IF E
Conditionally executes a Proc command based on the presence or absence of an error condition after processing a TCL command.
Syntax
IF {#} E command
or
IF E operator error-id command
Syntax Elements
# tests for the absence of an error message.
operator performs a value comparison. The operators are:
=Equal to.
#Not equal to.
error-id is the item-id of a system message in the ERRMSG file.
command is a valid Proc command.
Operation
IF # E command tests for the absence of a system message.
IF E command tests for the presence of a system message.
IF E operator error-id command tests to see if the item-id of the system message is equal to the specified error-id.
The IF E command tests for error conditions caused by the execution of a TCL command. After a P command, which executes the command in the primary output buffer, system message numbers are stored in the secondary input buffer. The IF E command references the secondary input buffer. Because some commands destroy the contents of the secondary input buffer, performing some operation on the primary input buffer after a P command but before an IF E command might cause the IF E to fail.
Note
System messages and system message numbers might change with different software releases. Therefore, some user-written Procs might have to be modified to reflect these changes.
Example 1
HCOUNT ORDERS WITH STATUS "BO" PH IF E = 401 O...NO BACKORDERED ITEMS
If the result of the COUNT statement shows that there are
no backordered items, system message 401 (NO ITEMS PRESENT) is displayed.
The PH command outputs the contents of the output
buffer and suppresses any terminal output that is generated by the processed
command, which in this case would have been [401] NO ITEMS PRESENT.
Example 2
M
HBASIC BP T
P
IF E # B0 G 10
X
10 HEDIT BP T
P
G B
If the DataBasic program does not compile correctly, reedit the program. Otherwise, return to TCL.
System message B0 is COMPILATION COMPLETED.