source: Daodan/src/inifile_reader.c@ 599

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <ctype.h>

#include "inifile.h"

char* inifile_cleanstr(char* str)
{
        int i;
        for (i = strlen(str) - 1; i >= 0; i --)
                if (isspace(str[i]))
                        str[i] = '\0';
                else
                        break;
        
        while (isspace(*str))
                str++;
        
        return str;
}

int64_t inifile_parseint(const char* str, bool issigned)
{
        int64_t ret = 0;
        bool neg = false;
        if (str[0] == '0' && str[1] == 'x')
        {
                int i;
                if (str[2] == '\0')
                        return 0x100000000LL;
                
                for (i = 0, str += 2; *str; i++, str++)
                {
                        if (i == 8)
                                return 0x100000000LL;
                        
                        ret <<= 4;
                        if (*str >= '0' && *str <= '9')
                                ret |= *str - '0';
                        else if (*str >= 'a' && *str <= 'f')
                                ret |= *str - 'a' + 10;
                        else if (*str >= 'A' && *str <= 'F')
                                ret |= *str - 'A' + 10;
                        else
                                return 0x100000000LL;
                }
                return ret;
        }
        else if ((*str >= '0' && *str <= '9') || (neg = (*str == '-')))
        {
                int i;
                if (neg)
                        str++;
                for (i = 0; *str; i++, str++)
                {
                        if (i == 10)
                                return 0x100000000LL;
                        else if (i == 9 && !issigned && (ret > 429496729LL || (ret == 429496729LL && *str > '5')))
                                return 0x100000000LL;
                        else if (i == 9 && issigned && (ret > 214748364LL || (ret == 214748364LL && *str > (neg ? '8' : '7'))))
                                return 0x100000000LL;
                        
                        ret *= 10;
                        if (*str >= '0' && *str <= '9')
                                ret += *str - '0';
                        else
                                return 0x100000000LL;
                }
                if (neg)
                        ret *= -1;
                return ret;
        }
        else
                return 0x100000000LL;
}

bool inifile_read(const char* filename, inifile_callback callback)
{
        FILE* fp = fopen(filename, "r");
        char* inisection = "";
        char readbuf[4096] = "";
        char* readptr;
        bool success = true;
        bool newsection = false;
        
        if (!fp)
                return inifile_cantread;
        
        while ((readptr = fgets(readbuf, sizeof(readbuf), fp))) // Loop through each line.
        {
                while (isspace(readptr[0])) // Skip whitespace.
                        readptr++;
                
                if (readptr[0] == '\0' || readptr[0] == '#' || readptr[0] == '!') // Skip empty lines and comments.
                        continue;
                else if (readptr[0] == '[' && readptr[1] != ']') // It's a section header.
                {
                        int i;
                        for (i = 2; readptr[i]; i ++) // Look for the ]
                                if (readptr[i] == ']')
                                        break;
                        
                        if (readptr[i]) // Replace with a null or crash with error.
                                readptr[i] = '\0';
                        else
                        {
                                success = false;
                                break;
                        }
                        
                        if (inisection[0])
                                free(inisection);
                        inisection = strdup(readptr + 1); // Skip the first [
                        newsection = true;
                }
                else // It's a value.
                {
                        int i;
                        int equals = 0;
                        for (i = 0; readptr[i]; i ++) // Find the =
                                if (readptr[i] == '=')
                                        equals = i;
                        
                        if (readptr[i - 1] == '\n')
                                readptr[i - 1] = '\0'; // Remove the trailing newline.
                        
                        if (equals)
                        {
                                readptr[equals] = '\0';
                                if (!callback(inisection, newsection, readptr, readptr + equals + 1)) // If the callback is false, exit.
                                        break;
                                newsection = false;
                        }
                        else // If there's no equals, crash with error.
                        {
                                success = false;
                                break;
                        }
                }
        }
        
        if (inisection[0])
                free(inisection);
        
        fclose(fp);
        return success;
}