Question

我想从我的http响应中提取Json对象。但是我怎样才能提取出来呢？

这是我的字符串：

GET /axis-cgi/dynamicoverlay.cgi?action=settext&text=HTTP/1.1 200 OK＃015＃012Server：nginx＃015＃012日期：2015年9月18日星期五09:39:01 GMT＃015＃012Content -Type：application / json; charset = utf-8＃015＃012Transfer-Encoding：chunked＃015＃012Connection：keep-alive＃015＃012X-Source：redis＃015＃012Access-Control-Allow-Origin：*＃015＃012Access-Control-Allow-证书：true＃015＃012Access-Control-Allow-Methods：GET，POST＃015＃012＃015＃0121c1＃015＃012 {＆＃34; coord＆＃34;：{＆＃34; lon＆＃34;：145.77 ＆＃34; LAT＆＃34;： - 16.92}＆＃34;天气＆＃34;：[{＆＃34; ID＆＃34; 800＆＃34;主＆＃34;：＆＃34;清除＆＃34;，＆＃34;说明＆＃34;：＆＃34;天空晴朗＆＃34;，＆＃34;图标＆＃34;：＆＃34; 01n＆＃34;}]，＆＃34;基地＆＃ 34;：＆＃34;站＆＃34;＆＃34;主＆＃34; {＆＃34;温度＆＃34;：296.49＆＃34;压力＆＃34;：1013，＆＃34;湿度＆＃ 34; 50＆＃34; temp_min＆＃34;：295.93＆＃34; temp_max＆＃34;：297.15}，＆＃34;能见度＆＃34;：10000＆＃34;风＆＃34;：{＆＃34;速度＆＃34;：2.1，＆＃34;度＆＃34;：100}＆＃34;云＆＃34; {＆＃34;所有＆＃34;：0}，＆＃34; DT＆＃ 34;：1442566613，＆＃34; SYS＆＃34; {＆＃34;类型＆＃34;：1，＆＃34; ID＆＃34;：8166，＆＃34;消息＆＃34;：0.0075，＆＃ 34;国家＆＃34;：＆＃34; AU＆＃34;＆＃34;日出＆＃34;：1442520614，＆＃34;日落＆＃34;：1442563944}＆＃34; ID＆＃34;：2172797，＆＃34;名称＆＃34;：＆＃34;凯恩斯＆＃34;＆＃34;鳕鱼＆＃34;：200}＃012＃015＃0120＃015＃012＃015＃012 HTTP / 1.0＃015＃012授权：基本cm9vdDpzdHJlYW0 =＃015＃012主机：192.168.2.3

Answer 1

在你开始反复提出同样的问题之前，这是一个解决方案：

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

/*
 *      Extracts the fist JSON object between balanced curly braces
 *      and copies it to the given buffer. Returns the length of the
 *      extracted string. At most nbuf -1 characters will be copied 
 *      and the result is always null-terminated. A return value
 *      of nbuf or higher indicates that the output aws truncated.
 *      If no object is found, -1 is returned.
 */
int get_json(char buf[], size_t nbuf, const char *str)
{
    const char *p, *q;
    int braces = 0;

    p = strchr(str, '{');
    if (p == NULL) return -1;

    for (q = p; *q; q++) {
        if (*q == '{') braces++;
        if (*q == '}') {
            braces--;

            if (braces == 0) {
                int len = q - p + 1;

                return snprintf(buf, nbuf, "%.*s", len, p);
            }
        }
    }

    return -1;      // brace mismatch;
}

int main()
{
    char *str = "GET /axis-cgi/dynamicoverlay.cgi?action=settext&"
        "text=HTTP/1.1 200 OK#015#012Server: nginx#015#01"
        "2Date: Fri, 18 Sep 2015 09:39:01 GMT#015#012Cont"
        "ent-Type: application/json; charset=utf-8#015#01"
        "2Transfer-Encoding: chunked#015#012Connection: k"
        "eep-alive#015#012X-Source: redis#015#012Access-C"
        "ontrol-Allow-Origin: *#015#012Access-Control-All"
        "ow-Credentials: true#015#012Access-Control-Allow"
        "-Methods: GET, POST#015#012#015#0121c1#015#012{\""
        "coord\":{\"lon\":145.77,\"lat\":-16.92},\"weather\":[{\""
        "id\":800,\"main\":\"Clear\",\"description\":\"Sky is Cle"
        "ar\",\"icon\":\"01n\"}],\"base\":\"stations\",\"main\":{\"te"
        "mp\":296.49,\"pressure\":1013,\"humidity\":50,\"temp_m"
        "in\":295.93,\"temp_max\":297.15},\"visibility\":10000"
        ",\"wind\":{\"speed\":2.1,\"deg\":100},\"clouds\":{\"all\":"
        "0},\"dt\":1442566613,\"sys\":{\"type\":1,\"id\":8166,\"me"
        "ssage\":0.0075,\"country\":\"AU\",\"sunrise\":144252061"
        "4,\"sunset\":1442563944},\"id\":2172797,\"name\":\"Cair"
        "ns\",\"cod\":200}#012#015#0120#015#012#015#012 HTTP"
        "/1.0#015#012Authorization: Basic cm9vdDpzdHJlYW0"
        "=#015#012Host: 192.168.2.3";
    char buf[512];
    int n;

    n = get_json(buf, sizeof(buf), str);
    if (n >= 0) puts(buf);

    return 0;
}

如何从C中的sting中提取特定字符（http响应）

1 个答案: