libbb/read_package_field.c

   1 /* vi: set sw=4 ts=4: */
   2 /*
   3  * Utility routines.
   4  *
   5  * Copyright (C) many different people.
   6  * If you wrote this, please acknowledge your work.
   7  *
   8  * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
   9  */
  10
  11 #include <stdlib.h>
  12 #include <string.h>
  13 #include "libbb.h"
  14
  15 /*
  16  * Gets the next package field from package_buffer, seperated into the field name
  17  * and field value, it returns the int offset to the first character of the next field
  18  */
  19 int read_package_field(const char *package_buffer, char **field_name, char **field_value)
  20 {
  21         int offset_name_start = 0;
  22         int offset_name_end = 0;
  23         int offset_value_start = 0;
  24         int offset_value_end = 0;
  25         int offset = 0;
  26         int next_offset;
  27         int name_length;
  28         int value_length;
  29         int exit_flag = FALSE;
  30
  31         if (package_buffer == NULL) {
  32                 *field_name = NULL;
  33                 *field_value = NULL;
  34                 return(-1);
  35         }
  36         while (1) {
  37                 next_offset = offset + 1;
  38                 switch (package_buffer[offset]) {
  39                         case('\0'):
  40                                 exit_flag = TRUE;
  41                                 break;
  42                         case(':'):
  43                                 if (offset_name_end == 0) {
  44                                         offset_name_end = offset;
  45                                         offset_value_start = next_offset;
  46                                 }
  47                                 /* TODO: Name might still have trailing spaces if ':' isnt
  48                                  * immediately after name */
  49                                 break;
  50                         case('\n'):
  51                                 /* TODO: The char next_offset may be out of bounds */
  52                                 if (package_buffer[next_offset] != ' ') {
  53                                         exit_flag = TRUE;
  54                                         break;
  55                                 }
  56                         case('\t'):
  57                         case(' '):
  58                                 /* increment the value start point if its a just filler */
  59                                 if (offset_name_start == offset) {
  60                                         offset_name_start++;
  61                                 }
  62                                 if (offset_value_start == offset) {
  63                                         offset_value_start++;
  64                                 }
  65                                 break;
  66                 }
  67                 if (exit_flag) {
  68                         /* Check that the names are valid */
  69                         offset_value_end = offset;
  70                         name_length = offset_name_end - offset_name_start;
  71                         value_length = offset_value_end - offset_value_start;
  72                         if (name_length == 0) {
  73                                 break;
  74                         }
  75                         if ((name_length > 0) && (value_length > 0)) {
  76                                 break;
  77                         }
  78
  79                         /* If not valid, start fresh with next field */
  80                         exit_flag = FALSE;
  81                         offset_name_start = offset + 1;
  82                         offset_name_end = 0;
  83                         offset_value_start = offset + 1;
  84                         offset_value_end = offset + 1;
  85                         offset++;
  86                 }
  87                 offset++;
  88         }
  89         if (name_length == 0) {
  90                 *field_name = NULL;
  91         } else {
  92                 *field_name = bb_xstrndup(&package_buffer[offset_name_start], name_length);
  93         }
  94         if (value_length > 0) {
  95                 *field_value = bb_xstrndup(&package_buffer[offset_value_start], value_length);
  96         } else {
  97                 *field_value = NULL;
  98         }
  99         return(next_offset);
 100 }
 101