libbb/read_package_field.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) many different people.  If you wrote this, please
   6  * acknowledge your work.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful, but
  14  * WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
  16  * General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, write to the Free Software
  20  * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307
  21  * USA
  22  */
  23
  24 #include <stdlib.h>
  25 #include <string.h>
  26 #include "libbb.h"
  27
  28 /*
  29  * Gets the next package field from package_buffer, seperated into the field name
  30  * and field value, it returns the int offset to the first character of the next field
  31  */
  32 int read_package_field(const char *package_buffer, char **field_name, char **field_value)
  33 {
  34         int offset_name_start = 0;
  35         int offset_name_end = 0;
  36         int offset_value_start = 0;
  37         int offset_value_end = 0;
  38         int offset = 0;
  39         int next_offset;
  40         int name_length;
  41         int value_length;
  42         int exit_flag = FALSE;
  43
  44         if (package_buffer == NULL) {
  45                 *field_name = NULL;
  46                 *field_value = NULL;
  47                 return(-1);
  48         }
  49         while (1) {
  50                 next_offset = offset + 1;
  51                 switch (package_buffer[offset]) {
  52                         case('\0'):
  53                                 exit_flag = TRUE;
  54                                 break;
  55                         case(':'):
  56                                 if (offset_name_end == 0) {
  57                                         offset_name_end = offset;
  58                                         offset_value_start = next_offset;
  59                                 }
  60                                 /* TODO: Name might still have trailing spaces if ':' isnt
  61                                  * immediately after name */
  62                                 break;
  63                         case('\n'):
  64                                 /* TODO: The char next_offset may be out of bounds */
  65                                 if (package_buffer[next_offset] != ' ') {
  66                                         exit_flag = TRUE;
  67                                         break;
  68                                 }
  69                         case('\t'):
  70                         case(' '):
  71                                 /* increment the value start point if its a just filler */
  72                                 if (offset_name_start == offset) {
  73                                         offset_name_start++;
  74                                 }
  75                                 if (offset_value_start == offset) {
  76                                         offset_value_start++;
  77                                 }
  78                                 break;
  79                 }
  80                 if (exit_flag == TRUE) {
  81                         /* Check that the names are valid */
  82                         offset_value_end = offset;
  83                         name_length = offset_name_end - offset_name_start;
  84                         value_length = offset_value_end - offset_value_start;
  85                         if (name_length == 0) {
  86                                 break;
  87                         }
  88                         if ((name_length > 0) && (value_length > 0)) {
  89                                 break;
  90                         }
  91
  92                         /* If not valid, start fresh with next field */
  93                         exit_flag = FALSE;
  94                         offset_name_start = offset + 1;
  95                         offset_name_end = 0;
  96                         offset_value_start = offset + 1;
  97                         offset_value_end = offset + 1;
  98                         offset++;
  99                 }
 100                 offset++;
 101         }
 102         if (name_length == 0) {
 103                 *field_name = NULL;
 104         } else {
 105                 *field_name = xstrndup(&package_buffer[offset_name_start], name_length);
 106         }
 107         if (value_length > 0) {
 108                 *field_value = xstrndup(&package_buffer[offset_value_start], value_length);
 109         } else {
 110                 *field_value = NULL;
 111         }
 112         return(next_offset);
 113 }
 114