The operation results
in an error that you can trap using the ErrorLevel statement when the file doesn??™t exist. When the
ErrorLevel value matches the value you provide, then the If statement executes the command. In
this case, because the code uses the Not clause, the reverse is true, the If statement only executes
the Goto command when the error level is not 1. Notice that, in this case, the code uses the Echo
CREATING BATCH FILES 145
command to display an error message to the user??”Echo works not only for turning messages on
or off, but for displaying custom messages to the user that the Echo setting doesn??™t hide as well.
Once the code performs these initial steps, it determines whether the MyFile.TXT file does exist
using the Exit clause of the If statement. When the file exists, the code immediately begins processing
it. Otherwise, the code displays a message prompting the user to type information for such
a file. Notice the Pause command, which pauses the batch file execution until the user presses a key.
The Copy command sends whatever the user types at the console (CON) to the MyFile.TXT file until
it detects an end of file character, which the user creates by pressing Ctrl+Z.
Pages:
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391