--- frontend/file-selector.cc
+++ frontend/file-selector.cc
@@ -35,6 +35,7 @@
 #include <cstdio>
 #include <cstdlib>
 #include <cstring>
+#include <string>
 #include <unistd.h>
 
 #include "pisa_aleart_dialog.h"
@@ -1023,17 +1024,14 @@
   // check write access to the directory (note that we need execute
   // privileges as well)
 
-  char *slash = strrchr( file, '/');
-  *slash = '\0';		// temporarily truncate to dirname
-  const char *dir = (file == slash
-		     ? "/"	// whoops!, file in root directory
-		     : file);
+  const char *slash = strrchr( file, '/');
+  std::string dir( file, slash - file);
+  if (dir.empty())
+    dir = "/";
 
   bool w_ok = false;		// assume the worst
-  if (0 == access( dir, F_OK ))
-    w_ok = (0 == access( dir, W_OK | X_OK ));
-
-  *slash = '/';			// restore filename
+  if (0 == access( dir.c_str(), F_OK ))
+    w_ok = (0 == access( dir.c_str(), W_OK | X_OK ));
 
   return w_ok;
 }
--- frontend/pisa_view_manager.cc
+++ frontend/pisa_view_manager.cc
@@ -45,6 +45,7 @@
 #include <sys/stat.h>
 #include <dirent.h>
 #include <locale.h>
+#include <string>
 
 /*------------------------------------------------------------*/
 #include "pisa_view_manager.h"
@@ -1170,10 +1171,10 @@
 pisa_file_type
 view_manager::get_file_type (const char *filename)
 {
-  char *dot   = strrchr (filename, '.');
+  const char *dot   = strrchr (filename, '.');
   if (!dot)
     {
-      char *slash = strrchr (filename, '/');
+      const char *slash = strrchr (filename, '/');
       if (   (strlen (slash) == strlen ("/" PACKAGE_TARNAME "XXXXXX"))
 	  && (0 == strncmp (slash, "/" PACKAGE_TARNAME,
 			    strlen ("/" PACKAGE_TARNAME))))
@@ -1260,19 +1261,19 @@
 {
   int cancel = 0;		// default: don't cancel
 
-  char *slash = strrchr( regexp, '/' );
+  const char *slash = strrchr( regexp, '/' );
 
   if (!slash)
     return cancel = 1;
 
-  *slash = '\0';		// regexp now holds the directory name
-  char dirname[ strlen( regexp )];
-  strcpy( dirname, regexp );
+  std::string s( regexp, slash - regexp);
+  char dirname[ s.size()];
+  strcpy( dirname, s.c_str());
 
-  *slash = '^';			// re-anchor the regexp
+  s = std::string("^") + (slash + 1); // re-anchor the regexp
 
   regex_t *comp_regex = new regex_t;
-  int comp = regcomp( comp_regex, slash, REG_EXTENDED );
+  int comp = regcomp( comp_regex, s.c_str(), REG_EXTENDED );
 
   if (0 == comp)
     {
--- lib/imgstream.cc
+++ lib/imgstream.cc
@@ -185,7 +185,7 @@
   return lt_dlclose (lib);
 }
 
-static int reversionsort (const void*, const void*);
+static int reversionsort (const dirent**, const dirent**);
 int selector (const dirent *);
 				// forward declarations
 
@@ -321,7 +321,7 @@
 //! The C library's versionsort() function in reverse.
 static
 int
-reversionsort (const void *a, const void *b)
+reversionsort (const dirent **a, const dirent **b)
 {
   return versionsort (b, a);
 }