rework langinfo code for ABI compat and for use by time code

[musl] / src / misc / dirname.c

#include <string.h>
#include <libgen.h>

char *dirname(char *s)
{
        size_t i;
        if (!s || !*s) return ".";
        i = strlen(s)-1;
        for (; s[i]=='/'; i--) if (!i) return "/";
        for (; s[i]!='/'; i--) if (!i) return ".";
        for (; s[i]=='/'; i--) if (!i) return "/";
        s[i+1] = 0;
        return s;
}