Changeset 51

Timestamp:

Apr 19, 2021, 11:33:50 PM (4 years ago)

Author:

Alex Taylor

Message:

Clarify limitations of DOSExecPGM wrapper

File:

• rxutilex/trunk/rxutilex.txt (modified) (3 diffs)

rxutilex/trunk/rxutilex.txt

@@ -169 +169 @@
 
 -------------------------------------------------------------------------
-Sys2Exec                                                                 
-                                                                         
+Sys2Exec
+
 Executes an external program and returns the process ID or termination
-code.  Wrapper to DosExecPgm().  Note that text mode programs requiring 
-user input cannot be started from a PM program using this function; 
-they can only be started from another text mode program (in which case 
-it is inadvisable to start them using any mode other than EXEC_SYNC).
-                                                                         
-REXX ARGUMENTS:                                                          
+code.  Wrapper to DosExecPgm.  Note that there are limitations on the type
+of program which can be started, depending on the calling program's type.
+In particular, text mode (VIO) programs which expect input must not be
+started from a graphical (PM) program.  If it is necessary to start a VIO
+program from a PM program using this function, it should be run detached
+('D' mode).
+
+VIO programs requiring input can be started from other VIO programs, but it
+generally advisable to use start them in wait ('W') mode.
+
+
+REXX ARGUMENTS:
   1. Name of executable program to run.                        (REQUIRED)
   2. Argument string to pass to the called program.
@@ -184 +190 @@
       'N' or 'A': Run the program in no-wait (asynchronous) mode (EXEC_ASYNC).
       'D' or 'B': Run the program detached (EXEC_BACKGROUND).
-                                                                         
-REXX RETURN VALUE:                                                       
+
+REXX RETURN VALUE:
   If EXEC_SYNC mode was requested, returns the termination status (this is
   _not_ the same as the return code) from the started program.  Otherwise,
@@ -690 +696 @@
 Sys2SetSize
 
-Set the size of a file to a specific number of bytes; files larger than 
+Set the size of a file to a specific number of bytes; files larger than
 2GB are supported (this function is a wrapper to DosSetFileSizeL).