User`s guide

All command keywords that do not identify built-in commands identify either a
transient program file or a submit file. If the CCP identifies a command keyword as
a transient program, the transient program file is loaded into the TPA from disk and
executed. If it recognizes a submit file, the CCP reconstructs the command line into
the following form:
SUBMIT <command> <command tail>
and attempts to load and execute the SUBMIT utility. Thus, the original command
fie'ld becomes the first command tail field of the SUBMIT command. Section 1.6.5
describes the execution of CP/M 3's SUBMIT utility. The procedure the CCP follows
o parse a standard command line and execute built-in and transient commands is
described as follows:
1. The CCP parses the command line to pick up the command field.
2. If the command field is not preceded by a drive specification, or followed by
a filetype or password field, the CCP checks to see if the command is a CCP
built-in function. If the command is a built-in command, and the CCP can
support the options specified in the command tail, the CCP executes the
command. Otherwise, the CCP goes on to step 3.
3. At this point the CCP assumes the command field references a command file
or submit file on disk. If the optional filetype field is omitted from the com-
mand, the CCP usually assumes the command field references a file of type
COM. For example, if the command field is PIP, the CCP attempts to open
the file PIP.COM.
Optionally, the CP/M 3 utility SETDEF can specify that a filetype of SUB
also be considered when the command filetype field is omitted. When this
automatic submit option is in effect, the CCP attempts to open the command
with a filetype of COM. If the COM file cannot be found, the CCP repeats
the open op eration with a filetype of SUB. As an alternative, the order of
open operations can be reversed so that the CCP attempts to open with a
filetype of SUB first. In either case, the file that is found on disk first deter-
mines the filetype field that is ultimately associated with the command.
If the filetype field is present in the command, it must equal COM, SUB or
PRL. A PRL file is a Page Relocatable file used in Digital Research's multi-
user operating system, MP/M. Under CP/M 3, the CCP handles PRL files
exactly like COM files.
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1.6 System Operation CP/M 3 Programmer's Guide