diff --git a/autoload.cpp b/autoload.cpp
index de8576323..dd3dafbf3 100644
--- a/autoload.cpp
+++ b/autoload.cpp
@@ -20,11 +20,11 @@ static const int kAutoloadStalenessInterval = 15;
 file_access_attempt_t access_file(const wcstring &path, int mode) {
     file_access_attempt_t result = {0};
     struct stat statbuf;
-    if (wstat(path.c_str(), &statbuf)) {
+    if (wstat(path, &statbuf)) {
         result.error = errno;
     } else {
         result.mod_time = statbuf.st_mtime;
-        if (waccess(path.c_str(), mode)) {
+        if (waccess(path, mode)) {
             result.error = errno;
         } else {
             result.accessible = true;
diff --git a/common.cpp b/common.cpp
index 33bbc8ac2..6a1680e7c 100644
--- a/common.cpp
+++ b/common.cpp
@@ -1781,7 +1781,7 @@ bool string_prefixes_string(const wcstring &proposed_prefix, const wcstring &val
     return prefix_size <= value.size() && value.compare(0, prefix_size, proposed_prefix) == 0;
 }
 
-int create_directory( const wchar_t *d )
+int create_directory( const wcstring &d )
 {
 	int ok = 0;
 	struct stat buf;
@@ -1805,7 +1805,7 @@ int create_directory( const wchar_t *d )
 		if( errno == ENOENT )
 		{
             wcstring dir = wdirname(d);
-			if( !create_directory( dir.c_str() ) )
+			if( !create_directory( dir ) )
 			{
 				if( !wmkdir( d, 0700 ) )
 				{
diff --git a/common.h b/common.h
index cdefd5543..3cd469b99 100644
--- a/common.h
+++ b/common.h
@@ -559,7 +559,7 @@ void tokenize_variable_array( const wcstring &val, wcstring_list_t &out);
 
    \return 0 if, at the time of function return the directory exists, -1 otherwise.
 */
-int create_directory( const wchar_t *d );
+int create_directory( const wcstring &d );
 
 /**
    Print a short message about how to file a bug report to stderr
diff --git a/highlight.cpp b/highlight.cpp
index 059ccbfe1..1f34cd4cd 100644
--- a/highlight.cpp
+++ b/highlight.cpp
@@ -128,7 +128,7 @@ static bool is_potential_path( const wcstring &cpath )
         must_be_dir = cleaned_path[cleaned_path.length()-1] == L'/';
         if( must_be_dir )
         {
-            dir = wopendir( cleaned_path.c_str() );
+            dir = wopendir( cleaned_path );
             res = !!dir;
             if( dir )
             {
@@ -144,12 +144,12 @@ static bool is_potential_path( const wcstring &cpath )
             {
                 res = true;
             }
-            else if( (dir = wopendir( dir_name.c_str() )) )
+            else if( (dir = wopendir( dir_name)) )
             {
                 wcstring ent;
                 while (wreaddir(dir, ent))
                 {
-                    if( wcsncmp( ent.c_str(), base_name.c_str(), base_name.length() ) == 0 )
+                    if( ent == base_name )
                     {
                         res = true;
                         break;
@@ -802,7 +802,7 @@ static void tokenize( const wchar_t * const buff, int * const color, const int p
 					if( slash_idx != wcstring::npos )
 					{
 						dir.resize(slash_idx);
-						if( wstat( dir.c_str(), &buff ) == -1 )
+						if( wstat( dir, &buff ) == -1 )
 						{
 							color[ tok_get_pos( &tok ) ] = HIGHLIGHT_ERROR;
 							if( error )
diff --git a/history.cpp b/history.cpp
index ad9abca27..b31d76941 100644
--- a/history.cpp
+++ b/history.cpp
@@ -409,7 +409,7 @@ void history_t::load_old_if_needed(void)
 	
 	if( ! filename.empty() )
 	{
-		if( ( fd = wopen( filename.c_str(), O_RDONLY ) ) > 0 )
+		if( ( fd = wopen( filename, O_RDONLY ) ) > 0 )
 		{
 			off_t len = lseek( fd, 0, SEEK_END );
 			if( len != (off_t)-1)
@@ -595,7 +595,7 @@ void history_t::save_internal()
 	if( ! tmp_name.empty() )
 	{
         FILE *out;
-		if( (out=wfopen( tmp_name.c_str(), "w" ) ) )
+		if( (out=wfopen( tmp_name, "w" ) ) )
 		{
                 
             /* Load old */
@@ -639,7 +639,7 @@ void history_t::save_internal()
 			else
 			{
                 wcstring new_name = history_filename(name, wcstring());
-				wrename(tmp_name.c_str(), new_name.c_str());
+				wrename(tmp_name, new_name);
 			}
 		}
 	}	
@@ -664,7 +664,7 @@ void history_t::clear(void) {
     old_item_offsets.clear();
     wcstring filename = history_filename(name, L"");
     if (! filename.empty())
-        wunlink(filename.c_str());
+        wunlink(filename);
     this->clear_file_state();
     
