Annotation of prex-old/usr/lib/libc/stdlib/setenv.c, Revision 1.1.1.1
1.1 nbrk 1: /*
2: * Copyright (c) 1987, 1993
3: * The Regents of the University of California. All rights reserved.
4: *
5: * Redistribution and use in source and binary forms, with or without
6: * modification, are permitted provided that the following conditions
7: * are met:
8: * 1. Redistributions of source code must retain the above copyright
9: * notice, this list of conditions and the following disclaimer.
10: * 2. Redistributions in binary form must reproduce the above copyright
11: * notice, this list of conditions and the following disclaimer in the
12: * documentation and/or other materials provided with the distribution.
13: * 3. Neither the name of the University nor the names of its contributors
14: * may be used to endorse or promote products derived from this software
15: * without specific prior written permission.
16: *
17: * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18: * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19: * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20: * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21: * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22: * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23: * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24: * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25: * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26: * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27: * SUCH DAMAGE.
28: */
29:
30: #include <stddef.h>
31: #include <stdlib.h>
32: #include <string.h>
33:
34: extern char **environ;
35:
36: char *__findenv(const char *, int *);
37:
38: /*
39: * setenv --
40: * Set the value of the environmental variable "name" to be
41: * "value". If rewrite is set, replace any current value.
42: */
43: int
44: setenv(name, value, rewrite)
45: const char *name;
46: const char *value;
47: int rewrite;
48: {
49: static int alloced; /* if allocated space before */
50: char *c;
51: int l_value, offset;
52:
53: if (*value == '=') /* no `=' in value */
54: ++value;
55: l_value = strlen(value);
56: if ((c = __findenv(name, &offset))) { /* find if already exists */
57: if (!rewrite)
58: return (0);
59: if ((int)strlen(c) >= l_value) { /* old larger; copy over */
60: while ( (*c++ = *value++) );
61: return (0);
62: }
63: } else { /* create new slot */
64: int cnt;
65: char **p;
66:
67: for (p = environ, cnt = 0; *p; ++p, ++cnt);
68: if (alloced) { /* just increase size */
69: environ = (char **)realloc((char *)environ,
70: (size_t)(sizeof(char *) * (cnt + 2)));
71: if (!environ)
72: return (-1);
73: }
74: else { /* get new space */
75: alloced = 1; /* copy old entries into it */
76: p = malloc((size_t)(sizeof(char *) * (cnt + 2)));
77: if (!p)
78: return (-1);
79: bcopy(environ, p, cnt * sizeof(char *));
80: environ = p;
81: }
82: environ[cnt + 1] = NULL;
83: offset = cnt;
84: }
85: for (c = (char *)name; *c && *c != '='; ++c); /* no `=' in name */
86: if (!(environ[offset] = /* name + `=' + value */
87: malloc((size_t)((int)(c - name) + l_value + 2))))
88: return (-1);
89: for (c = environ[offset]; (*c = *name++) && *c != '='; ++c);
90: for (*c++ = '='; (*c++ = *value++) != 0;);
91: return (0);
92: }
93:
94: /*
95: * unsetenv(name) --
96: * Delete environmental variable "name".
97: */
98: void
99: unsetenv(name)
100: const char *name;
101: {
102: char **p;
103: int offset;
104:
105: while (__findenv(name, &offset)) /* if set multiple times */
106: for (p = &environ[offset];; ++p)
107: if (!(*p = *(p + 1)))
108: break;
109: }
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