Creates a subprocess of the current process. The context of the
subprocess is copied from the current process. You can use the
SPAWN command to leave Mail temporarily, perform other functions
(such as displaying a directory listing or printing a file), and
then return to Mail.
Format
SPAWN [command]
1 – Parameter
command
Specifies the DCL command string that executes in the context
of the created subprocess. When the command completes, the
subprocess terminates and control is returned to the parent
process. If this parameter is not specified, a subprocess is
created that transfers control to DCL command level.
2 – Qualifiers
2.1 /INPUT
/INPUT=file-spec
Specifies an input file containing one or more DCL command
strings to be executed by the spawned subprocess. If you specify
a command string along with an input file, the command string is
processed before the commands in the input file. Once processing
is complete, the subprocess is terminated.
2.2 /LOGICAL_NAMES
/LOGICAL_NAMES
/NOLOGICAL_NAMES
Specifies that the logical names of the parent process are to be
copied to the subprocess. When you do not want the subprocess to
use the logical names of the parent process, enter the qualifier
/NOLOGICAL_NAMES. The default is /LOGICAL_NAMES.
2.3 /OUTPUT
/OUTPUT=file-spec
Identifies the output file to which the results of the SPAWN
operation are written. Whenever you use the /NOWAIT qualifier,
you should also use the /OUTPUT qualifier to specify a new
output destination. Doing so prevents output from being displayed
while you are specifying new commands. If you omit the /OUTPUT
qualifier, output is written by default to the current SYS$OUTPUT
device.
2.4 /PROCESS
/PROCESS=subprocess-name
Specifies the name of the subprocess to be created. The default
name of the subprocess is USERNAME_n. If the subprocess name
contains spaces or special characters, or is case-sensitive, then
the subprocess name must be enclosed in quotation marks.
2.5 /SYMBOLS
/SYMBOLS
/NOSYMBOLS
Determines whether the system passes DCL global and local symbols
to the subprocess. The default is /SYMBOLS.
2.6 /WAIT
/WAIT
/NOWAIT
Controls whether the system waits until the subprocess is
completed before allowing more commands to be specified. The
/NOWAIT qualifier allows you to specify new commands while the
specified subprocess is running. If you specify /NOWAIT, you
should also use the /OUTPUT qualifier to direct the output stream
to a file, rather than displaying it on your terminal. Doing so
prevents your terminal from being used by more than one process
simultaneously.
3 – Examples
1.MAIL> SPAWN SHOW TIME
This example shows how to create a subprocess that executes the
DCL command SHOW TIME while you are using Mail.
2.MAIL> SPAWN /NOLOGICAL_NAMES SET HOST
_Node: MARS
.
.
.
$ LOGOUT
CRAMMER logged out at ...
%REM-S-END, control returned to node _BETA::
MAIL>
This example shows how to use the SPAWN command to create a
subprocess in which you SET HOST to another node. When you want
to leave node MARS and move back to node BETA, enter the DCL
command LOGOUT. The /NOLOGICAL_NAMES qualifier prevents the
logical names of the parent process from being copied to the
subprocess.