glibc/sysdeps/posix/cuserid.c

49 lines
1.5 KiB
C

/* Copyright (C) 1991, 1996, 1998, 1999, 2001 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 of the License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; if not, write to the Free
Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA. */
#include <pwd.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <sys/types.h>
/* Return the username of the caller.
If S is not NULL, it points to a buffer of at least L_cuserid bytes
into which the name is copied; otherwise, a static buffer is used. */
char *
cuserid (s)
char *s;
{
static char name[L_cuserid];
char buf[NSS_BUFLEN_PASSWD];
struct passwd pwent;
struct passwd *pwptr;
if (__getpwuid_r (__geteuid (), &pwent, buf, sizeof (buf), &pwptr)
|| pwptr == NULL)
{
if (s != NULL)
s[0] = '\0';
return s;
}
if (s == NULL)
s = name;
return strncpy (s, pwptr->pw_name, L_cuserid);
}