libcsupport/src/getlogin.c

0001 /* SPDX-License-Identifier: BSD-2-Clause */
0002
0003 /**
0004  *  @file
0005  *
0006  *  @brief Get User Name
0007  *
0008  *  @ingroup libcsupport
0009  */
0010
0011 /*
0012  * COPYRIGHT (C) 1989-1999 On-Line Applications Research Corporation (OAR).
0013  *
0014  * Redistribution and use in source and binary forms, with or without
0015  * modification, are permitted provided that the following conditions
0016  * are met:
0017  * 1. Redistributions of source code must retain the above copyright
0018  *    notice, this list of conditions and the following disclaimer.
0019  * 2. Redistributions in binary form must reproduce the above copyright
0020  *    notice, this list of conditions and the following disclaimer in the
0021  *    documentation and/or other materials provided with the distribution.
0022  *
0023  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
0024  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
0025  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
0026  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
0027  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
0028  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
0029  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
0030  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
0031  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
0032  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
0033  * POSSIBILITY OF SUCH DAMAGE.
0034  */
0035
0036 #ifdef HAVE_CONFIG_H
0037 #include "config.h"
0038 #endif
0039
0040 #include <limits.h>
0041 #include <string.h>
0042 #include <sys/types.h>
0043 #include <errno.h>
0044
0045 #include <rtems/seterr.h>
0046 #include <rtems/userenv.h>
0047
0048 #include <unistd.h>
0049 #include <pwd.h>
0050
0051 /**
0052  *  4.2.4 Get User Name, P1003.1b-1993, p. 87
0053  *
0054  *  @note P1003.1c/D10, p. 49 adds getlogin_r().
0055  */
0056 char *getlogin( void )
0057 {
0058   (void) getlogin_r( _POSIX_types_Getlogin_buffer, LOGIN_NAME_MAX );
0059   return _POSIX_types_Getlogin_buffer;
0060 }
0061
0062 /**
0063  *  4.2.4 Get User Name, P1003.1b-1993, p. 87
0064  *
0065  *  @note P1003.1c/D10, p. 49 adds getlogin_r().
0066  */
0067 int getlogin_r(
0068   char   *name,
0069   size_t  namesize
0070 )
0071 {
0072   struct passwd *pw;
0073   char          *pname;
0074
0075   if ( !name )
0076     return EFAULT;
0077
0078   if ( namesize < LOGIN_NAME_MAX )
0079     return ERANGE;
0080
0081   /* Set the pointer to a default name */
0082   pname = "";
0083
0084   pw = getpwuid(getuid());
0085   if ( pw )
0086    pname = pw->pw_name;
0087
0088   strncpy( name, pname, LOGIN_NAME_MAX );
0089   return 0;
0090 }