);
  32         p = basename(buf);
  33
  34         return (((unsigned int)p[0]) % numbuckets);
  35 }
  36
  37
  38 /* matching function for dev_t's */
  39 int
  40 dev_match(dev_t *dev1, dev_t *dev2)
  41 {
  42         return !memcmp(dev1, dev2, sizeof(dev_t));
  43 }
  44
  45
  46 /* matching function for ino_t's */
  47 int
  48 ino_match(ino_t *ino1, ino_t *ino2)
  49 {
  50         return !memcmp(ino1, ino2, sizeof(ino_t));
  51 }
  52
  53
  54 /* hashing function for dev_t's */
  55 int
  56 dev_hash(dev_t *dev)
  57 {
  58         return *dev % 16;
  59 }
  60
  61
  62 /* hashing function for ino_t's */
  63 int
  64 ino_hash(ino_t *inode)
  65 {
  66         return *inode % 256;
  67 }
  68
  69
  70 /*
  71 ** mkdirhier() - create all directories in a given path
  72 ** returns:
  73 **      0                       success
  74 **      1                       all directories already exist
  75 **      -1 (and sets errno)     error
  76 */
  77 int
  78 mkdirhier(char *path)
  79 {
  80         char src[MAXPATHLEN], dst[MAXPATHLEN] = "";
  81         char *dirp, *nextp = src;
  82         int retval = 1;
  83
  84         if (strlcpy(src, path, sizeof(src)) > sizeof(src))
  85         {
  86                 errno = ENAMETOOLONG;
  87                 return -1;
  88         }
  89
  90         if (path[0] == '/')
  91                 strcpy(dst, "/");
  92
  93         while ((dirp = strsep(&nextp, "/")) != NULL)
  94         {
  95                 if (*dirp == '\0')
  96                         continue;
  97
  98                 if (dst[0] != '\0')
  99                         strcat(dst, "/");
 100                 strcat(dst, dirp);
 101
 102                 if (mkdir(dst, 0777) == -1)
 103                 {
 104                         if (errno != EEXIST)
 105                                 return -1;
 106                 }
 107                 else
 108                         retval = 0;
 109         }
 110
 111         return retval;
 112 }
 113
 114
 115 /* calculate header checksum */
 116 int
 117 th_crc_calc(TAR *t)
 118 {
 119         int i, sum = 0;
 120
 121         for (i = 0; i < T_BLOCKSIZE; i++)
 122                 sum += ((unsigned char *)(&(t->th_buf)))[i];
 123         for (i = 0; i < 8; i++)
 124                 sum += (' ' - (unsigned char)t->th_buf.chksum[i]);
 125
 126         return sum;
 127 }
 128
 129
 130 /* calculate a signed header checksum */
 131 int
 132 th_signed_crc_calc(TAR *t)
 133 {
 134         int i, sum = 0;
 135
 136         for (i = 0; i < T_BLOCKSIZE; i++)
 137                 sum += ((signed char *)(&(t->th_buf)))[i];
 138         for (i = 0; i < 8; i++)
 139                 sum += (' ' - (signed char)t->th_buf.chksum[i]);
 140
 141         return sum;
 142 }
 143
 144
 145 /* string-octal to integer conversion */
 146 int
 147 oct_to_int(char *oct)
 148 {
 149         int i;
 150
 151         return sscanf(oct, "%o", &i) == 1 ? i : 0;
 152 }
 153
 154
 155 /* integer to string-octal conversion, no NULL */
 156 void
 157 int_to_oct_nonull(int num, char *oct, size_t octlen)
 158 {
 159         snprintf(oct, octlen, "%*lo", octlen - 1, (unsigned long)num);
 160         oct[octlen - 1] = ' ';
 161 }
 162
 163