CRE Programmer's Guide

CRE Services
Common Run-Time Environment (CRE) Programmer’s Guide—528146-004
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Standard Log
Standard Log
Standard log is a special file that is available to all programs that use the CRE. If you
open standard log explicitly, you must open it for write-only access. Your program does
not have to declare it or specify its attributes although it can do so. The CRE and run-
time libraries write messages to standard log such as error messages, warnings, and
informational messages. A user program can also send messages to standard log by
calling CRE_Log_Message_. See CRE_Log_Message_
on page 6-25.
A FORTRAN program cannot open standard log using a default unit number, as it can
standard input (UNIT 5) and standard output (UNIT 6). A FORTRAN program can,
however, use the FORTRAN routines PAUSE or STOP to write a message to standard
log. The
FORTRAN Reference Manual describes the PAUSE and STOP statements.
The device for standard log must support sequential write access. The CRE supports
the following devices for standard log:
•
A process (including a spooler collector)
•
The operator console
•
A disk file
•
A terminal
•
A printer
By default, the CRE writes log messages to your process’s home terminal. You can
direct log messages to another file, however, by specifying a file name in a TACL
ASSIGN command or PARAM command.
•
If an ASSIGN specifies the logical name STDERR, the CRE uses the physical
name from the ASSIGN as the name of standard log.
•
If a PARAM specifies EXECUTION-LOG, the CRE uses the value of the
EXECUTION-LOG PARAM as the name of standard log. If the EXECUTION-LOG
PARAM specifies an asterisk (*), the CRE does not open a file for standard log and
discards messages that your program writes to standard log.
•
If an ASSIGN specifies STDERR and a PARAM specifies EXECUTION-LOG, the
CRE uses the physical name from the ASSIGN unless the physical name specifies
your home terminal, in which case the CRE uses the value of the
EXECUTION-LOG PARAM or, if the EXECUTION-LOG PARAM value is an
asterisk, the CRE does not open standard log.
The CRE does not open a file for standard log if the ASSIGN for STDERR specifies
either:
•
Blanks for the file name
•
The process’s home terminal, and the value of the EXECUTION-LOG PARAM is
an asterisk
Although the CRE might not open a file for standard log, it accepts requests to open
standard log and requests to write to standard log, but the CRE discards the data you
write and indicates a successful write.