Steps to reproduce:

1. Get vfs.file.get metric from HP-UX agent

Result:
Agent returns ZBX_NOTSUPPORTED: Cannot obtain file or directory name.

Expected:
Agent returns JSON strings.

About the patch:

In Linux realpath(), the resulting pathname is stored to up to a maximum of PATH_MAX bytes automatically when second argument is NULL. But in HP-UX realpath(), developer should prepare output buffer then give the pointer to second argument.

For example:

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

int
main(void)
{
        char *ptr;

        if (NULL == (ptr = realpath("/etc/passwd", NULL)))
                printf("FAIL\n");
        else
                printf("OK: %s\n", ptr);
} 

Output is "OK: /etc/passwd" in Linux but "FAIL" in HP-UX.

This code returns "OK: /etc/passwd" in HP-UX and Linux.

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

int
main(void)
{
        char *ptr;
        char resolved_name[PATH_MAX + 1];

        if (NULL == (ptr = realpath("/etc/passwd", resolved_name)))
                printf("FAIL\n");
        else
                printf("OK: %s\n", ptr);
} 

I defined output buffer array when only HP-UX in the patch because vfs.get.file key works file in Linux and Solaris.