open source operating system ppt download

... alterations may take a while on large tables and consume a large amount of the server's CPU and memory resources, it is best to alter tables while few clients are using them. Because ALTER TABLEcopies ... temporary copy of the table when renaming a table Instead, the data files for the table in the file system are simply renamed This is much faster than copying the table, and is unaffected by the amount ... you have installed the MySQL-Max package or explicitly included them when compiling MySQL from source You can also use ALTER TABLEwith other table options Table options allow you to specify various

Ngày tải lên: 03/07/2014, 01:20

... to set a system variable. MYSQL CONFIGURATION OPTIONS 194 The Global Configuration File The global configuration file is read first On UNIX systems, this file is /etc/my.cnf On Windows systems, ... advantages and disadvantages The MySQL monitor and the mysqladminutility are available on all operating systems and provide a consistent interface, while the MySQLGUIand WinMySQLadminutilities provide ... global files are supported: my.ini in the Windows system directory, and my.cnf in the root directory, typically C:\. The User Configuration File On UNIX systems, each user can have their own configuration

Ngày tải lên: 03/07/2014, 01:20

... has all privileges for the entire database MySQL uses its own system of usernames and passwords, unrelated to the underlying operating system You can use the GRANTcommand from MySQL to create a ... Trang 1MySQL includes a sophisticated security system Youcan use MySQL commands to create users and grant them privileges for a database or table. ... are limited to a length of 16 characters There is no limit to password length in MySQL, but some systems limit the length to eight characters While the username and password can be the same as

Ngày tải lên: 03/07/2014, 01:20

... password. After you have opened a connection to the MySQL server, you can use the connection throughout the PHP script If you only have a single connection to a single server open, you can use it ... stays open until your PHP script ends, or until you explicitly close the connection. To close a connection, use the mysql_closecommand and specify the link identifier returned when you opened ... password, and the privileges the user should be assigned for a particular database. You can also open the mysqldatabase directly in phpMyAdminto work with the various security tables Keep in mind

Ngày tải lên: 03/07/2014, 01:20

... Security System We have presented this system as simply a way to read security sensors, but it could be extended to build a complete home alarm system controlled by an Arduino Alarm systems consist ... disarm the system could be the RFID reader project in Chapter 14 Rather than trigger a strike plate, you could have the RFID reader deactivate the security system Of course, an alarm system also ... feedback loop for a control system, such as to control active heating or cooling, or to trigger servos or linear actuators to open and close windows and passive ventilation systems The required parts

Ngày tải lên: 03/07/2014, 20:20

... electrical wall plate to create a touch-sensitive control panel that can link to a home automation system The techniques we describe here should work with pretty much any four-wire resistive touch ... screen is not being touched, the microdots hold the two resistive layers apart to cause it to be an open circuit When the front layer is touched, it distorts and makes contact with the back layer, ... a resistance between them of somewhere around 1K or lower, while nonmatching electrodes will be open-circuit To read one axis of contact with the screen, one of the layers is connected to GND

Ngày tải lên: 03/07/2014, 20:20

... another 32 values mission to the eb site Resources The Magnevation web site, at www.magnevation.com, has an excellent SpeakJet user manual available for download as a PDF The user manual explains ... Water Flow Gauge Determining the consumption of a resource that is measured in units of volume can be more tricky than it sounds Use of resources such as water, gas, and even electricity is typically ... the flow sensor used for this project has what is known as an “open-collector” output This means the output is generally left as an open circuit (unconnected, or floating value with high resistance),

Ngày tải lên: 03/07/2014, 20:20

... easily applied to intercepting data from other devices such as domestic power-consumption monitoring systems Best of all, there’s no modification required to the original device because it just transmits ... can even use it as the basis for making decisions such as sending rainfall data to an irrigation system to minimize water usage For this project we used a weather station from La Crosse, a popular ... might find you can buy just the sensors you want and save some money compared to buying a complete system while also gaining the flexibility of managing the data through an Arduino You can see the

Ngày tải lên: 03/07/2014, 20:20

... of your table cache is sufficient: • Open_tables: This variable stores the number of table schemas opened by all storageengines for all concurrent threads • Open_files: This variable stores the ... actual file descriptors currently opened by the server, for all storage engines • Open_streams: This will be zero unless logging is enabled for the server • Opened_tables: This variable stores ... of table schemas that have beenopened since the server started, across all concurrent threads If the Opened_tables status variable is substantially higher than the Open_tables statusvariable, you

Ngày tải lên: 08/08/2014, 20:21

... functionality,depending on the operating system you use, the interface runs in a very similar fashion on Windows andMacintosh operating systems See http://dev.mysql.com/downloads/for the version for your system Figure ... describes who is responsible for granting access for specific parts of the database Operating System Overview of operating system procedures as they relate to the database Includes information about ... datadata-base Yes, you can find a lot of information about securing database systems, but all systems are not the same Your system presents a unique set of variables What does it mean to be secure?

