Added execvpe().

* This closes #12114 again; while not POSIX, it's just a line away.
* Removed exect() from the header -- not sure where this came from.
  but I can't find anything about it on the net.
* Consolidated use of asterisk style in exec.cpp.

headers/posix/unistd.h

@@ -1,5 +1,5 @@
 /*
- * Copyright 2004-2011 Haiku, Inc. All Rights Reserved.
+ * Copyright 2004-2015 Haiku, Inc. All Rights Reserved.
  * Distributed under the terms of the MIT License.
  */
 #ifndef _UNISTD_H_
@@ -207,13 +207,15 @@ extern int		lockf(int fd, int function, off_t size);
 /* process functions */
 extern pid_t	fork(void);
 extern pid_t	vfork(void);
-extern int		execve(const char *path, char * const argv[], char * const envp[]);
+extern int		execve(const char *path, char * const argv[],
+					char *const environment[]);
 extern int		execl(const char *path, const char *arg, ...);
-extern int		execv(const char *path, char *const *argv);
+extern int		execv(const char *path, char *const argv[]);
 extern int		execlp(const char *file, const char *arg, ...);
 extern int		execle(const char *path, const char *arg , ... /*, char **envp */);
-extern int		exect(const char *path, char *const *argv);
+extern int		execvp(const char *file, char *const argv[]);
-extern int		execvp(const char *file, char *const *argv);
+extern int		execvpe(const char *file, char *const argv[],
+					char *const environment[]);
 
 extern void		_exit(int status) __attribute__ ((noreturn));
 

src/system/libroot/posix/unistd/exec.cpp

@@ -1,6 +1,6 @@
 /*
  * Copyright 2008, Ingo Weinhold, [email protected].
- * Copyright 2004-2005, Axel Dörfler, [email protected]. All rights reserved.
+ * Copyright 2004-2015, Axel Dörfler, [email protected].
  * Distributed under the terms of the MIT License.
  */
 
@@ -135,18 +135,25 @@ execve(const char *path, char* const args[], char* const environment[])
 
 
 int
-execv(const char *path, char * const *argv)
+execv(const char* path, char* const argv[])
 {
 	return do_exec(path, argv, environ, false);
 }
 
 
 int
-execvp(const char *file, char* const* argv)
+execvp(const char* file, char* const argv[])
+{
+	return execvpe(file, argv, environ);
+}
+
+
+int
+execvpe(const char* file, char* const argv[], char* const environment[])
 {
 	// let do_exec() handle cases where file is a path (or invalid)
 	if (file == NULL || strchr(file, '/') != NULL)
-		return do_exec(file, argv, environ, true);
+		return do_exec(file, argv, environment, true);
 
 	// file is just a leaf name, so we have to look it up in the path
 
@@ -189,7 +196,7 @@ execvp(const char *file, char* const* argv)
 
 		// if executable, execute it
 		if (access(path, X_OK) == 0)
-			return do_exec(path, argv, environ, true);
+			return do_exec(path, argv, environment, true);
 	}
 
 	__set_errno(B_ENTRY_NOT_FOUND);
@@ -269,11 +276,11 @@ execle(const char *path, const char *arg, ... /*, char **env */)
 	return do_exec(path, (char* const*)args, env, false);
 }
 
+// TODO: remove this again if possible
+extern int exect(const char *path, char *const *argv);
 
 int
 exect(const char* path, char* const* argv)
 {
-	// ToDo: is this any different?
 	return execv(path, argv);
 }
-