我试图遍历C中的输入参数,该参数存储在指向char的指针中,如下所示:const char *page = argv[1];

现在,该参数将是一个http地址,因此它可能看起来像这样:

http://host:port/folder1/folder2/file.jpg

我想要的是:解析此字符串并将其分离为子字符串

char host = "host";
char port = "port";
char path = "/folder1/folder2/file.jpg";
char file = "file.jpg";


因此,我认为使用简单的for循环计数斜杠数量可能会达到目的。

int slash_cnt = 0;
int i = 0;

for (i = 0, page[i] != '\0', i++)
{
    if (strcmp(&page[i], "/"))
    {
        slash_cnt++;
    }
}


但这是行不通的。

如果有人可以在这里为我提供帮助,或者甚至提出一种更好的方法来解析输入中指定的http地址并相应地将其分开,我将不胜感激!

最佳答案

strstr可用于搜索分隔感兴趣部分的字符串///:strrchr可用于查找文件名之前的尾随/

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

int main()
{
    char *page = "http://host:port/folder1/folder2/file.jpg";
    char *slashes = "//";
    char *slash = "/";
    char *colon = ":";
    char *start = NULL;
    char *stop = NULL;
    char *host = NULL;
    char *port = NULL;
    char *path = NULL;
    char *file = NULL;
    size_t span = 0;

    if ( ( start = strstr ( page, slashes)) == NULL) {
        fputs ( "could not find \"//\"\n", stderr);
        return 1;
    }
    start += strlen ( slashes);//move pointer so the slashes are excluded
    if ( ( stop = strstr ( start, colon)) == NULL) {
        fputs ( "could not find \":\"\n", stderr);
        return 1;
    }
    span = stop - start;
    if ( ( host = malloc ( span)) == NULL) {
        fputs ( "malloc failed\n", stderr);
        return 1;
    }
    memmove ( host, start, span);
    host[span] = '\0';

    start = stop + strlen ( colon);
    if ( ( stop = strstr ( start, slash)) == NULL) {
        fputs ( "could not find leading \"/\"\n", stderr);
        return 1;
    }
    span = stop - start;
    if ( ( port = malloc ( span)) == NULL) {
        fputs ( "malloc failed\n", stderr);
        return 1;
    }
    memmove ( port, start, span);
    port[span] = '\0';

    span = strlen ( stop) + 1;
    if ( ( path = malloc ( span)) == NULL) {
        fputs ( "malloc failed\n", stderr);
        return 1;
    }
    memmove ( path, stop, span);
    path[span] = '\0';

    if ( ( start = strrchr ( page, slash[0])) == NULL) {
        fputs ( "could not find trailing \"/\"\n", stderr);
        return 1;
    }
    start += strlen ( slash);
    span = strlen ( start) + 1;
    if ( ( file = malloc ( span)) == NULL) {
        fputs ( "malloc failed\n", stderr);
        return 1;
    }
    memmove ( file, start, span);
    file[span] = '\0';

    puts ( host);
    puts ( port);
    puts ( path);
    puts ( file);

    free ( host);
    free ( port);
    free ( path);
    free ( file);

    return 0;
}

关于c - 通过C中的输入char参数进行迭代?,我们在Stack Overflow上找到一个类似的问题:https://stackoverflow.com/questions/42747601/

10-11 22:39
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