getlogin

getlogin

Determine User Login Name

Portability: POSIX.1 conforming, UNIX compatible

SYNOPSIS
DESCRIPTION
RETURN VALUE
EXAMPLE
RELATED FUNCTIONS
SEE ALSO

SYNOPSIS

#include <unistd.h>

char *getlogin(void);

DESCRIPTION

getlogin returns the login name for the current process. Under USS OS/390, this is the same as the userid defined for the batch job or TSO session that generated the process. The name string is stored in a static area and may be overwritten by subsequent calls to getlogin . The getlogin function fails if USS is not active or installed.

RETURN VALUE

getlogin returns a pointer to the name string if successful, and a NULL pointer if unsuccessful.

EXAMPLE

This example tests to see if the effective user ID is the ID belonging to the login name.

#include <sys/types.h>
#include <unistd.h>
#include <pwd.h>
#include <stdio.h>
#include <stdlib.h>

main() {
   char *name;
   struct passwd *unifo;

   name = getlogin();
   if (!name) {
      perror("getlogin failure");
      exit(EXIT_FAILURE);
   }
   unifo = getpwnam(name);
   if (!unifo) {
      perror("getpwnam failure");
      exit(EXIT_FAILURE);
   }
   if (unifo->pw_uid == geteuid())
      puts("Your user ID number matches the effective user ID.");
   else
      puts("Your user ID does not match the effective user ID.");
   exit(EXIT_SUCCESS);
}

RELATED FUNCTIONS

cuserid