84 lines
2.3 KiB
C
84 lines
2.3 KiB
C
/*#######################################################################
|
|
# RDOS operating system
|
|
# Copyright (C) 1988-2006, Leif Ekblad
|
|
#
|
|
# This 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.
|
|
#
|
|
# This 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 this library; if not, write to the Free Software
|
|
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
|
|
#
|
|
# The author of this program may be contacted at leif@rdos.net
|
|
#
|
|
# getenv.c
|
|
# getenv function implementation
|
|
#
|
|
##########################################################################*/
|
|
|
|
/*
|
|
FUNCTION
|
|
<<getenv>>---look up environment variable
|
|
|
|
INDEX
|
|
getenv
|
|
INDEX
|
|
environ
|
|
|
|
ANSI_SYNOPSIS
|
|
#include <stdlib.h>
|
|
char *getenv(const char *<[name]>);
|
|
|
|
TRAD_SYNOPSIS
|
|
#include <stdlib.h>
|
|
char *getenv(<[name]>)
|
|
char *<[name]>;
|
|
|
|
DESCRIPTION
|
|
<<getenv>> searches the list of environment variable names and values
|
|
(using the global pointer ``<<char **environ>>'') for a variable whose
|
|
name matches the string at <[name]>. If a variable name matches,
|
|
<<getenv>> returns a pointer to the associated value.
|
|
|
|
RETURNS
|
|
A pointer to the (string) value of the environment variable, or
|
|
<<NULL>> if there is no such environment variable.
|
|
|
|
PORTABILITY
|
|
<<getenv>> is ANSI, but the rules for properly forming names of environment
|
|
variables vary from one system to another.
|
|
|
|
This function is not thread-safe, but does it need to be??
|
|
There is an reentrant class that should be used if reentrance is required
|
|
|
|
*/
|
|
|
|
#include <stdlib.h>
|
|
#include <stddef.h>
|
|
#include <string.h>
|
|
#include <rdos.h>
|
|
|
|
static char envbuf[256];
|
|
|
|
char *getenv(const char *name)
|
|
{
|
|
int handle;
|
|
char *ptr = 0;
|
|
|
|
handle = RdosOpenSysEnv();
|
|
if (handle)
|
|
{
|
|
if (RdosFindEnvVar(handle, name, envbuf))
|
|
ptr = envbuf;
|
|
}
|
|
RdosCloseEnv(handle);
|
|
return ptr;
|
|
}
|