Executes an operating system file append command from
within ABL.
Syntax
OS-APPEND
{ source-filename | VALUE ( expression ) }
{ target-filename | VALUE ( expression ) }
|
-
source-filename
- The name of the source file. (If you append file A to file B,
file A is the source file.) If you specify a directory, OS-APPEND
generates an error. The filename can contain Unicode characters.
See OpenEdge Development: Internationalizing Applications for
more information about Unicode.
- VALUE ( expression )
- An expression that returns the name of the source file. (If
you append file A to file B, file A is the source file.) expression can
contain constants, field names, and variable names. The filename
can contain Unicode characters.
-
target-filename
- The name of the target file. (If you append file A to file B,
file B is the target file.) The filename can contain Unicode characters.
- VALUE ( expression )
- An expression that returns the name of the target file. (If
you append file A to file B, file B is the target file.) expression can
contain constants, field names, and variable names. The filename
can contain Unicode characters.
Example
This
procedure opens a dialog box that prompts the user to choose a source file
for the append. It then prompts for a name for the target file.
Finally, the procedure uses the OS-APPEND statement to append the
source file to the target file.
r-os-app.p
DEFINE VARIABLE sourcefile AS CHARACTER NO-UNDO.
DEFINE VARIABLE targetfile AS CHARACTER NO-UNDO FORMAT "x(20)"
VIEW-AS FILL-IN.
DEFINE VARIABLE OKpressed AS LOGICAL NO-UNDO INITIAL TRUE.
Main:
REPEAT:
SYSTEM-DIALOG GET-FILE sourcefile
TITLE "Choose Source File For Append"
MUST-EXIST
USE-FILENAME
UPDATE OKpressed.
IF OKpressed = FALSE THEN
LEAVE Main.
UPDATE targetfile WITH FRAME appendframe.
OS-APPEND VALUE(sourcefile) VALUE(targetfile).
END.
|
Notes
- The
filenames must conform to the naming conventions of the underlying
operating system.
- If target-file names a file that does not
exist or a directory, OS-APPEND becomes an OS-COPY and a copy is
created in the current or specified directory. If an error occurs
during the copy, the AVM deletes the partial target-file.
- Although an error can occur during execution of this statement,
the statement does not generate an error message, raise an error
condition, or affect the program's flow in any way. Check for an
execution error by using the OS-ERROR function and evaluating the
return.
- If you specify the same file for the source and the target,
the append fails but OS-ERROR is not set.