src/lib/utils.c

   1 /**
   2  *  Copyright (C) 2011-2012  Juho Vähä-Herttua
   3  *
   4  *  This library is free software; you can redistribute it and/or
   5  *  modify it under the terms of the GNU Lesser General Public
   6  *  License as published by the Free Software Foundation; either
   7  *  version 2.1 of the License, or (at your option) any later version.
   8  *
   9  *  This library is distributed in the hope that it will be useful,
  10  *  but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  *  Lesser General Public License for more details.
  13  */
  14
  15 #include <stdlib.h>
  16 #include <stdio.h>
  17 #include <string.h>
  18
  19 char *
  20 utils_strsep(char **stringp, const char *delim)
  21 {
  22         char *original;
  23         char *strptr;
  24
  25         if (*stringp == NULL) {
  26                 return NULL;
  27         }
  28
  29         original = *stringp;
  30         strptr = strstr(*stringp, delim);
  31         if (strptr == NULL) {
  32                 *stringp = NULL;
  33                 return original;
  34         }
  35         *strptr = '\0';
  36         *stringp = strptr+strlen(delim);
  37         return original;
  38 }
  39
  40 int
  41 utils_read_file(char **dst, const char *filename)
  42 {
  43         FILE *stream;
  44         int filesize;
  45         char *buffer;
  46         int read_bytes;
  47
  48         /* Open stream for reading */
  49         stream = fopen(filename, "rb");
  50         if (!stream) {
  51                 return -1;
  52         }
  53
  54         /* Find out file size */
  55         fseek(stream, 0, SEEK_END);
  56         filesize = ftell(stream);
  57         fseek(stream, 0, SEEK_SET);
  58
  59         /* Allocate one extra byte for zero */
  60         buffer = malloc(filesize+1);
  61         if (!buffer) {
  62                 fclose(stream);
  63                 return -2;
  64         }
  65
  66         /* Read data in a loop to buffer */
  67         read_bytes = 0;
  68         do {
  69                 int ret = fread(buffer+read_bytes, 1,
  70                                 filesize-read_bytes, stream);
  71                 if (ret == 0) {
  72                         break;
  73                 }
  74                 read_bytes += ret;
  75         } while (read_bytes < filesize);
  76
  77         /* Add final null byte and close stream */
  78         buffer[read_bytes] = '\0';
  79         fclose(stream);
  80
  81         /* If read didn't finish, return error */
  82         if (read_bytes != filesize) {
  83                 free(buffer);
  84                 return -3;
  85         }
  86
  87         /* Return buffer */
  88         *dst = buffer;
  89         return filesize;
  90 }
  91
  92 int
  93 utils_hwaddr_raop(char *str, int strlen, const char *hwaddr, int hwaddrlen)
  94 {
  95         int i,j;
  96
  97         /* Check that our string is long enough */
  98         if (strlen == 0 || strlen < 2*hwaddrlen+1)
  99                 return -1;
 100
 101         /* Convert hardware address to hex string */
 102         for (i=0,j=0; i<hwaddrlen; i++) {
 103                 int hi = (hwaddr[i]>>4) & 0x0f;
 104                 int lo = hwaddr[i] & 0x0f;
 105
 106                 if (hi < 10) str[j++] = '0' + hi;
 107                 else         str[j++] = 'A' + hi-10;
 108                 if (lo < 10) str[j++] = '0' + lo;
 109                 else         str[j++] = 'A' + lo-10;
 110         }
 111
 112         /* Add string terminator */
 113         str[j++] = '\0';
 114         return j;
 115 }
 116
 117 int
 118 utils_hwaddr_airplay(char *str, int strlen, const char *hwaddr, int hwaddrlen)
 119 {
 120         int i,j;
 121
 122         /* Check that our string is long enough */
 123         if (strlen == 0 || strlen < 2*hwaddrlen+hwaddrlen)
 124                 return -1;
 125
 126         /* Convert hardware address to hex string */
 127         for (i=0,j=0; i<hwaddrlen; i++) {
 128                 int hi = (hwaddr[i]>>4) & 0x0f;
 129                 int lo = hwaddr[i] & 0x0f;
 130
 131                 if (hi < 10) str[j++] = '0' + hi;
 132                 else         str[j++] = 'a' + hi-10;
 133                 if (lo < 10) str[j++] = '0' + lo;
 134                 else         str[j++] = 'a' + lo-10;
 135
 136                 str[j++] = ':';
 137         }
 138
 139         /* Add string terminator */
 140         if (j != 0) j--;
 141         str[j++] = '\0';
 142         return j;
 143 }
 144