Page of GC20-1819-2 As Updated April 1, 1981 by TNt GN25-0826 This command affects output that is being displayed: • As a response to a CMS command, including prompting messages, error
messages, or normal display responses (as from the TYPE command) • From a proqram • In responsp. to an &TYPE or &BEGTYPE request in an EXEC Once display has been suppressed, and before the command, EXEC completes execution, you can request that display be
signaling another interruption and entering:
program, or
resumed by rt In an EXEC file, if you want to halt or resume display, you must use
the &SrACK control statement to enter the RT or HT commands. For
example, the command issues a message when a disk is accessed:
D
(1 98) RIO If you are qoing to issue the ACCESS command within an EXEC and you do
not wish this message displayed, you could enter the lines: H'r ACCESS 198 D
Note that does not suppress error messages that have the suffixes W, E, S, or- T. Once you have stacked an HT command, all displaving
the remainder of the EXEC file's execution, unless
command is processed, either following an attention described above) or within the EXEC. To execute
command in an EXEC, use the statement: f,STACK R'r is suppressed for
the RT Immediate
interruption (as
the RT Immediate
A physical read to the terminal, for example the result of an &READ control statement, also resets the display setting to RT. !hg You can test the current value of the
display controllinq an EXEC with the &TYPEFLAG special variable. The value of can onlv be one of the literal values HT or RT. For
examole:
&IF EQROTYPE &STACK HT &IF &TYPEFLAG EO HT &SKIP 3 f,TYPE &TYPE &'rVPE &CONTINUE In this example, if NOTYPE is entered as an argument when the EXEC is
invoked, an command is stacked, so that no displaying is done at the
terminal. Within the EXEC, the variable &TYPEFLAG is tested, and, if it
is RT, then a series of gTYPE statements is skipped. Since EXEC does
not have to process these lines, vou can save time and system resources
by not processing 288 User's Guide

Reading from the Console Stack When you are in the CMS environment executing programs or CMS commands,
you can stack commands, either by entering multiple command lines
separated by the logical line end symbol, as follows:
print myfile listingtcp query printer
or by signaling an attention interruption and entering a command line,
as follows:
print myfile listing
cp query printer
In both of the preceding examples, the second command line is saved
in a terminal input buffer, called the console stack. Whenever a read
occurs in your virtual machine, CMS reads lines from the console stack,
if there are any lines in it. If there are no lines in the stack, the
read results in a physical read to your terminal (on a typewriter
terminal, the keyboard unlocks). A virtual machine read occurs whenever a command or subcommand
finishes execution, or yhen an EXEC or a program issues a read request. Many CMS commands also issue read requests, for example, SORT and COPYFILE. If you want to execute one of these commands in an EXEC, you may want to stack, in the console stack, the response to the read
request so that when it is issued it is immediately satisfied. For
exaiiple: &STACK 42-121 i COPYFILE &NAME LISTING A = ASSEMBLE = (SPECS When the COPYFILE command is issued with the SPECS option, a prompting
message for a specification list is issued, followed by a read request.
In this EXEC, the request is satisfied with the line stacked with the &STACK control statement. If the response was not stacked, you would
have to enter the appropriate information from the terminal during the
execution of the EXEC that contained this COPYFILE command line.
In addition to stacking predefined responses to commands and
programs, you can use the console stack to stack CMS commands and EDIT
subcommands, as well as data lines to be read within the EXEC. The number of lines that you can place in the console stack at any
one time varies according to the amount of storage available in your
virtual machine for stacking. You may want to stack one or two lines at
a time, or you may wish to stack many lines. There are several features
available in EXEC that can help you manipulate the stack.
Just as the &TYPE control statement has an &BEGTYPE counterpart, the &STACK control statement has an &BEGSTACK counterpart. You can stack
multiple data lines following an &BEGSTACK statement. Lines stacked in
this way are not scanned by the EXEC processor, and no substitution is
performed on variable symbols. For example, the lines: Section 14. Building EXEC Procedures 289