--- freem/src/cmd_zedit.c	2025/05/19 01:08:12	1.1
+++ freem/src/cmd_zedit.c	2025/05/19 02:03:31	1.2
@@ -1,7 +1,7 @@
 
 /*
  *
- *   $Id: cmd_zedit.c,v 1.1 2025/05/19 01:08:12 snw Exp $
+ *   $Id: cmd_zedit.c,v 1.2 2025/05/19 02:03:31 snw Exp $
  *    Implementation of the ZEDIT command
  *
  *  
@@ -26,6 +26,9 @@
  *   along with FreeM.  If not, see <https://www.gnu.org/licenses/>.
  *
  *   $Log: cmd_zedit.c,v $
+ *   Revision 1.2  2025/05/19 02:03:31  snw
+ *   Reverse-engineer and document argumented ZPRINT (thanks to D. Wicksell)
+ *
  *   Revision 1.1  2025/05/19 01:08:12  snw
  *   Add ZEDIT command (properly this time)
  *
@@ -50,11 +53,13 @@ MRESULT cmd_zedit(MACTION *ra)
     short free_editor = FALSE;
 
     if (restricted_mode) {
+        /* we never shell out in restricted mode */
         retval = NOSTAND;
         goto done;
     }
 
     if (rou_name[0] == EOL) {
+        /* there was no current routine */
         retval = NOPGM;
         goto done;
     }        
@@ -64,13 +69,18 @@ MRESULT cmd_zedit(MACTION *ra)
         NULLPTRCHK(tgt_editor,"cmd_zedit");
         
         snprintf (tgt_editor, STRLEN - 1, "/usr/bin/vi");
+
+        /* had to allocate the editor path on the heap,
+           so we need to free it later */         
         free_editor = TRUE;
     }
     
     if (*codptr == SP || *codptr == EOL) {
+        /* argumentless ZEDIT edits the current routine */
         stcpy (tgt_routine, rou_name);
     }
     else {
+        /* argumented ZEDIT edits a specified routine */
         expr (NAME);
         
         if (varnam[0] == '^') {
@@ -94,17 +104,20 @@ MRESULT cmd_zedit(MACTION *ra)
     stcnv_m2c (tgt_routine);
     
     if ((rtn_get_path (tgt_routine, pth)) == FALSE) {
+        /* the routine could not be found */
         retval = NOPGM;
         goto done;
     }
     
     snprintf (editor_command, sizeof (editor_command) - 1, "%s %s", tgt_editor, pth);
-    
+
+    /* make the environment friendly to running external programs */
     sig_attach (SIGUSR1, SIG_IGN);
     set_io (UNIX);
 
     system (editor_command);
 
+    /* back into mumps */
     set_io (MUMPS);
     sig_attach (SIGUSR1, &oncld);