diff options
Diffstat (limited to 'sysdeps/unix/getlogin_r.c')
-rw-r--r-- | sysdeps/unix/getlogin_r.c | 80 |
1 files changed, 80 insertions, 0 deletions
diff --git a/sysdeps/unix/getlogin_r.c b/sysdeps/unix/getlogin_r.c new file mode 100644 index 0000000..15afdee --- /dev/null +++ b/sysdeps/unix/getlogin_r.c @@ -0,0 +1,80 @@ +/* Reentrant function to return the current login name. Unix version. +Copyright (C) 1991, 1992, 1996 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 Library General Public License as +published by the Free Software Foundation; either version 2 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 +Library General Public License for more details. + +You should have received a copy of the GNU Library General Public +License along with the GNU C Library; see the file COPYING.LIB. If +not, write to the Free Software Foundation, Inc., 675 Mass Ave, +Cambridge, MA 02139, USA. */ + +#include <errno.h> +#include <unistd.h> +#include <string.h> +#include <stdio.h> +#include <limits.h> +#include <fcntl.h> + +#include <utmp.h> + +/* Return at most NAME_LEN characters of the login name of the user in NAME. + If it cannot be determined or some other error occured, return the error + code. Otherwise return 0. */ + +int +getlogin_r (name, name_len) + char *name; + size_t name_len; +{ + char tty_pathname[2 + 2 * NAME_MAX]; + char *real_tty_path = tty_pathname; + int result = 0; + struct utmp_data utmp_data; + struct utmp *ut; + + { + int err; + int d = __open ("/dev/tty", 0); + if (d < 0) + return errno; + + result = ttyname_r (d, real_tty_path, sizeof (tty_pathname)); + err = errno; + (void) close (d); + + if (result < 0) + { + errno = err; + return err; + } + } + + real_tty_path += 5; /* Remove "/dev/". */ + + setutent_r (&utmp_data); + if (getutline_r (real_tty_path, &ut, &utmp_data) < 0) + { + if (errno == ESRCH) + /* The caller expects ENOENT if nothing is found. */ + result = ENOENT; + else + result = errno; + } + else + { + strncpy (name, ut->ut_line, name_len); + result = 0; + } + endutent_r (&utmp_data); + + return result; +} |