1 files changed, 83 insertions, 0 deletions
diff --git a/libbb/setup_environment.c b/libbb/setup_environment.c
new file mode 100644
index 000000000..874a58efa
--- /dev/null
+++ b/libbb/setup_environment.c
@@ -0,0 +1,83 @@
+/* vi: set sw=4 ts=4: */
+/*
+ * Copyright 1989 - 1991, Julianne Frances Haugh <jockgrrl@austin.rr.com>
+ * 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 Julianne F. Haugh 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 JULIE HAUGH 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 JULIE HAUGH 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 <stdio.h>
+#include <errno.h>
+#include <unistd.h>
+#include <string.h>
+#include <stdlib.h>
+#include <syslog.h>
+#include <ctype.h>
+#include "libbb.h"
+
+
+
+#define DEFAULT_LOGIN_PATH      "/bin:/usr/bin"
+#define DEFAULT_ROOT_LOGIN_PATH "/usr/sbin:/bin:/usr/bin:/sbin"
+
+void setup_environment(const char *shell, int loginshell, int changeenv, const struct passwd *pw)
+{
+	if (loginshell) {
+		const char *term;
+
+		/* Change the current working directory to be the home directory
+		 * of the user.  It is a fatal error for this process to be unable
+		 * to change to that directory.  There is no "default" home
+		 * directory.
+		 * Some systems default to HOME=/
+		 */
+		if (chdir(pw->pw_dir)) {
+			xchdir("/");
+			fputs("warning: cannot change to home directory\n", stderr);
+		}
+
+		/* Leave TERM unchanged.  Set HOME, SHELL, USER, LOGNAME, PATH.
+		   Unset all other environment variables.  */
+		term = getenv("TERM");
+		clearenv();
+		if (term)
+			xsetenv("TERM", term);
+		xsetenv("HOME",    pw->pw_dir);
+		xsetenv("SHELL",   shell);
+		xsetenv("USER",    pw->pw_name);
+		xsetenv("LOGNAME", pw->pw_name);
+		xsetenv("PATH",   (pw->pw_uid ? DEFAULT_LOGIN_PATH : DEFAULT_ROOT_LOGIN_PATH));
+	}
+	else if (changeenv) {
+		/* Set HOME, SHELL, and if not becoming a super-user,
+		   USER and LOGNAME.  */
+		xsetenv("HOME",  pw->pw_dir);
+		xsetenv("SHELL", shell);
+		if (pw->pw_uid) {
+			xsetenv("USER",    pw->pw_name);
+			xsetenv("LOGNAME", pw->pw_name);
+		}
+	}
+}