Why is the following regex not working in C using regcomp

问题

I have the following regex to match the last pair of braces in a string,

.+(?={)(.+)(?=})

The example string is,

abc{abc=bcd}{gef=hij}

I want the contents within the last braces (gef=hij) inside the captured group. This works in a regex tester available in the web

http://regexpal.com/

When I use regcomp to compile the same regex, it doesnt. Any ideas?

int reti = regcomp(&regex, ".+(?={)(.+)(?=})", REG_EXTENDED);
if (reti) {
    fprintf(stderr, "Could not compile regex\n");
    exit(1);
}

回答1:

Anyway, regcomp uses POSIX BRE or ERE, which doesn't support look-ahead or look-behind.

.+{(.+)}

Grab the string you want from group index 1.

DEMO

回答2:

Uses an anchor to specify the pattern should match when at the end of a line.

(?<=[{]).*(?=[}]$)

来源：https://stackoverflow.com/questions/27188328/why-is-the-following-regex-not-working-in-c-using-regcomp