| 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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