M

machine alias --
An abbreviated notation for a collection of remote machines; machine aliases can be used on command lines to simplify the specification of destination machines.

macro --
A collection of instructions or keystrokes that can be invoked using a single name or keystroke combination, used to automate regular and complex tasks.

mail alias --
A single name used to send e-mail to multiple users at once. For example, many users have aliases set up for mailing to the entire company, single departments, or groups of individuals.

mail folder --
A directory in which you can store related mail messages.

Mail Transfer Agent --
A facility that accepts messages generated by an Mail User Agent, determines a route for delivery, edits the message header as required by the destination and delivery program, and calls the appropriate delivery program to deliver the mail.

Mail User Agent --
A program that provides a user interface for mail message processing, including mail composition and reading.

mailbox --
The folder that opens when you start mail. This is the folder into which your new mail is delivered by default.

mailbox window --
The window that displays the messages in your mailbox or other folders. See also mailbox.

mailing list --
A special-case alias. Each mailing list has an ``owner'' who handles list administration and receives any error messages about bounced messages or other problems with list mail. Mailing list addresses are not validated at the time each message is sent; this can save a significant amount of processing time with a large list of recipients.

makefile --
(programming) A makefile is a file that is used with the program make(1) to keep track of the dependencies between modules of a program, so that when one module is changed, dependent ones are brought up to date.

manual page --
These reference pages can be accessed online using the man(1) command or using SCOHelp. A number (sometimes with letters) in parentheses following a command or filename refers to the manual page section where the command or file is documented. For example, the man(1) command is documented in section 1. Manual pages are also called ``man pages'' or ``reference pages.''

mask --
A series of bit settings that ``cover up'' existing settings, only allowing some settings to show through, while masking out others.

maximize --
To enlarge a window so that it fills the entire screen.

maximize button --
A button in the upper right corner of a window frame that maximizes the window. The button contains an image of a square.

megabyte --
One million bytes. Used to describe the amount of information that can be contained on a disk or in RAM.

memory --
1. See core image. 2. Physical memory representing the available space in main memory; programs are either swapped or paged into physical memory for execution. 3. Virtual memory management techniques permitting programs to treat disk storage as an extension of main memory.

menu --
A screen display that lists options that users can select. Each option causes an action to be taken or another menu to be displayed. Menus are usually located at the top of the window frame in a menu bar. See also option.

menu bar --
A bar across the top of a window, under the title bar, that contains the titles of the pull-down menus for that window.

menu item --
A choice on a menu.

message --
(programming) In a stream, one or more blocks of data or information, with associated STREAMS control structures. Messages can be of several defined types, which identify the message contents. Messages are the only means of transferring data and communicating within a stream.

message block --
(programming) A STREAMS message is made up of one or more message blocks. A message block is referenced by a pointer to a mblk_t structure, which in turn points to the data block (dblk_t) structure and the data buffer.

message box --
A dialog box that provides information, gives the current state of work in progress, asks a question, issues a warning, or draws attention to an error.

message list --
The list of messages displayed in the mailbox window.

message list window --
A window in the Mail program that displays the list of mail messages received.

message queue --
(programming) In a stream, a linked list of messages awaiting processing by a module or driver.

message queue identifier --
(programming) A message queue identifier (msqid) is a unique positive integer created by a msgget(2) system call. Each msqid has a message queue and a data structure associated with it.

message window --
The window in which you create draft messages. See also message list.

metacharacter --
A special character that is replaced by matching character strings when interpreted by the shell. Metacharacters, which define the form of a string, and literal characters, which match only themselves, make up regular expressions.

MIB --
Management Information Base. A tree-structured naming convention that is used to access network data via a network management protocol such as SNMP.

MIB module --
a subtree of the MIB.

MIME --
Multipurpose Internet Mail Extensions. A standard for mail exchange that supports graphical, audio, video, and multi-media messages.

minimize --
To store a window as a window icon, temporarily removing the window display. A program running in a window continues to run in the background when you minimize the window. This is also called ``iconifying.'' See also iconify.

minimize button --
A button in the upper right corner of a window frame that minimizes the window. The button contains an image of a small circle.

missing-picture icon --
An icon that is used when the correct icon picture cannot be located. The icon functions normally even though the correct picture is not displayed.

MMDF --
The Multichannel Memorandum Distribution Facility is one of the Mail Transfer Agents that can be used on SCO systems. MMDF provides transparent access to the different networks and mail transport protocols, regardless of the Mail User Agent employed (one or more MUAs may be used on a single system).

modem --
(programming) A contraction of modulator-demodulator. A modulator converts digital signals from the computer into tones that can be transmitted across phone lines. A demodulator converts the tones received from the phone lines into digital signals so that the computer can process the data.

module --
(programming) 1. A module is a program component that typically contains a function or a group of related functions. Source files and libraries are modules. 2. A STREAMS module consists of two related queue structures, one each for upstream and downstream messages. One or more modules may be pushed onto a stream between the stream head and the driver, usually to implement and isolate a line discipline or a communication protocol.

mosy --
The Managed Object Syntax-compiler (YACC-based) that reads the ASN.1 definitions of a MIB module and produces an output file which can be used by the SMUX library functions. mosy is invoked automatically when you execute the make(1) command.

Motif window manager --
A program that controls window configuration and creates window frames. It is also called mwm.

mount --
A term used to describe the action of connecting a filesystem to your filesystem tree so it is accessible to users on the system. Filesystems can reside on the local hard disk, a floppy disk, a CD-ROM, or on a remote system (if you are using NFS).

mount point --
A location within the directory tree through which a machine accesses a mounted resource. You need to create or specify a mount point when you mount a remote resource. The mount point for a resource is usually an empty directory.

mouse --
A pointing device used to move a pointer about on the screen. See also mouse button.

mouse button --
One of the buttons on a mouse pointing device. The mouse buttons select or manipulate graphical objects. See also click, double-click, drag, and drop.

mouse buttons 1 and 2 --
Button 1 is usually the leftmost button, but this can be changed using the Mouse program. Dragging an icon with mouse button 1 moves the icon. For example, dragging a file icon with mouse button 1 from one directory window to another directory window moves the file the icon represents. Dragging an icon with mouse button 2 copies that icon. For example, dragging a file icon with mouse button 2 from one directory window into another directory window copies the file into the second directory.

mouse pointer --
The graphical image, such as an arrow or other symbol, that indicates your current position on the screen. Move the pointer by moving the mouse. The pointer changes shape to indicate what you can do at a particular location or to indicate a program's status. For example, if a program is busy, the pointer might change to an image of an hourglass.

MTA --
See Mail Transfer Agent.

MUA --
See Mail User Agent.

multipart message --
A message that contains one or more attachments. An attachment might itself be a multipart message containing other attachments.

multiplexor --
(programming) A multiplexor is a driver that allows streams associated with several user processes to be connected to a single driver, or several drivers to be connected to a single user process. STREAMS provides facilities for constructing multiplexors and for connecting multiplexed configurations of streams.

multiprocessor --
A system with more than one central processing unit (CPU).

multiscreen --
A login screen that you can use for an additional work session. Multiscreens provide another way to perform multiple tasks at the same time.

multitasking --
A system that can do several jobs at once.

multithreaded --
A resource is multithreaded if it can be accessed simultaneously by different processors. The kernel is multithreaded to allow equal access by all processes to its tables and the scheduler. Only one copy of the kernel resides in memory.

multiuser --
A system that can be used by more than one person at the same time.


© 2004 The SCO Group, Inc. All rights reserved.
UnixWare 7 Release 7.1.4 - 22 April 2004