System information

Most of the commands reference a particular file or group of files. The form of a file reference is
specified in Section 1.2.2.
1.2.2 File References
A file reference identifies a particular file or group of files on a particular disk attached to CP/M.
These file references are either unambiguous (ufn) or ambiguous (afn). An unambiguous file
reference uniquely identifies a single file, while an ambiguous file reference is satisfied by a
number of different files.
File references consist of two parts: the primary filename and the filetype. Although the filetype
is optional, it usually is generic. For example, the filetype ASM is used to denote that the file is
an assembly language source file, while the primary filename distinguishes each particular source
file. The two names are separated by a period, as shown in the following example:
filename.typ
In this example, filename is the primary filename of eight characters or less, and typ is the
filetype of no more than three characters. As mentioned above, the name
filename
is also allowed and is equivalent to a filetype consisting of three blanks. The characters used in
specifying an unambiguous file reference cannot contain any of the following special characters:
< > . , ; : = ? * [ ] % | ( ) / \
while all alphanumerics and remaining special characters are allowed.
An ambiguous file reference is used for directory search and pattern matching. The form of an
ambiguous file reference is similar to an unambiguous reference, except the symbol ? can be
interspersed throughout the primary and secondary names. In various commands throughout
CP/M, the ? symbol matches any character of a filename in the ? position. Thus, the ambiguous
reference
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1.1 Introduction CP/M Operating System Manual
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