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//
,/
和:
。 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/