zebra barcode printer vb net 10: Managing Linux Processes and Services in Software

Creation Code-128 in Software 10: Managing Linux Processes and Services

10: Managing Linux Processes and Services
Drawing Code 128 Code Set A In None
Using Barcode creator for Software Control to generate, create Code 128C image in Software applications.
Code 128 Code Set C Reader In None
Using Barcode reader for Software Control to read, scan read, scan image in Software applications.
TABLE 10-1
Encoding Code128 In Visual C#
Using Barcode generation for .NET Control to generate, create Code-128 image in .NET applications.
Drawing Code 128 Code Set B In .NET
Using Barcode maker for ASP.NET Control to generate, create Code 128 Code Set B image in ASP.NET applications.
Linux Programs
Painting Code 128 Code Set B In .NET
Using Barcode printer for VS .NET Control to generate, create Code 128C image in .NET framework applications.
Code 128A Drawer In VB.NET
Using Barcode generator for .NET framework Control to generate, create Code 128 image in Visual Studio .NET applications.
Type of Program
Make EAN / UCC - 13 In None
Using Barcode generation for Software Control to generate, create EAN-13 image in Software applications.
UPC-A Supplement 2 Maker In None
Using Barcode encoder for Software Control to generate, create UPC Symbol image in Software applications.
Binary executables
Bar Code Maker In None
Using Barcode creator for Software Control to generate, create barcode image in Software applications.
Printing Code128 In None
Using Barcode drawer for Software Control to generate, create Code-128 image in Software applications.
Description
GTIN - 128 Creation In None
Using Barcode generator for Software Control to generate, create EAN128 image in Software applications.
Code-39 Creator In None
Using Barcode maker for Software Control to generate, create Code-39 image in Software applications.
These are programs that were originally created as a text file using a programming language, such as C or C++ The text file was then run through a compiler to create a binary file that can be processed by the CPU Remember when you learned how to install applications from source code in a previous chapter You were using a compiler (gcc) to compile the text file you downloaded into a binary executable Some of the commands you enter at the shell prompt are actual binary files in the file system that are loaded and run by the CPU For example, when you enter rpm at the shell prompt, you load the rpm binary file into memory Other commands, however, are not binary executables Instead, they are commands that are rolled into the shell program itself For example, if you enter exit at a shell prompt, you are actually running an internal shell command There is no executable file in the file system named exit Instead, the computer code associated with the exit function is stored within the shell program code itself These are text files that are executed through the shell itself You can include commands to run binary executables within the text of any shell script You created shell scripts in the previous chapter
Code11 Creator In None
Using Barcode creation for Software Control to generate, create Code 11 image in Software applications.
UCC.EAN - 128 Maker In Visual C#
Using Barcode creator for VS .NET Control to generate, create EAN 128 image in Visual Studio .NET applications.
Internal shell commands
Code128 Reader In Visual Basic .NET
Using Barcode decoder for VS .NET Control to read, scan read, scan image in .NET framework applications.
Generating Code 3 Of 9 In VS .NET
Using Barcode generation for ASP.NET Control to generate, create Code 39 image in ASP.NET applications.
Shell scripts
Paint EAN13 In VS .NET
Using Barcode creator for VS .NET Control to generate, create EAN 13 image in VS .NET applications.
Create EAN13 In Java
Using Barcode maker for Java Control to generate, create European Article Number 13 image in Java applications.
In the preceding paragraph, I put the term concurrently in quotes because most CPUs can t truly run multiple processes at the same time Instead, the Linux operating system quickly switches between the various processes running on the CPU, making it appear as if the CPU is working on multiple processes concurrently However, the CPU actually only executes a single process at a time All other currently running processes wait in the background for their turn The operating system maintains a schedule that determines when each process is allowed access to the CPU This is called multitasking Because the switching between processes happens so fast, it appears, to you and me at least, that the CPU is executing multiple processes at the same time Newer, dual-core CPUs can actually execute more than one process at a time Because there are two cores within the CPU, one core can execute one process while the other core works on another
GS1 DataBar Truncated Printer In Visual Studio .NET
Using Barcode generation for VS .NET Control to generate, create GS1 DataBar Expanded image in .NET applications.
Generate Barcode In Objective-C
Using Barcode generation for iPhone Control to generate, create barcode image in iPhone applications.
Describe How Linux Handles Processes
The Linux operating system uses several types of processes Let s review those next
Types of Processes
Not all processes on your Linux system are the same Some processes are created by the end user when he or she executes a command from the shell prompt or though the X Windows graphical interface These processes are called user processes User processes are usually associated with some kind of end-user program running on the system For example, if you were to run the OpenOfficeorg suite (oofromtemplate) from the shell prompt to create a spreadsheet, two user processes for the OpenOfficeorg program would be created This is shown in Figure 10-1 The key point to remember about user processes is that they are called from within a shell and are associated with it However, not all processes running on your system are user processes In fact, most processes executing on a given Linux system will probably be of a different type called system processes or daemons Unlike a user process, a system process (usually) does not provide an application for an end user to use Instead, they are used to provide system services, such as a Web server, an FTP server, a file service such as Samba, a print service such as CUPS, a logging service, and so on These processes run in the background and usually don t provide any kind of user interface For example, consider the processes shown in Figure 10-2 Notice that the system has many system processes running, including cupsd, hald, resmgrd, mdsnd, auditd, cron, qmgr, sshd, powersaved, and xinetd System processes are usually (but not always) noted with a d at the end of the name, which stands for daemon
FIGURE 10-1
Copyright © OnBarcode.com . All rights reserved.