1 | /* |
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2 | * Copyright (c) 1987 Regents of the University of California. |
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3 | * All rights reserved. |
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4 | * |
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5 | * Redistribution and use in source and binary forms, with or without |
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6 | * modification, are permitted provided that the following conditions |
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7 | * are met: |
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8 | * 1. Redistributions of source code must retain the above copyright |
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9 | * notice, this list of conditions and the following disclaimer. |
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10 | * 2. Redistributions in binary form must reproduce the above copyright |
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11 | * notice, this list of conditions and the following disclaimer in the |
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12 | * documentation and/or other materials provided with the distribution. |
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13 | * 3. All advertising materials mentioning features or use of this software |
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14 | * must display the following acknowledgement: |
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15 | * This product includes software developed by the University of |
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16 | * California, Berkeley and its contributors. |
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17 | * 4. Neither the name of the University nor the names of its contributors |
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18 | * may be used to endorse or promote products derived from this software |
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19 | * without specific prior written permission. |
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20 | * |
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21 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND |
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22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
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23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
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24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE |
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25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
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26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
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27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
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28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
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29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
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30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
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31 | * SUCH DAMAGE. |
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32 | */ |
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33 | |
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34 | #if defined(LIBC_SCCS) && !defined(lint) |
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35 | static char sccsid[] = "@(#)setenv.c 5.6 (Berkeley) 6/4/91"; |
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36 | #endif /* LIBC_SCCS and not lint */ |
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37 | |
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38 | #include <stddef.h> |
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39 | #include <stdlib.h> |
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40 | #include <string.h> |
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41 | |
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42 | char *_findenv(); |
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43 | |
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44 | /* |
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45 | * setenv -- |
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46 | * Set the value of the environmental variable "name" to be |
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47 | * "value". If rewrite is set, replace any current value. |
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48 | */ |
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49 | setenv(name, value, rewrite) |
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50 | register const char *name; |
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51 | register const char *value; |
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52 | int rewrite; |
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53 | { |
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54 | extern char **environ; |
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55 | static int alloced; /* if allocated space before */ |
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56 | register char *C; |
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57 | int l_value, offset; |
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58 | |
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59 | if (*value == '=') /* no `=' in value */ |
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60 | ++value; |
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61 | l_value = strlen(value); |
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62 | if ((C = _findenv(name, &offset))) { /* find if already exists */ |
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63 | if (!rewrite) |
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64 | return (0); |
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65 | if (strlen(C) >= l_value) { /* old larger; copy over */ |
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66 | while (*C++ = *value++); |
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67 | return (0); |
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68 | } |
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69 | } else { /* create new slot */ |
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70 | register int cnt; |
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71 | register char **P; |
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72 | |
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73 | for (P = environ, cnt = 0; *P; ++P, ++cnt); |
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74 | if (alloced) { /* just increase size */ |
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75 | environ = (char **)realloc((char *)environ, |
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76 | (size_t)(sizeof(char *) * (cnt + 2))); |
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77 | if (!environ) |
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78 | return (-1); |
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79 | } |
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80 | else { /* get new space */ |
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81 | alloced = 1; /* copy old entries into it */ |
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82 | P = (char **)malloc((size_t)(sizeof(char *) * |
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83 | (cnt + 2))); |
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84 | if (!P) |
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85 | return (-1); |
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86 | memcpy(P, environ, cnt * sizeof(char *)); |
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87 | environ = P; |
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88 | } |
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89 | environ[cnt + 1] = NULL; |
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90 | offset = cnt; |
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91 | } |
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92 | for (C = (char *)name; *C && *C != '='; ++C); /* no `=' in name */ |
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93 | if (!(environ[offset] = /* name + `=' + value */ |
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94 | malloc((size_t)((int)(C - name) + l_value + 2)))) |
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95 | return (-1); |
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96 | for (C = environ[offset]; (*C = *name++) && *C != '='; ++C) |
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97 | ; |
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98 | for (*C++ = '='; *C++ = *value++; ) |
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99 | ; |
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100 | return (0); |
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101 | } |
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102 | |
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103 | /* |
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104 | * unsetenv(name) -- |
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105 | * Delete environmental variable "name". |
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106 | */ |
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107 | void |
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108 | unsetenv(name) |
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109 | const char *name; |
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110 | { |
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111 | extern char **environ; |
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112 | register char **P; |
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113 | int offset; |
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114 | |
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115 | while (_findenv(name, &offset)) /* if set multiple times */ |
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116 | for (P = &environ[offset];; ++P) |
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117 | if (!(*P = *(P + 1))) |
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118 | break; |
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119 | } |
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