Index: bindings.doc
==================================================================
--- bindings.doc
+++ bindings.doc
@@ -118,10 +118,14 @@
 
 '^u' <location>
   Add an object with the current MRU values to that location, even if
   there is already another object of the same class at that location.
 
+'ex' <command>
+  Export a level (given the operating system command to receive the
+  exported data). See export.doc for details.
+
 'lc' <number>
   Set the level code number. This is a 16-bit number which can be used in
   the class codes of your puzzle set for whatever purpose you wish; the
   game engine does not use this value itself.
 

Index: default.heromeshrc
==================================================================
--- default.heromeshrc
+++ default.heromeshrc
@@ -145,10 +145,11 @@
 ?.editKey.ctrl.P: ^P
 ?.editKey.ctrl.Q: ^Q
 ?.editKey.ctrl.S: ^S
 ?.editKey.space: ^c
 ?.editKey.return: ^e
+?.editKey.f2: select 'ex',:Export_Level;
 ?.editClick.left: ^a
 ?.editClick.alt.left: ^u
 ?.editClick.right: delete from objects where x=$X and y=$Y and up is null;
 
 ! Global key bindings

Index: edit.c
==================================================================
--- edit.c
+++ edit.c
@@ -692,10 +692,78 @@
   objects[n]->misc1=m->misc1;
   objects[n]->misc2=m->misc2;
   objects[n]->misc3=m->misc3;
   pflink(n);
 }
+
+static void fprint_esc(FILE*fp,Uint8 c,const char*t) {
+  char isimg=0;
+  if(!c) return;
+  fputc(c,fp);
+  while(*t) switch(c=*t++) {
+    case 1 ... 8: fprintf(fp,"\\%c",c+'0'-1); break;
+    case 10: fprintf(fp,"\\n"); break;
+    case 11: fprintf(fp,"\\l"); break;
+    case 12: fprintf(fp,"\\c"); break;
+    case 14: fprintf(fp,"\\i"); isimg=1; break;
+    case 15: fprintf(fp,"\\b"); break;
+    case 16: fprintf(fp,"\\q"); break;
+    case 31:
+      if(!*t) break;
+      fprintf(fp,"\\x%02X",*t++);
+      break;
+    case 32 ... 127:
+      if(c=='\\') {
+        if(isimg) isimg=0; else fputc(c,fp);
+      }
+      fputc(c,fp);
+      break;
+    default:
+      fprintf(fp,"\\x%02X",c);
+  }
+  fputc('\n',fp);
+}
+
+static void fprint_misc(FILE*fp,Value v) {
+  switch(v.t) {
+    case TY_NUMBER: fprintf(fp," %u",(int)v.u); break;
+    case TY_CLASS: fprintf(fp," $%s",classes[v.u]->name); break;
+    case TY_MESSAGE: fprintf(fp," %s%s",v.u<256?"":"#",v.u<256?standard_message_names[v.u]:messages[v.u-256]);
+    case TY_LEVELSTRING: fprintf(fp," %%%u",(int)v.u); break;
+    default: fprintf(fp," ???"); break;
+  }
+}
+
+static void export_level(const char*cmd) {
+  int i;
+  Uint32 n;
+  Object*o;
+  FILE*fp;
+  if(!cmd) return;
+  fp=popen(cmd,"w");
+  if(!fp) {
+    screen_message("Cannot open pipe");
+    return;
+  }
+  fprintf(fp,"; Free Hero Mesh exported level ID=%d ORD=%d\n",level_id,level_ord);
+  fprint_esc(fp,'@',level_title);
+  fprintf(fp,"C %d\nD %d %d\n",level_code,pfwidth,pfheight);
+  for(i=0;i<64*64;i++) {
+    n=playfield[i];
+    while(n!=VOIDLINK) {
+      o=objects[n];
+      fprintf(fp,"%d %d $%s %d",o->x,o->y,classes[o->class]->name,o->image);
+      fprint_misc(fp,o->misc1);
+      fprint_misc(fp,o->misc2);
+      fprint_misc(fp,o->misc3);
+      fprintf(fp," %d\n",o->dir);
+      n=o->up;
+    }
+  }
+  for(i=0;i<nlevelstrings;i++) fprint_esc(fp,'%',levelstrings[i]);
+  pclose(fp);
+}
 
 static int editor_command(int prev,int cmd,int number,int argc,sqlite3_stmt*args,void*aux) {
   int x,y;
   switch(cmd) {
     case '^a': // Add object (no duplicates)
@@ -717,10 +785,14 @@
     case '^Q': // Quit
       return -1;
     case '^S': // Save level
       save_level();
       return 1;
+    case 'ex': // Export level
+      if(argc<2) return prev;
+      export_level(sqlite3_column_text(args,1));
+      return prev;
     case 'go': // Select level
       load_level(number);
       return 1;
     case 'lc': // Set level code
       level_code=number;

ADDED   export.doc
Index: export.doc
==================================================================
--- export.doc
+++ export.doc
@@ -0,0 +1,60 @@
+This document describes the level export format of Free Hero Mesh.
+
+You can use this format for the following purposes:
+
+* To copy a level in Free Hero Mesh, within the same puzzle set or from
+one puzzle set to another one.
+
+* To export a level, to be parsed by an external program.
+
+* To produce by an external program and then import into Free Hero Mesh.
+
+* To edit it in a text editor.
+
+Each line is one record, and is terminated by a line feed. Everything in
+this file is case-sensitive.
+
+
+=== Types of records ===
+
+;comment
+  A comment. A blank line is also a comment.
+
+@title
+  Specify the title of the level. This may contain escapes. A line break
+  must be escaped, and a backslash must be escaped, although a quotation
+  mark does not need to be escaped.
+
+C code
+  The level code number, from 0 to 65535.
+
+D width height
+  The play field dimensions. The width and height must be 1 to 64. This
+  line must come before any objects are listed, and is mandatory.
+
+x y $class image misc1 misc2 misc3 dir
+  Specify an object. Objects are listed starting from the top left corner,
+  going right, and within each cell the objects are listed from bottom to
+  top. Coordinates are one-based. The image is a number (0 for the first
+  image), misc1 to misc3 are misc values (see below), and dir is also a
+  number (0 for east, up to 7 for southeast).
+
+%string
+  A level string. The level strings are numbered in order, starting from
+  string 0. The format is like that of the title.
+
+
+=== Misc values ===
+
+A number is written in decimal, and must be 0 to 65535.
+
+A class name has $ at first.
+
+A message name will start with # if it is a user-defined message, or will
+have no prefix if it is a standard message.
+
+A reference to a level string starts with % and is then the number.
+
+Nine of the misc values are written with spaces inside the value, although
+there are spaces around the value.
+