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/*#######################################################################

# 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;

}