implement "labelmap write" command

doc/src/labelmap.rst

@@ -10,8 +10,14 @@ Syntax
 
    labelmap option args
 
-* *option* = *atom* or *bond* or *angle* or *dihedral* or *improper* or *clear*
-* except for the *clear* option, one or more numeric-type/type-label pairs may be appended
+* *option* = *atom* or *bond* or *angle* or *dihedral* or *improper* or *clear* or *write*
+
+  .. parsed-literal::
+
+     *clear* = no args
+     *write* arg = filename
+     *atom* or *bond* or *angle* or *dihedral* or *improper*
+       args = list of one or more numeric-type/type-label pairs
 
 Examples
 """"""""
@@ -22,6 +28,7 @@ Examples
    labelmap bond 1 carbonyl 2 nitrile
    labelmap atom $(label(carbon)) C  # change type label from 'carbon' to 'C'
    labelmap clear
+   labelmap write mymap.include
 
 Description
 """""""""""
@@ -59,6 +66,11 @@ that when type labels are used, that there is a label defined for
 The *clear* option resets the labelmap and thus discards all previous
 settings.
 
+The *write* option takes a filename as argument and writes the current
+label mappings to a file as labelmap commands, so the file can be copied
+into a different LAMMPS input file or read using the :doc:`include
+<include>` command.
+
 ----------
 
 Restrictions

src/label_map.cpp

@@ -123,9 +123,13 @@ void LabelMap::modify_lmap(int narg, char **arg)
     labels = &itypelabel;
     labels_map = &itypelabel_map;
   } else if (tlabel == "clear") {
-    if (narg != 1) error->all(FLERR, "Incorrect number of arguments for labelmap command");
+    if (narg != 1) error->all(FLERR, "Incorrect number of arguments for labelmap clear command");
     reset_type_labels();
     return;
+  } else if (tlabel == "write") {
+    if (narg != 2) error->all(FLERR, "Incorrect number of arguments for labelmap write command");
+    write_map(arg[1]);
+    return;
   } else
     error->all(FLERR, "Unknown labelmap keyword {}", tlabel);
 
@@ -441,3 +445,46 @@ int LabelMap::read_int(FILE *fp)
   MPI_Bcast(&value, 1, MPI_INT, 0, world);
   return value;
 }
+
+/* ----------------------------------------------------------------------
+   write out all current label map values as labelmap commands
+------------------------------------------------------------------------- */
+
+void LabelMap::write_map(const std::string &filename)
+{
+  if (comm->me == 0) {
+    FILE *fp = fopen(filename.c_str(), "w");
+    if (!fp) error->one(FLERR, "Cannot open label map file {}: {}", filename, utils::getsyserror());
+    if (typelabel_map.size() > 0) {
+      fputs("labelmap atom", fp);
+      for (int i = 0; i < natomtypes; ++i)
+        if (!typelabel[i].empty()) fmt::print(fp, " {} \"\"\" {} \"\"\"", i + 1, typelabel[i]);
+      fputc('\n', fp);
+    }
+    if (btypelabel_map.size() > 0) {
+      fputs("labelmap bond", fp);
+      for (int i = 0; i < nbondtypes; ++i)
+        if (!btypelabel[i].empty()) fmt::print(fp, " {} \"\"\" {} \"\"\"", i + 1, btypelabel[i]);
+      fputc('\n', fp);
+    }
+    if (atypelabel_map.size() > 0) {
+      fputs("labelmap angle", fp);
+      for (int i = 0; i < nangletypes; ++i)
+        if (!atypelabel[i].empty()) fmt::print(fp, " {} \"\"\" {} \"\"\"", i + 1, atypelabel[i]);
+      fputc('\n', fp);
+    }
+    if (dtypelabel_map.size() > 0) {
+      fputs("labelmap dihedral", fp);
+      for (int i = 0; i < ndihedraltypes; ++i)
+        if (!dtypelabel[i].empty()) fmt::print(fp, " {} \"\"\" {} \"\"\"", i + 1, dtypelabel[i]);
+      fputc('\n', fp);
+    }
+    if (itypelabel_map.size() > 0) {
+      fputs("labelmap improper", fp);
+      for (int i = 0; i < nimpropertypes; ++i)
+        if (!itypelabel[i].empty()) fmt::print(fp, " {} \"\"\" {} \"\"\"", i + 1, itypelabel[i]);
+      fputc('\n', fp);
+    }
+    fclose(fp);
+  }
+}

src/label_map.h

@@ -69,6 +69,8 @@ class LabelMap : protected Pointers {
   char *read_string(FILE *);
   void write_string(const std::string &, FILE *);
   int read_int(FILE *);
+
+  void write_map(const std::string &);
 };
 
 }    // namespace LAMMPS_NS