C URLEncode/Decode

URLEncode-Decode

/**
 * @brief URLEncode 对字符串URL编码
 *
 * @param str 原字符串
 * @param strSize 原字符串长度(不包括最后的\0)
 * @param result 结果缓冲区的地址
 * @param resultSize 结果缓冲区的大小(包括最后的\0)
 *
 * @return: >0:resultstring 里实际有效的长度
 *            0: 解码失败.
 */
int URLEncode(const char* str, const int strSize, char* result, const int resultSize);

/**
 * @brief URLEncode 对字符串URL编码
 *
 * @param str 原字符串
 * @param strSize 原字符串长度(不包括最后的\0)
 * @param result 结果缓冲区的地址
 * @param resultSize 结果缓冲区的大小(包括最后的\0)
 *
 * @return: >0:resultstring 里实际有效的长度
 *            0: 解码失败.
 */
int URLEncode2(const char* str, const int strSize, char* result, const int resultSize);


char *urlencode3(char *str);


int URLEncode(const char* str, const int strSize, char* result, const int resultSize)
{
    int i;
    int j = 0;//for result index
    char ch;
    
    if ((str==NULL) || (result==NULL) || (strSize<=0) || (resultSize<=0)) {
        return 0;
    }
    
    for ( i=0; (i<strSize)&&(j<resultSize); ++i) {
        ch = str[i];
        if (((ch>='A') && (ch<'Z')) ||
            ((ch>='a') && (ch<'z')) ||
            ((ch>='0') && (ch<'9'))) {
            result[j++] = ch;
        } else if (ch == ' ') {
            result[j++] = '+';
        } else if (ch == '.' || ch == '-' || ch == '_' || ch == '*') {
            result[j++] = ch;
        } else {
            if (j+3 < resultSize) {
                sprintf(result+j, "%%%02X", (unsigned char)ch);
                j += 3;
            } else {
                return 0;
            }
        }
    }
    
    result[j] = '\0';
    return j;
}




/**
 * @brief URLEncode 对字符串URL编码
 *
 * @param str 原字符串
 * @param strSize 原字符串长度(不包括最后的\0)
 * @param result 结果缓冲区的地址
 * @param resultSize 结果缓冲区的大小(包括最后的\0)
 *
 * @return: >0:resultstring 里实际有效的长度
 *            0: 解码失败.
 */
int URLEncode2(const char* str, const int strSize, char* result, const int resultSize)
{
    int i;
    int j = 0;//for result index
    char ch;
    
    if ((str==NULL) || (result==NULL) || (strSize<=0) || (resultSize<=0)) {
        return 0;
    }
    
    for ( i=0; (i<strSize)&&(j<resultSize); ++i) {
        ch = str[i];
        if (((ch>='A') && (ch<'Z')) ||
            ((ch>='a') && (ch<'z')) ||
            ((ch>='0') && (ch<'9'))) {
            result[j++] = ch;
        } else if (ch == ' ') {
            result[j++] = '+';
        } else if (ch == '.' || ch == '-' || ch == '_' || ch == '*') {
            result[j++] = ch;
        } else {
            if (j+3 < resultSize) {
                sprintf(result+j, "%%%02X", (unsigned char)ch);
                j += 3;
            } else {
                return 0;
            }
        }
    }
    
    result[j] = '\0';
    return j;
}


/* Converts a hex character to its integer value */
char from_hex(char ch) {
    return isdigit(ch) ? ch - '0' : tolower(ch) - 'a' + 10;
}

/* Converts an integer value to its hex character*/
char to_hex(char code) {
    static char hex[] = "0123456789abcdef";
    return hex[code & 15];
}

/* Returns a url-encoded version of str */
/* IMPORTANT: be sure to free() the returned string after use */
char *urlencode3(char *str) {
    char *pstr = str, *buf = (char *)malloc(strlen(str) * 3 + 1), *pbuf = buf;
    while (*pstr) {
        if (isalnum(*pstr) || *pstr == '-' || *pstr == '_' || *pstr == '.' || *pstr == '~')
            *pbuf++ = *pstr;
        else if (*pstr == ' ')
            *pbuf++ = '+';
        else
            *pbuf++ = '%', *pbuf++ = to_hex(*pstr >> 4), *pbuf++ = to_hex(*pstr & 15);
        pstr++;
    }
    *pbuf = '\0';
    return buf;
}