Libc-262.tar.gz

[apple/libc.git] / stdlib / getenv.c

diff --git a/stdlib/getenv.c b/stdlib/getenv.c
new file mode 100644 (file)
index 0000000..51d9073
--- /dev/null
+++ b/stdlib/getenv.c
@@ -0,0 +1,108 @@
+/*
+ * Copyright (c) 1999 Apple Computer, Inc. All rights reserved.
+ *
+ * @APPLE_LICENSE_HEADER_START@
+ * 
+ * The contents of this file constitute Original Code as defined in and
+ * are subject to the Apple Public Source License Version 1.1 (the
+ * "License").  You may not use this file except in compliance with the
+ * License.  Please obtain a copy of the License at
+ * http://www.apple.com/publicsource and read it before using this file.
+ * 
+ * This Original Code and all software distributed under the License are
+ * distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY KIND, EITHER
+ * EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
+ * INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE OR NON-INFRINGEMENT.  Please see the
+ * License for the specific language governing rights and limitations
+ * under the License.
+ * 
+ * @APPLE_LICENSE_HEADER_END@
+ */
+/*
+ * Copyright (c) 1987, 1993
+ *     The Regents of the University of California.  All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *    notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *    notice, this list of conditions and the following disclaimer in the
+ *    documentation and/or other materials provided with the distribution.
+ * 3. All advertising materials mentioning features or use of this software
+ *    must display the following acknowledgement:
+ *     This product includes software developed by the University of
+ *     California, Berkeley and its contributors.
+ * 4. Neither the name of the University nor the names of its contributors
+ *    may be used to endorse or promote products derived from this software
+ *    without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+
+#include <stdlib.h>
+#include <stddef.h>
+#include <string.h>
+
+#include <crt_externs.h>
+
+char *__findenv __P((const char *, int *));
+
+/*
+ * getenv --
+ *     Returns ptr to value associated with name, if any, else NULL.
+ */
+char *
+getenv(name)
+       const char *name;
+{
+       int offset;
+
+       return (__findenv(name, &offset));
+}
+
+/*
+ * __findenv --
+ *     Returns pointer to value associated with name, if any, else NULL.
+ *     Sets offset to be the offset of the name/value combination in the
+ *     environmental array, for use by setenv(3) and unsetenv(3).
+ *     Explicitly removes '=' in argument name.
+ *
+ *     This routine *should* be a static; don't use it.
+ */
+char *
+__findenv(name, offset)
+       register const char *name;
+       int *offset;
+{
+       register int len;
+       register const char *np;
+       register char **p, *c;
+
+        char **environ = *_NSGetEnviron();
+
+       if (name == NULL || environ == NULL)
+               return (NULL);
+       for (np = name; *np && *np != '='; ++np)
+               continue;
+       len = np - name;
+       for (p = environ; (c = *p) != NULL; ++p)
+               if (strncmp(c, name, len) == 0 && c[len] == '=') {
+                       *offset = p - environ;
+                       return (c + len + 1);
+               }
+       return (NULL);
+}