79 lines
2.2 KiB
C
79 lines
2.2 KiB
C
/*#######################################################################
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# RDOS operating system
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# Copyright (C) 1988-2006, Leif Ekblad
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#
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# This library is free software; you can redistribute it and/or modify
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# it under the terms of the GNU Lesser General Public License as published
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# by the Free Software Foundation; either version 2.1 of the License, or
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# (at your option) any later version.
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#
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# This library is distributed in the hope that it will be useful,
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# but WITHOUT ANY WARRANTY; without even the implied warranty of
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# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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# GNU Lesser General Public License for more details.
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#
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# You should have received a copy of the GNU Lesser General Public
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# License along with this library; if not, write to the Free Software
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# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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#
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# The author of this program may be contacted at leif@rdos.net
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#
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# getenv.c
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# getenv function implementation
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#
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##########################################################################*/
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/*
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FUNCTION
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<<getenv>>---look up environment variable
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INDEX
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getenv
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INDEX
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environ
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SYNOPSIS
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#include <stdlib.h>
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char *getenv(const char *<[name]>);
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DESCRIPTION
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<<getenv>> searches the list of environment variable names and values
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(using the global pointer ``<<char **environ>>'') for a variable whose
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name matches the string at <[name]>. If a variable name matches,
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<<getenv>> returns a pointer to the associated value.
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RETURNS
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A pointer to the (string) value of the environment variable, or
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<<NULL>> if there is no such environment variable.
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PORTABILITY
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<<getenv>> is ANSI, but the rules for properly forming names of environment
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variables vary from one system to another.
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This function is not thread-safe, but does it need to be??
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There is an reentrant class that should be used if reentrance is required
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*/
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#include <stdlib.h>
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#include <stddef.h>
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#include <string.h>
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#include <rdos.h>
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static char envbuf[256];
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char *getenv(const char *name)
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{
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int handle;
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char *ptr = 0;
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handle = RdosOpenSysEnv();
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if (handle)
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{
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if (RdosFindEnvVar(handle, name, envbuf))
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ptr = envbuf;
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}
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RdosCloseEnv(handle);
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return ptr;
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}
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