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.