Editing AmigaDOS (section)

==Syntax of AmigaDOS commands==
This is an example of typical AmigaDOS command syntax:

<syntaxhighlight lang="doscon">
1> Dir DF0:
</syntaxhighlight>

:Without entering the directory tree, this shows the content of a directory of a floppy disk and lists [[subdirectories]] as well.

<syntaxhighlight lang="doscon">
1> Dir SYS: ALL
</syntaxhighlight>

:The argument "''ALL''" causes the command to show the entire content of a volume or device, entering and expanding all directory trees. "''SYS:''" is a default name that is assigned to the boot device, regardless of its physical name.<ref>{{harvnb|Commodore-Amiga Inc.|1986}}</ref>

===Command redirection===
AmigaDOS can redirect the output of a command to files, pipes, a printer, the null device, and other Amiga devices.

<syntaxhighlight lang="doscon">
1> Dir > SPEAK: ALL
</syntaxhighlight>

:Redirects the output of the "''dir''" command to the speech synthesis handler. The colon character "'':''" indicates that ''SPEAK:'' points to an AmigaDOS device. While a typical use for a device is [[file system]]s, special-purpose device names such as this are commonly used in the system.

===Command template===
AmigaDOS commands are expected to provide a standard "template" that describes the arguments they can accept. This can be used as a basic "help" feature for commands, although third-party replacement console handlers and [[Shell (computing)|shells]], such as [[Bash (Unix shell)|Bash]] or [[Zshell]] (ported from [[Unix]]), or KingCON often provide more verbose help for built-in commands.

On requesting the template for the command "''Copy''", the following output is obtained:

<syntaxhighlight lang="doscon">
1> Copy ?
   FROM, TO/A, ALL/S, QUIET/S
</syntaxhighlight>

:This [[string (computer science)|string]] means that the user must use this command in conjunction with ''FROM'' and ''TO'' arguments, where the latter is compulsory ({{mono|/A}}). The argument keywords ''ALL'' and ''QUIET'' are switches ({{mono|/S}}) and change the results of the command ''Copy'' (''ALL'' causes all files in a directory to be copied, while ''QUIET'' will cause the command to generate no output).

By reading this template, a user can know that the following syntax is acceptable for the command:

<syntaxhighlight lang="doscon">
1> Copy DF0:Filename TO DH0:Directory/Filename
</syntaxhighlight>

===Breaking commands and pausing console output===
A user can terminate a program by invoking the key combination {{keypress|Ctrl|C}} or {{keypress|Ctrl|D}}. Pressing {{keypress|space}} or any printing character on the keyboard suspends the console output. Output may be resumed by pressing the {{keypress|backspace}} key (to delete all of the input) or by pressing {{keypress|enter}} (which will cause the input to be processed as a command as soon as the current command stops running).

===Wildcard characters===
Like other operating systems, AmigaDOS also provides [[wildcard character]]s that are substitutes for any character or any sequence of random characters in a string. Here is an example of wildcard characters in AmigaDOS commands:

<syntaxhighlight lang="doscon">
1> Dir #?.info
</syntaxhighlight>

:searches the current directory for any file containing ".info" at its end as suffix, and displays only these files in the output.

The parsing of this is as follows. The "?" wildcard indicates "any character". Prefixing this with a "#" indicates "any number of repetitions". This can be viewed as analogous to the [[regular expression]] ".*".