scoutos / prex-0.9.0 / usr / lib / libc / stdlib / getenv.c @ 03e9c04a
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1 | 03e9c04a | Brad Neuman | /*
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2 | * Copyright (c) 1987, 1993
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3 | * The Regents of the University of California. 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. Neither the name of the University nor the names of its contributors
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14 | * may be used to endorse or promote products derived from this software
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15 | * without specific prior written permission.
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16 | *
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17 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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18 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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19 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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20 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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21 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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22 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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23 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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24 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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25 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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26 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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27 | * SUCH DAMAGE.
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28 | */
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29 | |||
30 | #include <stdlib.h> |
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31 | #include <stddef.h> |
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32 | #include <string.h> |
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33 | |||
34 | extern char **environ; |
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35 | |||
36 | char *__findenv(const char *, int *); |
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37 | |||
38 | /*
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39 | * getenv --
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40 | * Returns ptr to value associated with name, if any, else NULL.
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41 | */
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42 | char *
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43 | getenv(name) |
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44 | const char *name; |
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45 | { |
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46 | int offset;
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47 | |||
48 | return (__findenv(name, &offset));
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49 | } |
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50 | |||
51 | /*
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52 | * __findenv --
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53 | * Returns pointer to value associated with name, if any, else NULL.
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54 | * Sets offset to be the offset of the name/value combination in the
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55 | * environmental array, for use by setenv(3) and unsetenv(3).
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56 | * Explicitly removes '=' in argument name.
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57 | *
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58 | * This routine *should* be a static; don't use it.
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59 | */
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60 | char *
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61 | __findenv(name, offset) |
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62 | const char *name; |
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63 | int *offset;
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64 | { |
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65 | size_t len; |
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66 | const char *np; |
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67 | char **p, *c;
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68 | |||
69 | if (name == NULL || environ == NULL) |
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70 | return (NULL); |
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71 | for (np = name; *np && *np != '='; ++np) |
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72 | continue;
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73 | len = np - name; |
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74 | for (p = environ; (c = *p) != NULL; ++p) |
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75 | if (strncmp(c, name, len) == 0 && c[len] == '=') { |
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76 | *offset = p - environ; |
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77 | return (c + len + 1); |
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78 | } |
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79 | return (NULL); |
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80 | } |