libbb/read_package_field.c

   1 #include <stdlib.h>
   2 #include <string.h>
   3 #include "libbb.h"
   4
   5 /*
   6  * Gets the next package field from package_buffer, seperated into the field name
   7  * and field value, it returns the int offset to the first character of the next field
   8  */
   9 int read_package_field(const char *package_buffer, char **field_name, char **field_value)
  10 {
  11         int offset_name_start = 0;
  12         int offset_name_end = 0;
  13         int offset_value_start = 0;
  14         int offset_value_end = 0;
  15         int offset = 0;
  16         int next_offset;
  17         int name_length;
  18         int value_length;
  19         int exit_flag = FALSE;
  20
  21         if (package_buffer == NULL) {
  22                 *field_name = NULL;
  23                 *field_value = NULL;
  24                 return(-1);
  25         }
  26         while (1) {
  27                 next_offset = offset + 1;
  28                 switch (package_buffer[offset]) {
  29                         case('\0'):
  30                                 exit_flag = TRUE;
  31                                 break;
  32                         case(':'):
  33                                 if (offset_name_end == 0) {
  34                                         offset_name_end = offset;
  35                                         offset_value_start = next_offset;
  36                                 }
  37                                 /* TODO: Name might still have trailing spaces if ':' isnt
  38                                  * immediately after name */
  39                                 break;
  40                         case('\n'):
  41                                 /* TODO: The char next_offset may be out of bounds */
  42                                 if (package_buffer[next_offset] != ' ') {
  43                                         exit_flag = TRUE;
  44                                         break;
  45                                 }
  46                         case('\t'):
  47                         case(' '):
  48                                 /* increment the value start point if its a just filler */
  49                                 if (offset_name_start == offset) {
  50                                         offset_name_start++;
  51                                 }
  52                                 if (offset_value_start == offset) {
  53                                         offset_value_start++;
  54                                 }
  55                                 break;
  56                 }
  57                 if (exit_flag == TRUE) {
  58                         /* Check that the names are valid */
  59                         offset_value_end = offset;
  60                         name_length = offset_name_end - offset_name_start;
  61                         value_length = offset_value_end - offset_value_start;
  62                         if (name_length == 0) {
  63                                 break;
  64                         }
  65                         if ((name_length > 0) && (value_length > 0)) {
  66                                 break;
  67                         }
  68
  69                         /* If not valid, start fresh with next field */
  70                         exit_flag = FALSE;
  71                         offset_name_start = offset + 1;
  72                         offset_name_end = 0;
  73                         offset_value_start = offset + 1;
  74                         offset_value_end = offset + 1;
  75                         offset++;
  76                 }
  77                 offset++;
  78         }
  79         if (name_length == 0) {
  80                 *field_name = NULL;
  81         } else {
  82                 *field_name = xstrndup(&package_buffer[offset_name_start], name_length);
  83         }
  84         if (value_length > 0) {
  85                 *field_value = xstrndup(&package_buffer[offset_value_start], value_length);
  86         } else {
  87                 *field_value = NULL;
  88         }
  89         return(next_offset);
  90 }
  91