 }
@@ -710,7 +710,7 @@ int file_detection_context_t::perform_file_detection(bool test_all) {
             if (path.at(0) != '/') {
                 path.insert(0, working_directory);
             }
-            path_is_valid = (0 == waccess(path.c_str(), F_OK));
+            path_is_valid = (0 == waccess(path, F_OK));
         }
         
         
diff --git a/path.cpp b/path.cpp
index 8a2d26e1e..b866d6ef1 100644
--- a/path.cpp
+++ b/path.cpp
@@ -81,10 +81,10 @@ bool path_get_path_string(const wcstring &cmd_str, wcstring &output, const env_v
             if (path_len == 0) continue;
             
             append_path_component(new_cmd, cmd_str);
-			if( waccess( new_cmd.c_str(), X_OK )==0 )
+			if( waccess( new_cmd, X_OK )==0 )
 			{
 				struct stat buff;
-				if( wstat( new_cmd.c_str(), &buff )==-1 )
+				if( wstat( new_cmd, &buff )==-1 )
 				{
 					if( errno != EACCES )
 					{
diff --git a/wildcard.cpp b/wildcard.cpp
index 01bfbc4b2..49b61a9af 100644
--- a/wildcard.cpp
+++ b/wildcard.cpp
@@ -593,7 +593,7 @@ static void wildcard_completion_allocate( std::vector<completion_t> &list,
 	  non-symlinks by first doing an lstat, and if the file is not a
 	  link we copy the results over to the regular stat buffer.
 	*/
-	if( ( lstat_res = lwstat( fullname.c_str(), &lbuf ) ) )
+	if( ( lstat_res = lwstat( fullname, &lbuf ) ) )
 	{
 		sz=-1;
 		stat_res = lstat_res;
@@ -603,7 +603,7 @@ static void wildcard_completion_allocate( std::vector<completion_t> &list,
 		if( S_ISLNK(lbuf.st_mode))
 		{
 			
-			if( ( stat_res = wstat( fullname.c_str(), &buf ) ) )
+			if( ( stat_res = wstat( fullname, &buf ) ) )
 			{
 				sz=-1;
 			}
@@ -863,7 +863,7 @@ static int wildcard_expand_internal( const wchar_t *wc,
 							  will be added in the next pass.
 							*/
 							struct stat buf;
-							if( !wstat( long_name.c_str(), &buf ) )
+							if( !wstat( long_name, &buf ) )
 							{
 								skip = S_ISDIR(buf.st_mode);
 							}							
diff --git a/wutil.cpp b/wutil.cpp
index c3dd80fc0..07fe9f1dc 100644
--- a/wutil.cpp
+++ b/wutil.cpp
@@ -118,25 +118,25 @@ wchar_t *wgetcwd( wchar_t *buff, size_t sz )
 	return ret;
 }
 
-int wchdir( const wchar_t * dir )
+int wchdir( const wcstring &dir )
 {
     cstring tmp = wcs2string(dir);
 	return chdir( tmp.c_str() );
 }
 
-FILE *wfopen(const wchar_t *path, const char *mode)
+FILE *wfopen(const wcstring &path, const char *mode)
 {
 	cstring tmp = wcs2string(path);
 	return fopen(tmp.c_str(), mode);
 }
 
-FILE *wfreopen(const wchar_t *path, const char *mode, FILE *stream)
+FILE *wfreopen(const wcstring &path, const char *mode, FILE *stream)
 {
     cstring tmp = wcs2string(path);
     return freopen(tmp.c_str(), mode, stream);
 }
 
-int wopen(const wchar_t *pathname, int flags, ...)
+int wopen(const wcstring &pathname, int flags, ...)
 {
     cstring tmp = wcs2string(pathname);
 	int res=-1;
@@ -154,25 +154,25 @@ int wopen(const wchar_t *pathname, int flags, ...)
     return res;
 }
 
-int wcreat(const wchar_t *pathname, mode_t mode)
+int wcreat(const wcstring &pathname, mode_t mode)
 {
     cstring tmp = wcs2string(pathname);
     return creat(tmp.c_str(), mode);
 }
 
-DIR *wopendir(const wchar_t *name)
+DIR *wopendir(const wcstring &name)
 {
     cstring tmp = wcs2string(name);
     return opendir(tmp.c_str());
 }
 
-int wstat(const wchar_t *file_name, struct stat *buf)
+int wstat(const wcstring &file_name, struct stat *buf)
 {
     cstring tmp = wcs2string(file_name);
     return stat(tmp.c_str(), buf);
 }
 
-int lwstat(const wchar_t *file_name, struct stat *buf)
+int lwstat(const wcstring &file_name, struct stat *buf)
 {
    // fprintf(stderr, "%s\n", __PRETTY_FUNCTION__);
     cstring tmp = wcs2string(file_name);
@@ -180,31 +180,31 @@ int lwstat(const wchar_t *file_name, struct stat *buf)
 }
 
 
-int waccess(const wchar_t *file_name, int mode)
+int waccess(const wcstring &file_name, int mode)
 {
     cstring tmp = wcs2string(file_name);
     return access(tmp.c_str(), mode);
 }
 
