sync code with last improvements from OpenBSD

app/xedit/lisp/setenv.c

@@ -0,0 +1,178 @@
+/*	$OpenBSD: setenv.c,v 1.1 2013/01/14 22:05:52 matthieu Exp $ */
+/*
+ * Copyright (c) 1987 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. 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 <errno.h>
+#include <stdlib.h>
+#include <string.h>
+
+char *__findenv(const char *name, int len, int *offset);
+
+extern char **environ;
+static char **lastenv;				/* last value of environ */
+
+/*
+ * putenv --
+ *	Add a name=value string directly to the environmental, replacing
+ *	any current value.
+ */
+int
+putenv(char *str)
+{
+	char **P, *cp;
+	size_t cnt;
+	int offset = 0;
+
+	for (cp = str; *cp && *cp != '='; ++cp)
+		;
+	if (*cp != '=') {
+		errno = EINVAL;
+		return (-1);			/* missing `=' in string */
+	}
+
+	if (__findenv(str, (int)(cp - str), &offset) != NULL) {
+		environ[offset++] = str;
+		/* could be set multiple times */
+		while (__findenv(str, (int)(cp - str), &offset)) {
+			for (P = &environ[offset];; ++P)
+				if (!(*P = *(P + 1)))
+					break;
+		}
+		return (0);
+	}
+
+	/* create new slot for string */
+	for (P = environ; *P != NULL; P++)
+		;
+	cnt = P - environ;
+	P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
+	if (!P)
+		return (-1);
+	if (lastenv != environ)
+		memcpy(P, environ, cnt * sizeof(char *));
+	lastenv = environ = P;
+	environ[cnt] = str;
+	environ[cnt + 1] = NULL;
+	return (0);
+}
+
+/*
+ * setenv --
+ *	Set the value of the environmental variable "name" to be
+ *	"value".  If rewrite is set, replace any current value.
+ */
+int
+setenv(const char *name, const char *value, int rewrite)
+{
+	char *C, **P;
+	const char *np;
+	int l_value, offset = 0;
+
+	for (np = name; *np && *np != '='; ++np)
+		;
+#ifdef notyet
+	if (*np) {
+		errno = EINVAL;
+		return (-1);			/* has `=' in name */
+	}
+#endif
+
+	l_value = strlen(value);
+	if ((C = __findenv(name, (int)(np - name), &offset)) != NULL) {
+		int tmpoff = offset + 1;
+		if (!rewrite)
+			return (0);
+#if 0 /* XXX - existing entry may not be writable */
+		if (strlen(C) >= l_value) {	/* old larger; copy over */
+			while ((*C++ = *value++))
+				;
+			return (0);
+		}
+#endif
+		/* could be set multiple times */
+		while (__findenv(name, (int)(np - name), &tmpoff)) {
+			for (P = &environ[tmpoff];; ++P)
+				if (!(*P = *(P + 1)))
+					break;
+		}
+	} else {					/* create new slot */
+		size_t cnt;
+
+		for (P = environ; *P != NULL; P++)
+			;
+		cnt = P - environ;
+		P = (char **)realloc(lastenv, sizeof(char *) * (cnt + 2));
+		if (!P)
+			return (-1);
+		if (lastenv != environ)
+			memcpy(P, environ, cnt * sizeof(char *));
+		lastenv = environ = P;
+		offset = cnt;
+		environ[cnt + 1] = NULL;
+	}
+	if (!(environ[offset] =			/* name + `=' + value */
+	    malloc((size_t)((int)(np - name) + l_value + 2))))
+		return (-1);
+	for (C = environ[offset]; (*C = *name++) && *C != '='; ++C)
+		;
+	for (*C++ = '='; (*C++ = *value++); )
+		;
+	return (0);
+}
+
+/*
+ * unsetenv(name) --
+ *	Delete environmental variable "name".
+ */
+int
+unsetenv(const char *name)
+{
+	char **P;
+	const char *np;
+	int offset = 0;
+
+	if (!name || !*name) {
+		errno = EINVAL;
+		return (-1);
+	}
+	for (np = name; *np && *np != '='; ++np)
+		;
+	if (*np) {
+		errno = EINVAL;
+		return (-1);			/* has `=' in name */
+	}
+
+	/* could be set multiple times */
+	while (__findenv(name, (int)(np - name), &offset)) {
+		for (P = &environ[offset];; ++P)
+			if (!(*P = *(P + 1)))
+				break;
+	}
+	return (0);
+}