1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
|
/*
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.
<<getenv>> requires a global pointer <<environ>>.
*/
/* This file may have been modified by DJ Delorie (Jan 1991). If so,
** these modifications are Coyright (C) 1991 DJ Delorie, 24 Kirsten Ave,
** Rochester NH, 03867-2954, USA.
*/
/*
* Copyright (c) 1987 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
* and in all advertising materials mentioning features or use of this
* software. 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.
*/
#include <stdlib.h>
#include <stddef.h>
#include <string.h>
extern char **environ;
/*
* _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 *
_DEFUN (_findenv, (name, offset),
register _CONST char *name _AND
int *offset)
{
register int len;
register char **p;
_CONST char *c;
/* In some embedded systems, this does not get set. This protects
newlib from dereferencing a bad pointer. */
if (!environ)
return NULL;
c = name;
len = 0;
while (*c && *c != '=')
{
c++;
len++;
}
for (p = environ; *p; ++p)
if (!strncmp (*p, name, len))
if (*(c = *p + len) == '=')
{
*offset = p - environ;
return (char *) (++c);
}
return NULL;
}
/*
* getenv --
* Returns ptr to value associated with name, if any, else NULL.
*/
char *
_DEFUN (getenv, (name),
_CONST char *name)
{
int offset;
char *_findenv ();
return _findenv (name, &offset);
}
|
