Operating environment of application programs started by OpenTP1

The standard input (stdin), standard output (stdout), and standard error output (stderr) of SUPs, SPPs, and MHPs are redirected by OpenTP1.
Input from an operator is not accepted even when the operator uses the COBOL STOP instruction. The DISPLAY instruction is available. However, the output data might be mixed with data output from another UAP if the DISPLAY instruction is used.
When a UAP is activated, a directory $DCDIR/tmp/home/user-server-name.XX (where XX is a sequence number) is created. The UAP runs with this directory as the current working directory.
You can change this directory by setting the prc_current_work_path operand in the system common definition.
The user ID (UID) and group ID (GID) have the values specified at environment setup for the user server.
The root directory remains as a forward slash (/).
The following file descriptors are open during UAP execution:
File descriptor 0: Standard input file descriptor
File descriptor 1: Standard output file descriptor
File descriptor 2: Standard error output file descriptor
umask is 000.
No control terminal is used.

When creating a UAP process, OpenTP1 sets a UAP signal for the process automatically. Table 1-7 lists UAP signals which are set by OpenTP1.

Table 1-7 UAP signals set by OpenTP1

Signal name	Setting at the time of UAP process creation	Operation
SIGHUP	SIG_DFL (default)	exit
SIGINT	SIG_IGN (ignored)	ignore
SIGQUIT	SIG_DFL (default)	core
SIGILL	SIG_DFL (default)	core
SIGTRAP	SIG_IGN (ignored)	ignore
SIGIOT^#	SIG_DFL (default)	core
SIGABRT^#	SIG_DFL (default)	core
SIGEMT	SIG_DFL (default)	core
SIGFEP	SIG_DFL (default)	core
SIGKILL	--	exit
SIGBUS	SIG_DFL (default)	core
SIGSEGV	SIG_DFL (default)	core
SIGSYS	SIG_DFL (default)	core
SIGPIPE^#	SIG_IGN (ignored)	ignore
SIGALRM	SIG_IGN (ignored)	ignore
SIGTERM	SIG_DFL (default)	exit
SIGUSR1	SIG_IGN (ignored)	ignore
SIGUSR2	SIG_IGN (ignored)	ignore
SIGCLD	SIG_DFL (default)	ignore

Note: When specifying signal operations using UAP, do not stop the process by invoking exit() or abort() within the specified signal handler. When the process is stopped in the signal handler, the OpenTP1 system will shut down even if the signal interruption occurs during critical OpenTP1 processing. Furthermore, do not overwrite the value of the external variable errno in the signal handler.; #: These signals cannot be reset. When creating a UAP, do not reset the operation of the signal within the program.