DOS/360 and Successors - Job Control

Job Control

In the description that follows the character "␢" represents a single blank.

All DOS job control statements began with "//" in card columns one and two except end-of-job which was "/&␢", end-of-data, "/*␢", and comments, "*␢".

• The JOB statement indicates "the beginning of control information for a job." The format is "//␢JOB␢␢". must be one to eight alphanumeric characters to identify the job. are ignored.

• The EXEC statement identifies a program to be executed as a job step. "All control statements necessary for execution must be processed" before the exec statement is read. The format is "//␢EXEC␢"

• The PAUSE statement "can be used to allow for operator action between job steps." The format is "//␢PAUSE␢". The comment is used to provide a message to the operator.

• The comments statement may be used to display a message to the operator. The format is "*␢".

• The end of data statement marks the end of data in the input stream. The format is "/*␢". Any data on the statement following the blank is ignored.

• The end of job statement marks the end of a job, and may indicate the end of data to be flushed if the job terminates abnormally. The format is "/&␢". Any data on the statement following the blank is ignored.

• The OPTION statement specifies values of system options that apply to this job. The format is "//␢OPTION␢".

• The ASSGN statement "is used to assign a logical I/O unit to a physical device." The format is "//␢ASSGN␢SYSxxx,". SYSxxx indicates a logical unit such as SYS001 or SYSIPT. is either "X'cuu'" to indicate a physical device (channel and unit), "IGN" for ignore, or "UA" for unassigned. specifies either tape mode settings such as density, parity, etc., or "ALT" to indicate an alternate device.

• The RESET statement resets specified I/O unit assignments to their permanent values. The format is "//␢RESET". may be "SYS" to reset all system logical unit assignments, "PROG" to reset all programmer assignments, "ALL" to reset all assignments, or "SYSxxx" to reset the assignment for the logical unit "SYSxxx", for example SYS002.

• The LISTIO statement instructs the system to print a listing of all specified I/O assignments currently in effect. The format is "//␢LISTIO␢". is "SYS" to list all system assignments, "PROG", "F1", or "F2" to list all assignments for the background or specified foreground partition, "ALL", "SYSxxx", "X'cuu'", "UNITS" to list all assigned units, 'UA" to list all unassigned units, or "DOWN" to list all units marked as inoperative.

• The MTC statement issues command to a magnetic tape unit. The format is "//␢MTC␢,SYSxxx". is a function such as "FSF" to forward space one file or "REW" to rewind the tape. is a number that can specify the number of times the operation is to be performed, such as forward space two files.

• The VOL statement provides disk or tape volume label information for standard label checking. The format is "//␢VOL␢SYSxxx,".

• DOS originally provided the TPLAB statement for tape label information and the DLAB and XTENT statements for disk label and extent information. At least as early as 1968 the TPLAB statement had been replaced by TLBL and the DLAB statement by DLBL. These statements used numerous positional parameters and had fairly high information densities.