asp.net scan barcode android 33: Devices and Printers in Software

Maker QR in Software 33: Devices and Printers

33: Devices and Printers
QR Code ISO/IEC18004 Reader In None
Using Barcode Control SDK for Software Control to generate, create, read, scan barcode image in Software applications.
QR Code Generation In None
Using Barcode maker for Software Control to generate, create QR Code 2d barcode image in Software applications.
Overview
QR Code ISO/IEC18004 Reader In None
Using Barcode recognizer for Software Control to read, scan read, scan image in Software applications.
Quick Response Code Encoder In C#.NET
Using Barcode generator for .NET Control to generate, create QR Code image in .NET applications.
All devices, such as printers, terminals, and CD-ROMs, are connected to your Linux operating system through special files called device files. Such a file contains all the information your operating system needs to control the specified device. This design introduces great flexibility. The operating system is independent of the specific details for managing a particular device; the specifics are all handled by the device file. The operating
Quick Response Code Creation In VS .NET
Using Barcode creation for ASP.NET Control to generate, create QR-Code image in ASP.NET applications.
Generating QR Code ISO/IEC18004 In .NET
Using Barcode creation for .NET framework Control to generate, create Quick Response Code image in Visual Studio .NET applications.
system simply informs the device what task it is to perform, and the device file tells it how. If you change devices, you only have to change the device file, not the whole system. To install a device on your Linux system, you need a device file for it, software configuration such as provided by a configuration tool, and kernel support usually supplied by a module or already built into the kernel. An extensive number of device files are already set up for different kinds of devices. You usually only need to choose one of these. For kernel support, you may have to load a kernel module or recompile the kernel, both simple procedures. In most cases, support is already built into the kernel. Configuration of your device may be provided by desktop configuration tools such as the Gnome Control Center, system configuration tools such as Linuxconf, or a module configuration interface such as that provided for sound modules by sndconfig.
Encode Quick Response Code In Visual Basic .NET
Using Barcode generator for .NET framework Control to generate, create QR-Code image in .NET applications.
Print UPC - 13 In None
Using Barcode printer for Software Control to generate, create EAN13 image in Software applications.
Device Files
Print Bar Code In None
Using Barcode creator for Software Control to generate, create barcode image in Software applications.
Paint Code 39 In None
Using Barcode maker for Software Control to generate, create Code 3/9 image in Software applications.
The name of a device file is designed to reflect the task of the device. Printer device files begin with lp for "line print." Because you could have more than one printer connected to your system, the particular printer device files are distinguished by two or more numbers or letters following the prefix lp, such as lp0, lp1, lp2. The same is true for terminal device files. They begin with the prefix tty, for "teletype," and are further distinguished by numbers or letters such as tty0, tty1, ttyS0, and so on. You can obtain a complete listing of the current device filenames and the devices for which they are used from the kernel.org Web site at http://www.kernel.org/pub/linux/docs/device-list/devices.txt. All of these filenames will be implemented as device files in your /dev directory. Here you can find printer, CD-ROM, hard drive, SCSI, and sound device files, along with many others. Certain link files bear common device names that are often linked to the actual device file used. For example, a /dev/cdrom symbolic link links to the actual device used for your CDROM. If your CD-ROM is an IDE device, it may use the device file hdc. In this case, /dev/cdrom would be a link to /dev/hdc. In effect, /dev/cdrom is another name for /dev/hdc. You can use /dev/cdrom to reference your CD-ROM's device file, instead of /dev/hdc. A /dev/modem link file also exists for your modem. If your modem is connected to the second serial port, its device file would be /dev/ttyS1. In this case, /dev/modem would be a link to that device file. Applications can then use /dev/modem to access your modem, instead of having to know the actual device file used. A listing of commonly used device links is shown in Table 33-1. Table 33-1: Device Links Description Current mouse device Current tape device Current CD-ROM device Current CD-writer device Current scanner device Current dial-out device, modem port Current root file system Current swap device
Code 128C Creation In None
Using Barcode drawer for Software Control to generate, create Code 128 Code Set A image in Software applications.
GTIN - 12 Creation In None
Using Barcode creator for Software Control to generate, create UPCA image in Software applications.
Link /dev/mouse /dev/tape /dev/cdrom /dev/cdwriter /dev/scanner /dev/modem /dev/root /dev/swap
Print RoyalMail4SCC In None
Using Barcode creation for Software Control to generate, create British Royal Mail 4-State Customer Barcode image in Software applications.
Barcode Printer In Visual Basic .NET
Using Barcode encoder for .NET Control to generate, create barcode image in Visual Studio .NET applications.
Note You will notice that there are no entries for the Ethernet devices in the /dev file, such as eth0 or eth1. That is because these are really aliases for kernel modules defined in the /etc/modules.conf file. They are not device files. Two types of devices are implemented in Linux: block and character. A block device, such as a hard disk, transmits data a block at a time. A character device, such as a printer or modem, transmits data one character at a time, or rather as a continuous stream of data, not as separate blocks. Device driver files for character devices have a c as the first character in the permissions segment displayed by the ls command. Device driver files for block devices have a b. In the next example, lp0 (the printer) is a character device and hda1 (the hard disk) is a block device:
Barcode Creator In Java
Using Barcode generator for Android Control to generate, create barcode image in Android applications.
Barcode Encoder In Visual Studio .NET
Using Barcode printer for Reporting Service Control to generate, create bar code image in Reporting Service applications.
# ls -l hda1 lp0 brw-rw---- 1 root disk 3, 1 Sep 7 1994 hda1 crw-r----- 1 root daemon 6, 0 Dec 31 1979 lp0
Print Code-128 In None
Using Barcode maker for Font Control to generate, create Code 128 Code Set C image in Font applications.
GS1 - 12 Reader In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
Although most distributions include an extensive set of device files already set up for you, you can create your own. You use the mknod command to create a device file, either a character or block type. The mknod command has the following syntax:
DataMatrix Generator In None
Using Barcode printer for Online Control to generate, create Data Matrix 2d barcode image in Online applications.
USS-128 Maker In Objective-C
Using Barcode creator for iPad Control to generate, create UCC - 12 image in iPad applications.
Copyright © OnBarcode.com . All rights reserved.