Ngày tải lên: 08/08/2014, 20:21

... operat-ing system to force MySQL to exit If MySQL won't shut down because it's busy writoperat-ing data and you force it to, you may end up with corrupt or missing data Use the operating system-level ... rather table-like data that is pulled from a variety of sources, including the underlying mysql system database, and the MySQL server system variables and counters In this way, the INFORMATION_SCHEMA ... sec-tion provides more information about data corruption.• Perform troubleshooting tasks on the operating system and hardware A defective disk,damaged RAID controller, or faulty RAM can affect MySQL’s

Ngày tải lên: 08/08/2014, 20:21

... threecolor components), and because it is a color system with which many program-mers and end users are familiar with (it’s common to several operating systems).The BeOS defines rgb_color as a struct ... of 256 colors A pixel value in the range of 0 to 255 is used as an index into a color map This system color map isidentical for all applications That means that when two programs use thesame ... defining analpha byte, which is used to specify a transparency level for a color Trang 3RGB Color SystemAs listed above, the BeOS supports a number of color spaces The RGB colorspace is popular

Ngày tải lên: 26/01/2014, 07:20

... messages and handle them.For the most part, system messages are handled automatically; for instance, when a B_ZOOM message is received, the operating system zooms the window But youcannot completely ... Application Server delivers a system message to an applicationwindow, that message arrives in the form of a BMessage object Your code deter-mines how to handle a system message simply by overriding ... 10When the program refers to a system message by its Be-defined constant, such asB_QUIT_REQUESTED or B_KEY_DOWN, what’s really of interest is the what datamember of the system message The value of

Ngày tải lên: 26/01/2014, 07:20

... the results is often useful, but it is less vital if a server shows an open port inside your network than if it shows one open from out-side the firewall • You may want to run your scans early ... attacks Bold black These are services that can provide some information about the machine or operating system such as finger, echo, and so on Plain black Any other services or ports identified Figure ... directory and, using a text editor program such as vi or EMACS, open the file installer.sh and enter the variables where indicated for your system N l o g : A T o o l f o r S o r t i n g a n d O r g

Ngày tải lên: 04/07/2014, 13:20

... about system stability It’s a well-known fact that when systems vendors issue patches, they sometimes fix one thing and break two others For mission-critical systems, finding the time and resources ... firewalls sit on top of regular operating systems, such as Win-dows or UNIX, and thus can be vulnerable to all the normal OS-level exploits Even if the firewall operating system is proprietary, exploits ... Internet and makes them an extension of your systems to external users However, doing this opens up a big potential source of vulnerabilities These are often systems that have not been hardened for

Ngày tải lên: 04/07/2014, 13:20

... 1316 Trang 2Gain root remotely OpenSSH Channel Code Off by 1 CVE-2002-0083 4241 Gain root remotely Buffer overflow in FreeBSD 2.x lpd CVE-1999-0299 Gain root remotely OpenSSH UseLogin Environment ... 2811, 4055, 4295, 4614 Gain root remotely IIS buffer overflow CVE-1999-0874 307 Gain root remotely OpenSSH < 2.1.1 UseLogin feature CVE-2000-0525 1334 Gain root remotely BIND 4.x resolver overflow ... CVE-2002-0149 4485 Gain root remotely snmpXdmid overflow CVE-2001-0236 2417 Gain root remotely PPTP overflow CAN-2003-0213 7316 Gain root remotely HTTP version number overflow Gain root remotely

Ngày tải lên: 04/07/2014, 13:20

... for children and zombies now follow.The owner of a code segment is recorded here This allows the system todetermine which process owns any segment of code when swapping occurs code owners
= code ... other processes, so the con-stant devprocqueue denotes the queue of highest-priority processes System processes must be preferred by the scheduler to user processes but should be pre-empted by ... LowLevelScheduler It is defined as follows The scheduler has three queues (readyqs), one each for device, system and user process (in that order) It is worth noting that the process queues are all contained

Ngày tải lên: 23/07/2014, 23:20

... (you’ll find the sourcecode and makefile for this program in the accel directory of the sample source archive): /* main.c Demonstration applet for E2BUS stepper interface code From “Open-Source Robotics ... int main (int _argc, char *_argv[]) { unsigned char pkt[6]; int i=0,j; // Open port if (E2B_Acquire()) { printf(“Error opening E2BUS.\n”); Trang 2printf(“Reset complete, pausing \n”); sleep(1); ... instead of an external crystal This application also provides a nice example of how the sorts of systems in this book can be used in real-world situations. I developed this device for a shipping

Ngày tải lên: 10/08/2014, 05:20

... Unfortunately, this system was relatively easy to break, to one degree or another Because the structure of a DOS-formatted disk contains many snippets of data with meanings defined by the operating system, ... protect against ■ Resources available to you This includes any special restrictions on your sys-tem; power or duty cycle limitations, available CPU horsepower, and so on ■ Resources available ... to inhibit free discussion of such cryptosystems For a practical example of this, you need look no further than the debacle about DeCSS, the encryption system used on commercial DVDs The upshot

Ngày tải lên: 10/08/2014, 05:20

... of course, a downloadarea where you can obtain the program After downloading the distribution file, you must uncompress and expand it into a working directory Depending on your Unix system, this ... or later systems, use the pstat() function to compute CPU performance. -DUSE_KSTAT For Solaris 2.x systems, use the kstat interface to compute CPU performance. -DUSE_PROC_STAT For Linux systems, ... erased ifthe system is rebooted The default CFLAGS line is set for compiling netperf on an HP Unix system.You must modify this value for it to compile on any other type of Unix system An example

Ngày tải lên: 14/08/2014, 12:20