1 | /* |
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2 | FUNCTION |
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3 | <<getenv>>---look up environment variable |
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4 | |
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5 | INDEX |
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6 | getenv |
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7 | INDEX |
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8 | environ |
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9 | |
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10 | SYNOPSIS |
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11 | #include <stdlib.h> |
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12 | char *getenv(const char *<[name]>); |
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13 | |
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14 | DESCRIPTION |
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15 | <<getenv>> searches the list of environment variable names and values |
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16 | (using the global pointer ``<<char **environ>>'') for a variable whose |
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17 | name matches the string at <[name]>. If a variable name matches, |
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18 | <<getenv>> returns a pointer to the associated value. |
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19 | |
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20 | RETURNS |
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21 | A pointer to the (string) value of the environment variable, or |
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22 | <<NULL>> if there is no such environment variable. |
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23 | |
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24 | PORTABILITY |
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25 | <<getenv>> is ANSI, but the rules for properly forming names of environment |
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26 | variables vary from one system to another. |
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27 | |
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28 | <<getenv>> requires a global pointer <<environ>>. |
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29 | */ |
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30 | |
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31 | /* |
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32 | * Copyright (c) 1987, 2000 Regents of the University of California. |
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33 | * All rights reserved. |
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34 | * |
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35 | * Redistribution and use in source and binary forms are permitted |
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36 | * provided that: (1) source distributions retain this entire copyright |
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37 | * notice and comment, and (2) distributions including binaries display |
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38 | * the following acknowledgement: ``This product includes software |
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39 | * developed by the University of California, Berkeley and its contributors'' |
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40 | * in the documentation or other materials provided with the distribution |
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41 | * and in all advertising materials mentioning features or use of this |
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42 | * software. Neither the name of the University nor the names of its |
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43 | * contributors may be used to endorse or promote products derived |
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44 | * from this software without specific prior written permission. |
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45 | * THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR |
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46 | * IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED |
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47 | * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. |
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48 | */ |
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49 | |
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50 | #ifndef _REENT_ONLY |
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51 | |
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52 | #include <stdlib.h> |
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53 | #include <stddef.h> |
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54 | #include <string.h> |
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55 | |
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56 | /* |
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57 | * _findenv -- |
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58 | * Returns pointer to value associated with name, if any, else NULL. |
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59 | * Sets offset to be the offset of the name/value combination in the |
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60 | * environmental array, for use by setenv(3) and unsetenv(3). |
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61 | * Explicitly removes '=' in argument name. |
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62 | * |
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63 | * This routine *should* be a static; don't use it. |
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64 | */ |
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65 | |
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66 | char * |
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67 | _findenv (register const char *name, |
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68 | int *offset) |
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69 | { |
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70 | return _findenv_r (_REENT, name, offset); |
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71 | } |
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72 | |
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73 | /* |
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74 | * getenv -- |
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75 | * Returns ptr to value associated with name, if any, else NULL. |
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76 | */ |
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77 | |
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78 | char * |
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79 | getenv (const char *name) |
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80 | { |
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81 | int offset; |
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82 | |
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83 | return _findenv_r (_REENT, name, &offset); |
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84 | } |
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85 | |
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86 | #endif /* !_REENT_ONLY */ |
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