Prex Home / Browse Source - Prex Version: 0.9.0

root/usr/lib/libc/stdlib/getenv.c

DEFINITIONS

1. getenv
2. __findenv

   1 /*
   2  * Copyright (c) 1987, 1993
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 3. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  30 #include <stdlib.h>
  31 #include <stddef.h>
  32 #include <string.h>
  34 extern char **environ;
  36 char *__findenv(const char *, int *);
  38 /*
  39  * getenv --
  40  *      Returns ptr to value associated with name, if any, else NULL.
  41  */
  42 char *
getenv(name)
  44         const char *name;
  45 {
  46         int offset;
  48         return (__findenv(name, &offset));
  49 }
  51 /*
  52  * __findenv --
  53  *      Returns pointer to value associated with name, if any, else NULL.
  54  *      Sets offset to be the offset of the name/value combination in the
  55  *      environmental array, for use by setenv(3) and unsetenv(3).
  56  *      Explicitly removes '=' in argument name.
  57  *
  58  *      This routine *should* be a static; don't use it.
  59  */
  60 char *
__findenv(name, offset)
  62         const char *name;
  63         int *offset;
  64 {
size_t len;
  66         const char *np;
  67         char **p, *c;
  69         if (name == NULL || environ == NULL)
  70                 return (NULL);
  71         for (np = name; *np && *np != '='; ++np)
  72                 continue;
len = np - name;
  74         for (p = environ; (c = *p) != NULL; ++p)
  75                 if (strncmp(c, name, len) == 0 && c[len] == '=') {
  76                         *offset = p - environ;
  77                         return (c + len + 1);
  78                 }
  79         return (NULL);
  80 }