PTrace Reference Manual

Using PTrace
PTrace Reference Manual—526393-001
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Setting the Initial Input Source
Setting the Initial Input Source
PTrace accepts command input from a terminal, a disk file, or an application process.
The initial input source is determined by the form of the RUN command used to initiate
PTrace. The input source can be changed during the PTrace session.
If you run PTrace without any special instructions, it assumes that input is to come
from the input file used by the TACL/SCF process through which it is being run.
Usually, that input file is a terminal.
To specify an initial input source for the PTrace session, use the IN option on the RUN
command. You can specify a terminal (identified by its logical device name), a disk file,
or an application process. For example, the following TACL RUN command initiates
PTrace and directs it to read commands from a disk file called PTRACE.STARTUP
(the system and volume default to the default values currently in use by the TACL/SCF
process through which you entered the RUN command):
4> PTRACE/IN PTRACE.STARTUP/
If you specify an application process as the IN file, the same application process must
be specified as the OUT file. The application process must open its $RECEIVE file
prior to the PTrace OPEN call, and it must read the PTrace prompt character before
sending a command line to PTrace.
Changing the Input Source
To change the input source during a session, use the PTrace OBEY command,
described in Section 3, PTrace Commands. For example, if the following command
appeared in the PTRACE.STARTUP file described above, PTrace would accept its
next command from the disk file called ATP39:
OBEY ATP39
Under certain circumstances (for example, when an error occurs), PTrace may revert
to a previous input source. These circumstances are described in Ending a PTrace
Session on page 2-12.
Setting the Initial Output Destination
PTrace can direct output to a terminal, a disk file, or an application process. The initial
output destination is determined by the form of the RUN command used to initiate
PTrace. The output destination can be changed during the PTrace session.
If you run PTrace without any special instructions, it assumes that output is to be sent
to the output file used by the TACL/SCF process through which it is being run. Usually,
that output file is a terminal.
To specify an initial output destination for the PTrace session, use the OUT option of
the RUN command. You can specify a terminal (identified by its logical device name), a