src/lib/utils.c

   1 #include <stdlib.h>
   2 #include <stdio.h>
   3 #include <string.h>
   4
   5 char *
   6 utils_strsep(char **stringp, const char *delim)
   7 {
   8         char *original;
   9         char *strptr;
  10
  11         if (*stringp == NULL) {
  12                 return NULL;
  13         }
  14
  15         original = *stringp;
  16         strptr = strstr(*stringp, delim);
  17         if (strptr == NULL) {
  18                 *stringp = NULL;
  19                 return original;
  20         }
  21         *strptr = '\0';
  22         *stringp = strptr+strlen(delim);
  23         return original;
  24 }
  25
  26 int
  27 utils_read_file(char **dst, const char *filename)
  28 {
  29         FILE *stream;
  30         int filesize;
  31         char *buffer;
  32         int read_bytes;
  33
  34         /* Open stream for reading */
  35         stream = fopen(filename, "rb");
  36         if (!stream) {
  37                 return -1;
  38         }
  39
  40         /* Find out file size */
  41         fseek(stream, 0, SEEK_END);
  42         filesize = ftell(stream);
  43         fseek(stream, 0, SEEK_SET);
  44
  45         /* Allocate one extra byte for zero */
  46         buffer = malloc(filesize+1);
  47         if (!buffer) {
  48                 fclose(stream);
  49                 return -2;
  50         }
  51
  52         /* Read data in a loop to buffer */
  53         read_bytes = 0;
  54         do {
  55                 int ret = fread(buffer+read_bytes, 1,
  56                                 filesize-read_bytes, stream);
  57                 if (ret == 0) {
  58                         break;
  59                 }
  60                 read_bytes += ret;
  61         } while (read_bytes < filesize);
  62
  63         /* Add final null byte and close stream */
  64         buffer[read_bytes] = '\0';
  65         fclose(stream);
  66
  67         /* If read didn't finish, return error */
  68         if (read_bytes != filesize) {
  69                 free(buffer);
  70                 return -3;
  71         }
  72
  73         /* Return buffer */
  74         *dst = buffer;
  75         return filesize;
  76 }
  77
  78 int
  79 utils_hwaddr_raop(char *str, int strlen, const char *hwaddr, int hwaddrlen)
  80 {
  81         int i,j;
  82
  83         /* Check that our string is long enough */
  84         if (strlen == 0 || strlen < 2*hwaddrlen+1)
  85                 return -1;
  86
  87         /* Convert hardware address to hex string */
  88         for (i=0,j=0; i<hwaddrlen; i++) {
  89                 int hi = (hwaddr[i]>>4) & 0x0f;
  90                 int lo = hwaddr[i] & 0x0f;
  91
  92                 if (hi < 10) str[j++] = '0' + hi;
  93                 else         str[j++] = 'A' + hi-10;
  94                 if (lo < 10) str[j++] = '0' + lo;
  95                 else         str[j++] = 'A' + lo-10;
  96         }
  97
  98         /* Add string terminator */
  99         str[j++] = '\0';
 100         return j;
 101 }
 102
 103 int
 104 utils_hwaddr_airplay(char *str, int strlen, const char *hwaddr, int hwaddrlen)
 105 {
 106         int i,j;
 107
 108         /* Check that our string is long enough */
 109         if (strlen == 0 || strlen < 2*hwaddrlen+hwaddrlen)
 110                 return -1;
 111
 112         /* Convert hardware address to hex string */
 113         for (i=0,j=0; i<hwaddrlen; i++) {
 114                 int hi = (hwaddr[i]>>4) & 0x0f;
 115                 int lo = hwaddr[i] & 0x0f;
 116
 117                 if (hi < 10) str[j++] = '0' + hi;
 118                 else         str[j++] = 'a' + hi-10;
 119                 if (lo < 10) str[j++] = '0' + lo;
 120                 else         str[j++] = 'a' + lo-10;
 121
 122                 str[j++] = ':';
 123         }
 124
 125         /* Add string terminator */
 126         if (j != 0) j--;
 127         str[j++] = '\0';
 128         return j;
 129 }
 130