-int wunlink(const wchar_t *file_name)
+int wunlink(const wcstring &file_name)
 {
     cstring tmp = wcs2string(file_name);
     return unlink(tmp.c_str());
 }
 
-void wperror(const wchar_t *s)
+void wperror(const wcstring &s)
 {
 	int e = errno;
-	if( s != 0 )
+	if( !s.empty() )
 	{
-		fwprintf( stderr, L"%ls: ", s );
+		fwprintf( stderr, L"%ls: ", s.c_str() );
 	}
 	fwprintf( stderr, L"%s\n", strerror( e ) );
 }
 
 #ifdef HAVE_REALPATH_NULL
 
-wchar_t *wrealpath(const wchar_t *pathname, wchar_t *resolved_path)
+wchar_t *wrealpath(const wcstring &pathname, wchar_t *resolved_path)
 {
 	cstring tmp = wcs2string(pathname);
 	char *narrow_res = realpath( tmp.c_str(), 0 );	
@@ -346,7 +346,7 @@ wcstring wgettext2(const wcstring &in) {
     return result;
 }
 
-const wchar_t *wgetenv( const wchar_t *name )
+const wchar_t *wgetenv( const wcstring &name )
 {
     ASSERT_IS_MAIN_THREAD();
     cstring name_narrow = wcs2string(name);
@@ -361,13 +361,13 @@ const wchar_t *wgetenv( const wchar_t *name )
 	
 }
 
-int wmkdir( const wchar_t *name, int mode )
+int wmkdir( const wcstring &name, int mode )
 {
 	cstring name_narrow = wcs2string(name);
 	return mkdir( name_narrow.c_str(), mode );
 }
 
-int wrename( const wchar_t *old, const wchar_t *newv )
+int wrename( const wcstring &old, const wcstring &newv )
 {
     cstring old_narrow = wcs2string(old);
 	cstring new_narrow =wcs2string(newv);
diff --git a/wutil.h b/wutil.h
index d3e241d65..5d81662ad 100644
--- a/wutil.h
+++ b/wutil.h
@@ -44,53 +44,53 @@ void wutil_destroy();
 /**
    Wide character version of fopen().
 */
-FILE *wfopen(const wchar_t *path, const char *mode);
+FILE *wfopen(const wcstring &path, const char *mode);
 
 /**
    Wide character version of freopen().
 */
-FILE *wfreopen(const wchar_t *path, const char *mode, FILE *stream);
+FILE *wfreopen(const wcstring &path, const char *mode, FILE *stream);
 
 /**
    Wide character version of open().
 */
-int wopen(const wchar_t *pathname, int flags, ...);
+int wopen(const wcstring &pathname, int flags, ...);
 
 /**
    Wide character version of creat().
 */
-int wcreat(const wchar_t *pathname, mode_t mode);
+int wcreat(const wcstring &pathname, mode_t mode);
 
 
 /**
    Wide character version of opendir().
 */
-DIR *wopendir(const wchar_t *name);
+DIR *wopendir(const wcstring &name);
 
 /**
    Wide character version of stat().
 */
-int wstat(const wchar_t *file_name, struct stat *buf);
+int wstat(const wcstring &file_name, struct stat *buf);
 
 /**
    Wide character version of lstat().
 */
-int lwstat(const wchar_t *file_name, struct stat *buf);
+int lwstat(const wcstring &file_name, struct stat *buf);
 
 /**
    Wide character version of access().
 */
-int waccess(const wchar_t *pathname, int mode);
+int waccess(const wcstring &pathname, int mode);
 
 /**
    Wide character version of unlink().
 */
-int wunlink(const wchar_t *pathname);
+int wunlink(const wcstring &pathname);
 
 /**
    Wide character version of perror().
 */
-void wperror(const wchar_t *s);
+void wperror(const wcstring &s);
 
 /**
    Wide character version of getcwd().
@@ -100,7 +100,7 @@ wchar_t *wgetcwd( wchar_t *buff, size_t sz );
 /**
    Wide character version of chdir()
 */
-int wchdir( const wchar_t * dir );
+int wchdir( const wcstring &dir );
 
 /** 
 	Wide character version of realpath function. Just like the GNU
@@ -108,7 +108,7 @@ int wchdir( const wchar_t * dir );
 	second argument, in which case the result will be allocated using
 	malloc, and must be free'd by the user.
 */
-wchar_t *wrealpath(const wchar_t *pathname, wchar_t *resolved_path);
+wchar_t *wrealpath(const wcstring &pathname, wchar_t *resolved_path);
 
 /**
    Wide character version of readdir()
@@ -139,16 +139,16 @@ wcstring wgettext2(const wcstring &in);
 /**
    Wide character version of getenv
 */
-const wchar_t *wgetenv( const wchar_t *name );
+const wchar_t *wgetenv( const wcstring &name );
 
 /**
    Wide character version of mkdir
 */
-int wmkdir( const wchar_t *dir, int mode );
+int wmkdir( const wcstring &dir, int mode );
 
 /**
    Wide character version of rename
 */
-int wrename( const wchar_t *oldName, const wchar_t *newName );
+int wrename( const wcstring &oldName, const wcstring &newName );
 
 #endif