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scoutos / prex-0.9.0 / usr / lib / libc / stdlib / getenv.c @ 03e9c04a

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/*
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 * Copyright (c) 1987, 1993
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 *        The Regents of the University of California.  All rights reserved.
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 *
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 * Redistribution and use in source and binary forms, with or without
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 * modification, are permitted provided that the following conditions
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 * are met:
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 * 1. Redistributions of source code must retain the above copyright
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 *    notice, this list of conditions and the following disclaimer.
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 * 2. Redistributions in binary form must reproduce the above copyright
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 *    notice, this list of conditions and the following disclaimer in the
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 *    documentation and/or other materials provided with the distribution.
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 * 3. Neither the name of the University nor the names of its contributors
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 *    may be used to endorse or promote products derived from this software
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 *    without specific prior written permission.
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 *
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 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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 * SUCH DAMAGE.
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 */
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#include <stdlib.h>
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#include <stddef.h>
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#include <string.h>
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extern char **environ;
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char *__findenv(const char *, int *);
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/*
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 * getenv --
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 *        Returns ptr to value associated with name, if any, else NULL.
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 */
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char *
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getenv(name)
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        const char *name;
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{
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        int offset;
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        return (__findenv(name, &offset));
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}
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/*
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 * __findenv --
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 *        Returns pointer to value associated with name, if any, else NULL.
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 *        Sets offset to be the offset of the name/value combination in the
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 *        environmental array, for use by setenv(3) and unsetenv(3).
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 *        Explicitly removes '=' in argument name.
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 *
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 *        This routine *should* be a static; don't use it.
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 */
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char *
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__findenv(name, offset)
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        const char *name;
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        int *offset;
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{
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        size_t len;
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        const char *np;
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        char **p, *c;
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        if (name == NULL || environ == NULL)
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                return (NULL);
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        for (np = name; *np && *np != '='; ++np)
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                continue;
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        len = np - name;
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        for (p = environ; (c = *p) != NULL; ++p)
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                if (strncmp(c, name, len) == 0 && c[len] == '=') {
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                        *offset = p - environ;
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                        return (c + len + 1);
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                }
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        return (NULL);
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}