Posix正前pression非贪婪 [英] Posix regular expression non-greedy

问题描述

有没有使用非正规贪婪前pression用C一样可以在Perl中使用的方法吗？
我试了几件事情，但它实际上没有工作。

Is there a way to use a non-greedy regular expression in C like one can use in Perl? I tried several things, but it's actually not working.

我目前使用此正则表达式匹配的IP地址和相应的HTTP请求，但尽管我使用的是贪婪的*？：

I'm currently using this regex that matches an IP address and the corresponding HTTP request, but it's greedy although I'm using the *?:

（[0-9] {1,3}（\\\\。[0-9] {1,3}）{3}）（。*？）HTTP / 1.1

在这个例子中，它总是整个字符串匹配

In this example, it always matches the whole string:

#include <regex.h>
#include <stdio.h>

int main() {

    int a, i;
    regex_t re;
    regmatch_t pm;
    char *mpages = "TEST 127.0.0.1 GET /test.php HTTP/1.1\" 404 525 \"-\" \"Mozilla/5.0 (Windows NT  HTTP/1.1 TEST";

    a = regcomp(&re, "([0-9]{1,3}(\\.[0-9]{1,3}){3})(.*?)HTTP/1.1", REG_EXTENDED);

    if(a!=0)
        printf(" -> Error: Invalid Regex");

    a = regexec(&re, &mpages[0], 1, &pm, REG_EXTENDED);

    if(a==0) {

        for(i = pm.rm_so; i < pm.rm_eo; i++)
            printf("%c", mpages[i]);
        printf("\n");
    }
    return 0;
}

$ ./regtest

$ ./regtest

127.0.0.1 GET /test.php HTTP / 1.1404 525 - Mozilla的/ 5.0（Windows NT的HTTP / 1.1

127.0.0.1 GET /test.php HTTP/1.1" 404 525 "-" "Mozilla/5.0 (Windows NT HTTP/1.1

推荐答案

没有，也有POSIX正前pressions没有非贪婪量词。但它提供的perl-像普通的前pressions对于C库： http://www.pcre.org /

No, there are no non-greedy quantifiers in POSIX regular expressions. But there is a library that provides perl-like regular expressions for C: http://www.pcre.org/

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