Linux and UNIX Man Pages

Linux & Unix Commands - Search Man Pages

cn_get_magic(9) [netbsd man page]

CNMAGIC(9)						   BSD Kernel Developer's Manual						CNMAGIC(9)

NAME
cn_init_magic, cn_trap, cn_isconsole, cn_check_magic, cn_destroy_magic, cn_set_magic, cn_get_magic -- console magic key sequence management SYNOPSIS
#include <sys/systm.h> void cn_init_magic(cnm_state_t *cnms); void cn_trap(); int cn_isconsole(dev_t dev); void cn_check_magic(dev_t dev, int k, cnm_state_t *cnms); void cn_destroy_magic(cnm_state_t *cnms); int cn_set_magic(char *magic); int cn_get_magic(char *magic, int len); DESCRIPTION
The NetBSD console magic key sequence management framework is designed to provide flexible methods to set, change, and detect magic key sequences on console devices and break into the debugger or ROM monitor with a minimum of interrupt latency. Drivers that generate console input should make use of these routines. A different cnm_state_t should be used for each separate input stream. Multiple devices that share the same input stream, such as USB keyboards can share the same cnm_state_t. Once a cnm_state_t is allocated, it should be initialized with cn_init_magic() so it can be used by cn_check_magic(). If a driver thinks it might be the console input device it can set the magic sequence with cn_set_magic() to any arbitrary string. Whenever the driver receives input, it should call cn_check_magic() to process the data and determine whether the magic sequence has been hit. The magic key sequence can be accessed through the hw.cnmagic sysctl variable. This is the raw data and may be keycodes rather than pro- cessed characters, depending on the console device. FUNCTIONS
The following functions describe the console magic interface. cn_init_magic(cnm) Initialize the console magic state pointed to by cnm to a usable state. cn_trap() Trap into the kernel debugger or ROM monitor. By default this routine is defined to be console_debugger() but can be overridden in MI header files. cn_isconsole(dev) Determine whether a given dev is the system console. This macro tests to see if dev is the same as cn_tab->cn_dev but can be over- ridden in MI header files. cn_check_magic(dev, k, cnms) All input should be passed through cn_check_magic() so the state machine remains in a consistent state. cn_check_magic() calls cn_isconsole() with dev to determine if this is the console. If that returns true then it runs the input value k through the state machine. If the state machine completes a match of the current console magic sequence cn_trap() is called. Some input may need to be translated to state machine values such as the serial line BREAK sequence. cn_destroy_magic(cnms) This should be called once what cnms points to is no longer needed. cn_set_magic(magic) cn_set_magic() encodes a nul terminated string arbitrary string into values that can be used by the state machine and installs it as the global magic sequence. The escape sequence is character value 0x27 and can be used to encode special values: 0x27 The literal value 0x27. 0x01 Serial BREAK sequence. 0x02 Nul character. Returns 0 on success or a non-zero error value. cn_get_magic(magic, len) Extract the current magic sequence from the state machine and return up to len bytes of it in the buffer pointed to by magic. It uses the same encoding accepted by cn_set_magic(). Returns 0 on success or a non-zero error value. SEE ALSO
sysctl(8), cons(9) HISTORY
The NetBSD console magic key sequence management framework first appeared in NetBSD 1.6. AUTHORS
The NetBSD console magic key sequence management framework was designed and implemented by Eduardo Horvath <eeh@NetBSD.org>. BSD
June 8, 2010 BSD

Check Out this Related Man Page

fileutil::magic::cgen(n)					  file utilities					  fileutil::magic::cgen(n)

__________________________________________________________________________________________________________________________________________________

NAME
fileutil::magic::cgen - Generator core for compiler of magic(5) files SYNOPSIS
package require Tcl 8.4 package require fileutil::magic::cgen ?1.0? package require fileutil::magic::rt ?1.0? package require struct::tree package require struct::list ::fileutil::magic::cgen::2tree script ::fileutil::magic::cgen::treedump tree ::fileutil::magic::cgen::treegen tree node _________________________________________________________________ DESCRIPTION
This package provides the generator backend for a compiler of magic(5) files into recognizers based on the fileutil::magic::rt recognizer runtime package. For the compiler frontend using this generator see the package fileutil::magic::cfront. COMMANDS
::fileutil::magic::cgen::2tree script This command converts the recognizer specified by the script into a tree and returns the object command of that tree as its result. It uses the package struct::tree for the tree. The script is in the format specified by magic(5). ::fileutil::magic::cgen::treedump tree This command takes a tree as generated by ::fileutil::magic::cgen::2tree and returns a string encoding the tree for human consump- tion, to aid in debugging. ::fileutil::magic::cgen::treegen tree node This command takes a tree as generated by ::fileutil::magic::cgen::2tree and returns a Tcl script, the recognizer for the file types represented by the sub-tree rooted at the node. The generated script makes extensive use of the commands provided by the recognizer runtime package fileutil::magic::rt to perform its duties. BUGS, IDEAS, FEEDBACK This document, and the package it describes, will undoubtedly contain bugs and other problems. Please report such in the category fileutil :: magic of the Tcllib SF Trackers [http://sourceforge.net/tracker/?group_id=12883]. Please also report any ideas for enhancements you may have for either package and/or documentation. SEE ALSO
file(1), fileutil, magic(5) KEYWORDS
file recognition, file type, file utilities, mime, type fumagic 1.0 fileutil::magic::cgen(n)
Man Page