1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License (the "License").
6 * You may not use this file except in compliance with the License.
7 *
8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
9 * or http://www.opensolaris.org/os/licensing.
10 * See the License for the specific language governing permissions
11 * and limitations under the License.
12 *
13 * When distributing Covered Code, include this CDDL HEADER in each
14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
15 * If applicable, add the following below this CDDL HEADER, with the
16 * fields enclosed by brackets "[]" replaced with your own identifying
17 * information: Portions Copyright [yyyy] [name of copyright owner]
18 *
19 * CDDL HEADER END
20 */
21
22 /*
23 * Copyright 2008 Sun Microsystems, Inc. All rights reserved.
24 * Use is subject to license terms.
25 */
26
27 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
28 /* All Rights Reserved */
29
30 /*
31 * NAME
32 * xsetenv, xgetenv, Xgetenv - manage an alternate environment space
33 *
34 * SYNOPSIS
35 * int ret = xsetenv(file)
36 * char *x = xgetenv("FOO");
37 * char *x = Xgetenv("FOO");
38 *
39 * DESCRIPTION
40 * xsetenv() reads the given file into an internal buffer
41 * and sets up an alternate environment.
42 *
43 * Return values: 1 - OKAY
44 * 0 - troubles reading the file
45 * -1 - troubles opening the file
46 *
47 * xgetenv() returns the environment value from the
48 * alternate environment.
49 *
50 * Return values: (char *)0 - no value for that variable
51 * pointer - the value
52 *
53 * Xgetenv() returns the environment value from the
54 * alternate environment.
55 *
56 * Return values: "" - no value for that variable
57 * pointer - the value
58 *
59 * LIMITATIONS
60 * Assumes the environment is < 5120 bytes, as in the UNIX
61 * System environment. Assumes < 512 lines in the file.
62 * These values may be adjusted below.
63 */
64
65 #include <sys/types.h>
66 #include "libmail.h"
67 #include <stdio.h>
68 #include <string.h>
69 #include <fcntl.h>
70 #include <ctype.h>
71
72 #include <stdlib.h>
73 #include <unistd.h>
74
75 #define MAXVARS 512
76 #define MAXENV 5120
77
78 static char **xenv = 0;
79 static char *(xenvptrs[MAXVARS]);
80 static char xbuf[MAXENV];
81
82 static void reduce(char *);
83
84 /*
85 * set up an environment buffer
86 * and the pointers into it
87 */
88 int
xsetenv(char * xfile)89 xsetenv(char *xfile)
90 {
91 int envctr, infd;
92 ssize_t i, nread;
93
94 /* Open the file */
95 infd = open(xfile, O_RDONLY);
96 if (infd == -1) {
97 return (-1);
98 }
99
100 /* Read in the entire file. */
101 nread = read(infd, xbuf, sizeof (xbuf));
102 if (nread < 0) {
103 (void) close(infd);
104 return (0);
105 }
106
107 /*
108 * Set up pointers into the buffer.
109 * Replace \n with \0.
110 * Collapse white space around the = sign and at the
111 * beginning and end of the line.
112 */
113 xenv = xenvptrs;
114 xenv[0] = &xbuf[0];
115 for (i = 0, envctr = 0; i < nread; i++) {
116 if (xbuf[i] == '\n') {
117 xbuf[i] = '\0';
118 reduce(xenv[envctr]);
119 xenv[++envctr] = &xbuf[i+1];
120 if (envctr == MAXVARS) {
121 break;
122 }
123 }
124 }
125
126 xenv[envctr] = 0;
127 (void) close(infd);
128 return (1);
129 }
130
131 /*
132 * Let getenv() do the dirty work
133 * of looking up the variable. We
134 * do this by temporarily resetting
135 * environ to point to the local area.
136 */
137 char *
xgetenv(char * env)138 xgetenv(char *env)
139 {
140 extern char **environ;
141 char *ret, **svenviron = environ;
142
143 environ = xenv;
144 ret = getenv(env);
145 environ = svenviron;
146 return (ret);
147 }
148
149 /*
150 * Let xgetenv() do the dirty work
151 * of looking up the variable.
152 */
153 char *
Xgetenv(char * env)154 Xgetenv(char *env)
155 {
156 char *ret = xgetenv(env);
157 return (ret ? ret : "");
158 }
159
160 /*
161 * Remove the spaces within the environment variable.
162 * The variable can look like this:
163 *
164 * <sp1> variable <sp2> = <sp3> value <sp4> \0
165 *
166 * All spaces can be removed, except within
167 * the variable name and the value.
168 */
169
170 static void
reduce(char * from)171 reduce(char *from)
172 {
173 char *to = from;
174 char *svfrom = from;
175
176 /* <sp1> */
177 while (*from &&isspace((int)*from))
178 from++;
179
180 /* variable */
181 while (*from && (*from != '=') && !isspace((int)*from))
182 *to++ = *from++;
183
184 /* <sp2> */
185 while (*from && isspace((int)*from))
186 from++;
187
188 /* = */
189 if (*from == '=')
190 *to++ = *from++;
191
192 /* <sp3> */
193 while (*from && isspace((int)*from))
194 from++;
195
196 /* value */
197 while (*from)
198 *to++ = *from++;
199
200 /* <sp4> */
201 while ((to > svfrom) && isspace((int)to[-1]))
202 to--;
203 *to = '\0';
204 }
205