1 files changed, 147 insertions, 0 deletions
diff --git a/src/lib/libast/misc/setenviron.c b/src/lib/libast/misc/setenviron.c
new file mode 100644
index 0000000..c67477e
--- /dev/null
+++ b/src/lib/libast/misc/setenviron.c
@@ -0,0 +1,147 @@
+/***********************************************************************
+*                                                                      *
+*               This software is part of the ast package               *
+*          Copyright (c) 1985-2011 AT&T Intellectual Property          *
+*                      and is licensed under the                       *
+*                 Eclipse Public License, Version 1.0                  *
+*                    by AT&T Intellectual Property                     *
+*                                                                      *
+*                A copy of the License is available at                 *
+*          http://www.eclipse.org/org/documents/epl-v10.html           *
+*         (with md5 checksum b35adb5213ca9657e911e9befb180842)         *
+*                                                                      *
+*              Information and Software Systems Research               *
+*                            AT&T Research                             *
+*                           Florham Park NJ                            *
+*                                                                      *
+*                 Glenn Fowler <gsf@research.att.com>                  *
+*                  David Korn <dgk@research.att.com>                   *
+*                   Phong Vo <kpv@research.att.com>                    *
+*                                                                      *
+***********************************************************************/
+#pragma prototyped
+
+#include "intercepts.h"
+
+#include <fs3d.h>
+
+/*
+ * put name=value in the environment
+ * pointer to value returned
+ * environ==0 is ok
+ *
+ *	setenviron("N=V")	add N=V
+ *	setenviron("N")		delete N
+ *	setenviron(0)		expect more (pre-fork optimization)
+ *
+ * _ always placed at the top
+ */
+
+#define INCREMENT	16		/* environ increment		*/
+
+char*
+setenviron(const char* akey)
+{
+#undef	setenviron
+	static char**	envv;		/* recorded environ		*/
+	static char**	next;		/* next free slot		*/
+	static char**	last;		/* last free slot (0)		*/
+	static char	ok[] = "";	/* delete/optimization ok return*/
+
+	char*		key = (char*)akey;
+	register char**	v = environ;
+	register char**	p = envv;
+	register char*	s;
+	register char*	t;
+	int		n;
+
+	ast.env_serial++;
+	if (intercepts.intercept_setenviron)
+		return (*intercepts.intercept_setenviron)(akey);
+	if (p && !v)
+	{
+		environ = next = p;
+		*++next = 0;
+	}
+	else if (p != v || !v)
+	{
+		if (v)
+		{
+			while (*v++);
+			n = v - environ + INCREMENT;
+			v = environ;
+		}
+		else
+			n = INCREMENT;
+		if (!p || (last - p + 1) < n)
+		{
+			if (!p && fs3d(FS3D_TEST))
+			{
+				/*
+				 * kick 3d initialization
+				 */
+
+				close(open(".", O_RDONLY));
+				v = environ;
+			}
+			if (!(p = newof(p, char*, n, 0)))
+				return 0;
+			last = p + n - 1;
+		}
+		envv = environ = p;
+		if (v && v[0] && v[0][0] == '_' && v[0][1] == '=')
+			*p++ = *v++;
+		else
+			*p++ = "_=";
+		if (!v)
+			*p = 0;
+		else
+			while (*p = *v++)
+				if (p[0][0] == '_' && p[0][1] == '=')
+					envv[0] = *p;
+				else
+					p++;
+		next = p;
+		p = envv;
+	}
+	else if (next == last)
+	{
+		n = last - v + INCREMENT + 1;
+		if (!(p = newof(p, char*, n, 0)))
+			return 0;
+		last = p + n - 1;
+		next = last - INCREMENT;
+		envv = environ = p;
+	}
+	if (!key)
+		return ok;
+	for (; s = *p; p++)
+	{
+		t = key;
+		do
+		{
+			if (!*t || *t == '=')
+			{
+				if (*s == '=')
+				{
+					if (!*t)
+					{
+						v = p++;
+						while (*v++ = *p++);
+						next--;
+						return ok;
+					}
+					*p = key;
+					return (s = strchr(key, '=')) ? s + 1 : (char*)0;
+				}
+				break;
+			}
+		} while (*t++ == *s++);
+	}
+	if (!(s = strchr(key, '=')))
+		return ok;
+	p = next;
+	*++next = 0;
+	*p = key;
+	return s + 1;
+}