diff --git a/src/library.cpp b/src/library.cpp
index 2a7bbf07b3..94f8dfa7a3 100644
--- a/src/library.cpp
+++ b/src/library.cpp
@@ -445,26 +445,14 @@ is passed to :cpp:func:`lammps_commands_string` for processing.
 void lammps_commands_list(void *handle, int ncmd, const char **cmds)
 {
   LAMMPS *lmp = (LAMMPS *) handle;
-
-  int n = ncmd+1;
-  for (int i = 0; i < ncmd; i++) n += strlen(cmds[i]);
-
-  char *str = (char *) lmp->memory->smalloc(n,"lib/commands/list:str");
-  str[0] = '\0';
-  n = 0;
+  std::string allcmds;
 
   for (int i = 0; i < ncmd; i++) {
-    strcpy(&str[n],cmds[i]);
-    n += strlen(cmds[i]);
-    if (str[n-1] != '\n') {
-      str[n] = '\n';
-      str[n+1] = '\0';
-      n++;
-    }
+    allcmds.append(cmds[i]);
+    if (allcmds.back() != '\n') allcmds.append(1,'\n');
   }
 
-  lammps_commands_string(handle,str);
-  lmp->memory->sfree(str);
+  lammps_commands_string(handle,allcmds.c_str());
 }
 
 /* ---------------------------------------------------------------------- */