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 #pragma ident "%Z%%M% %I% %E% SMI"
31
32 /*
33 * NAME
34 * xsetenv, xgetenv, Xgetenv - manage an alternate environment space
35 *
36 * SYNOPSIS
37 * int ret = xsetenv(file)
38 * char *x = xgetenv("FOO");
39 * char *x = Xgetenv("FOO");
40 *
41 * DESCRIPTION
42 * xsetenv() reads the given file into an internal buffer
43 * and sets up an alternate environment.
44 *
45 * Return values: 1 - OKAY
46 * 0 - troubles reading the file
47 * -1 - troubles opening the file
48 *
49 * xgetenv() returns the environment value from the
50 * alternate environment.
51 *
52 * Return values: (char *)0 - no value for that variable
53 * pointer - the value
54 *
55 * Xgetenv() returns the environment value from the
56 * alternate environment.
57 *
58 * Return values: "" - no value for that variable
59 * pointer - the value
60 *
61 * LIMITATIONS
62 * Assumes the environment is < 5120 bytes, as in the UNIX
63 * System environment. Assumes < 512 lines in the file.
64 * These values may be adjusted below.
65 */
66
67 #include <sys/types.h>
68 #include "libmail.h"
69 #include <stdio.h>
70 #include <string.h>
71 #include <fcntl.h>
72 #include <ctype.h>
73
74 #include <stdlib.h>
75 #include <unistd.h>
76
77 #define MAXVARS 512
78 #define MAXENV 5120
79
80 static char **xenv = 0;
81 static char *(xenvptrs[MAXVARS]);
82 static char xbuf[MAXENV];
83
84 static void reduce(char *);
85
86 /*
87 * set up an environment buffer
88 * and the pointers into it
89 */
90 int
xsetenv(char * xfile)91 xsetenv(char *xfile)
92 {
93 int envctr, infd;
94 ssize_t i, nread;
95
96 /* Open the file */
97 infd = open(xfile, O_RDONLY);
98 if (infd == -1) {
99 return (-1);
100 }
101
102 /* Read in the entire file. */
103 nread = read(infd, xbuf, sizeof (xbuf));
104 if (nread < 0) {
105 (void) close(infd);
106 return (0);
107 }
108
109 /*
110 * Set up pointers into the buffer.
111 * Replace \n with \0.
112 * Collapse white space around the = sign and at the
113 * beginning and end of the line.
114 */
115 xenv = xenvptrs;
116 xenv[0] = &xbuf[0];
117 for (i = 0, envctr = 0; i < nread; i++) {
118 if (xbuf[i] == '\n') {
119 xbuf[i] = '\0';
120 reduce(xenv[envctr]);
121 xenv[++envctr] = &xbuf[i+1];
122 if (envctr == MAXVARS) {
123 break;
124 }
125 }
126 }
127
128 xenv[envctr] = 0;
129 (void) close(infd);
130 return (1);
131 }
132
133 /*
134 * Let getenv() do the dirty work
135 * of looking up the variable. We
136 * do this by temporarily resetting
137 * environ to point to the local area.
138 */
139 char *
xgetenv(char * env)140 xgetenv(char *env)
141 {
142 extern char **environ;
143 char *ret, **svenviron = environ;
144
145 environ = xenv;
146 ret = getenv(env);
147 environ = svenviron;
148 return (ret);
149 }
150
151 /*
152 * Let xgetenv() do the dirty work
153 * of looking up the variable.
154 */
155 char *
Xgetenv(char * env)156 Xgetenv(char *env)
157 {
158 char *ret = xgetenv(env);
159 return (ret ? ret : "");
160 }
161
162 /*
163 * Remove the spaces within the environment variable.
164 * The variable can look like this:
165 *
166 * <sp1> variable <sp2> = <sp3> value <sp4> \0
167 *
168 * All spaces can be removed, except within
169 * the variable name and the value.
170 */
171
172 static void
reduce(char * from)173 reduce(char *from)
174 {
175 char *to = from;
176 char *svfrom = from;
177
178 /* <sp1> */
179 while (*from &&isspace((int)*from))
180 from++;
181
182 /* variable */
183 while (*from && (*from != '=') && !isspace((int)*from))
184 *to++ = *from++;
185
186 /* <sp2> */
187 while (*from && isspace((int)*from))
188 from++;
189
190 /* = */
191 if (*from == '=')
192 *to++ = *from++;
193
194 /* <sp3> */
195 while (*from && isspace((int)*from))
196 from++;
197
198 /* value */
199 while (*from)
200 *to++ = *from++;
201
202 /* <sp4> */
203 while ((to > svfrom) && isspace((int)to[-1]))
204 to--;
205 *to = '\0';
206 }
207