CRE Programmer's Guide

CRE Services
Common Run-Time Environment (CRE) Programmer’s Guide—528146-004
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Standard Output
If you start your program from a TACL command line or a TACL macro, the INFILE in
the startup message is the name you specify in the TACL IN parameter or, if you do not
specify an IN parameter, then the name by which TACL knows your terminal.
If a program other than TACL starts your program, INFILE in the startup message
contains whatever file name the other program stores when it creates the startup
message.
Standard Output
Standard output is a special file that is available to all programs that use the CRE. You
must open it for write-only access.
The device for standard output must support sequential write access. The CRE
supports the following devices for standard output:
•
A process (including a spooler collector)
•
An operator console
•
A disk file
•
A terminal
•
A printer
The CRE determines the file name for standard output as follows. If the OUTFILE
name in your program’s startup message is:
•
Not the name of your program’s home terminal, the CRE uses the OUTFILE name
from the startup message for standard output.
•
Blanks, the CRE does not open a system file but accepts open requests, discards
records that you write to standard output, and indicates a successful write each
time your program writes to standard output.
•
The name of your program’s home terminal and you do not specify the
EXECUTION-LOG PARAM, the CRE opens your home terminal if your program
opens standard output.
•
The name of your program’s home terminal and you specify a file name as the
EXECUTION-LOG, the CRE uses the file you specify for the EXECUTION-LOG as
standard output.
For example, if your home terminal is named $TERM and you specify AFILE for
EXECUTION-LOG, the CRE opens AFILE if a routine in your program opens
standard output:
PARAM EXECUTION-LOG AFILE
RUN myprog / OUT $TERM, ..... /
Note that if you specify an EXECUTION-LOG PARAM, the CRE will not write to
your home terminal under any circumstances, even if EXECUTION-LOG specifies
the name of your home terminal.
•
The name of your program’s home terminal and you specify an asterisk for the
EXECUTION-LOG, the CRE does not open a file for standard output. Instead, each