1 /* $OpenBSD: setenv.c,v 1.9 2005/08/08 08:05:37 espie Exp $ */ 2 /* 3 * Copyright (c) 1987 Regents of the University of California. 4 * All rights reserved. 5 * 6 * Redistribution and use in source and binary forms, with or without 7 * modification, are permitted provided that the following conditions 8 * are met: 9 * 1. Redistributions of source code must retain the above copyright 10 * notice, this list of conditions and the following disclaimer. 11 * 2. Redistributions in binary form must reproduce the above copyright 12 * notice, this list of conditions and the following disclaimer in the 13 * documentation and/or other materials provided with the distribution. 14 * 3. Neither the name of the University nor the names of its contributors 15 * may be used to endorse or promote products derived from this software 16 * without specific prior written permission. 17 * 18 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND 19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 21 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE 22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 28 * SUCH DAMAGE. 29 */ 30 31 /* OPENBSD ORIGINAL: lib/libc/stdlib/setenv.c */ 32 33 #include "includes.h" 34 #if !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV) 35 36 #include <stdlib.h> 37 #include <string.h> 38 39 extern char **environ; 40 41 /* OpenSSH Portable: __findenv is from getenv.c rev 1.8, made static */ 42 /* 43 * __findenv -- 44 * Returns pointer to value associated with name, if any, else NULL. 45 * Sets offset to be the offset of the name/value combination in the 46 * environmental array, for use by setenv(3) and unsetenv(3). 47 * Explicitly removes '=' in argument name. 48 */ 49 static char * 50 __findenv(const char *name, size_t *offset) 51 { 52 extern char **environ; 53 int len, i; 54 const char *np; 55 char **p, *cp; 56 57 if (name == NULL || environ == NULL) 58 return (NULL); 59 for (np = name; *np && *np != '='; ++np) 60 ; 61 len = np - name; 62 for (p = environ; (cp = *p) != NULL; ++p) { 63 for (np = name, i = len; i && *cp; i--) 64 if (*cp++ != *np++) 65 break; 66 if (i == 0 && *cp++ == '=') { 67 *offset = p - environ; 68 return (cp); 69 } 70 } 71 return (NULL); 72 } 73 74 #ifndef HAVE_SETENV 75 /* 76 * setenv -- 77 * Set the value of the environmental variable "name" to be 78 * "value". If rewrite is set, replace any current value. 79 */ 80 int 81 setenv(const char *name, const char *value, int rewrite) 82 { 83 static char **lastenv; /* last value of environ */ 84 char *C; 85 size_t l_value, offset; 86 87 if (*value == '=') /* no `=' in value */ 88 ++value; 89 l_value = strlen(value); 90 if ((C = __findenv(name, &offset))) { /* find if already exists */ 91 if (!rewrite) 92 return (0); 93 if (strlen(C) >= l_value) { /* old larger; copy over */ 94 while ((*C++ = *value++)) 95 ; 96 return (0); 97 } 98 } else { /* create new slot */ 99 size_t cnt; 100 char **P; 101 102 for (P = environ; *P != NULL; P++) 103 ; 104 cnt = P - environ; 105 P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2)); 106 if (!P) 107 return (-1); 108 if (lastenv != environ) 109 memcpy(P, environ, cnt * sizeof(char *)); 110 lastenv = environ = P; 111 offset = cnt; 112 environ[cnt + 1] = NULL; 113 } 114 for (C = (char *)name; *C && *C != '='; ++C) 115 ; /* no `=' in name */ 116 if (!(environ[offset] = /* name + `=' + value */ 117 malloc((size_t)((int)(C - name) + l_value + 2)))) 118 return (-1); 119 for (C = environ[offset]; (*C = *name++) && *C != '='; ++C) 120 ; 121 for (*C++ = '='; (*C++ = *value++); ) 122 ; 123 return (0); 124 } 125 #endif /* HAVE_SETENV */ 126 127 #ifndef HAVE_UNSETENV 128 /* 129 * unsetenv(name) -- 130 * Delete environmental variable "name". 131 */ 132 void 133 unsetenv(const char *name) 134 { 135 char **P; 136 size_t offset; 137 138 while (__findenv(name, &offset)) /* if set multiple times */ 139 for (P = &environ[offset];; ++P) 140 if (!(*P = *(P + 1))) 141 break; 142 } 143 #endif /* HAVE_UNSETENV */ 144 145 #endif /* !defined(HAVE_SETENV) || !defined(HAVE_UNSETENV) */ 146