newlib-cygwin/newlib/libc/stdlib/getenv.c

86 lines
2.3 KiB
C

/*
FUNCTION
<<getenv>>---look up environment variable
INDEX
getenv
INDEX
environ
SYNOPSIS
#include <stdlib.h>
char *getenv(const 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.
<<getenv>> requires a global pointer <<environ>>.
*/
/*
* Copyright (c) 1987, 2000 Regents of the University of California.
* All rights reserved.
*
* Redistribution and use in source and binary forms are permitted
* provided that: (1) source distributions retain this entire copyright
* notice and comment, and (2) distributions including binaries display
* the following acknowledgement: ``This product includes software
* developed by the University of California, Berkeley and its contributors''
* in the documentation or other materials provided with the distribution.
* Neither the name of the University nor the names of its
* contributors may be used to endorse or promote products derived
* from this software without specific prior written permission.
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR
* IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.
*/
#ifndef _REENT_ONLY
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
/*
* _findenv --
* Returns pointer to value associated with name, if any, else NULL.
* Sets offset to be the offset of the name/value combination in the
* environmental array, for use by setenv(3) and unsetenv(3).
* Explicitly removes '=' in argument name.
*
* This routine *should* be a static; don't use it.
*/
char *
_findenv (register const char *name,
int *offset)
{
return _findenv_r (_REENT, name, offset);
}
/*
* getenv --
* Returns ptr to value associated with name, if any, else NULL.
*/
char *
getenv (const char *name)
{
int offset;
return _findenv_r (_REENT, name, &offset);
}
#endif /* !_REENT_ONLY */