Linux99 (below)

4. "powerful weapons" in Linux: Question 15

55. What is KDE and what are its characteristics?
The KDE Project was launched in October 1996 to create a complete and easy-to-use desktop environment on X-window. KDE now has kfm (similar to ie4.0), kpresenter (similar to PowerPoint), killustrator (similar to CorelDraw or illustrator) and other heavyweight software, there are also considerate user GUI configuration software that can help users configure Unix/Linux, so that they are very popular.
However, because KDE is developed based on QT Program Library, so it was also criticized. Although QT itself is an excellent cross-platform development tool based on C ++, it is a pity that it is not a free software. Qt's license allows anyone to use QT to write free software and copy it to other users for free. However, if you use QT to write non-free software, you need to purchase their license. More importantly, no one can modify QT at will. Source code . If trolltech changes its QT license, the company goes bankrupt, or makes acquisitions, it will make KDE useless.
56. What is gnome and what are its characteristics?
In August 1997, 250 programmers headed by Miguel de Icaza in Mexico started a new project to overcome the difficulties encountered by KDE In the QT License Agreement and single c ++ dependency, this is gnome.
After 14 months of joint efforts, the project was finally completed. Now gnome has received support from red hat, the largest distributor in the Linux market. It has a large number of applications, including the go, gnumeric, and gnomecal, similar to Photoshop, gimp is a graphic image processing software.
Now gnome and KDE have become two major competitors, making Linux easier to use.
57. How to play a CD in Linux?
After you successfully drive your sound card in Linux, you can use a CD player in X-window to play the CD, which is used in multimedia tools.
58. Can I play VCD in Linux?
You can use the VCD player of mpegtv Player 1.0 in Linux to achieve your wish.
You only need to run X Window to install mpegtvplayer without special hardware devices.
It imitates the playback control key of the video recorder, for example: playback, fast forward, fast return, stop, search, volume adjustment, static sound, Volume balancing, loop playback, screen zoom in and out, automatic playback, etc. The playback process displays the time and time used for the entire program.
You can download mpegtv play: http://www.mpegtv.com at the following site.
59. Is there any mp3 playing tool in Linux?
There are many MP3 playing tools in Linux, among which mpg123 should be the most classic and can be used on the console. Many graphic MP3 playback software use this program to play MP3 videos. Below are some of its basic parameters:
-A device is used to set the sound device to/dev/audio or/dev/DSP.
-@ File: reads the list of MP3 file names to be played from the file.
-Z: Random playback
If you want to simply play one or two songs or play a song in the entire directory, using mpg123 is a good choice, for complex functions such as selecting a specific MP3 file in multiple directories, you may need to write a script for execution.
60. How can I browse webpages in Linux?
To browse a webpage, you must meet the following two conditions:
1) Your computer is connected to the Internet;
2) use browser software for browsing. There are two common browsers in Linux:
You can use lynx in the console;
Linux version of Netscape can be used in X-window;
They are used in a similar way as browsers in windows.
61. How to send and receive e-mail in Linux
In Linux, you can use mail and Pine to send and receive e-mail under the console command line. In X-window, you can use kmail to receive e-mail.
62. Can I display Chinese Characters in Linux?
In the English version of Linux, you can install the Chinese analog terminal chdrv to enable Linux to display and Chinese characters in the command line status. After chdrv is started, a virtual terminal is created in tty7 (CTRL + ALT + F7). After logging on to tty7, you can use the Chinese support provided by the virtual terminal.
To begin:

Tar xvzf chdrvbin-0.23.gb.tar.gz
Music chdrvfont.tar.gz chdrv-0.23.gb/
CD chdrv-0.23.gb into this directory
./Installbin run the Installation File

63. Is there any Chinese Input Method in Linux?
If you are using the Chinese version of Linux, you do not need to install it. If you use the English version of Linux, you can install chinput to implement Chinese input. You can download to the following url: http://www.turbolinux.com.cn /~ Justiny/download/chinput-2.1.tar.gz
1) After the download, unbind the file: tar-xvzf chinput-2.1.tar.gz
2) After unlocking, enter the Chinput-2.1/src, modify the chinput. c file, find the words GBK, change it to gb2312. Find the system ("/usr/bin/zwincontrol &"); Statement and cancel it (add // before it //);
3) after modification, execute the make command to compile;
4) after compilation, you can use it in the X-Window environment.
64. Is there any text editing software besides Vi?
VI is the most common editing software in Unix/Linux environments, but it is not very friendly. If you are not satisfied with it, try other editing tools such as Emacs and Joe.
I strongly recommend Emacs, a masterpiece of Stallman, the father of FSF, and the first blockbuster of the GNU project. It is indeed very good and worth a try. But the biggest drawback is that it is too complicated.
65. Is there any software like office in Linux?
Yes, StarOffice is an office software package based on Linux. It is a commercial software package, including software included in MS Office software such as word processing, workbooks, and slide making. A free version is provided for individual users. Users can download from the following sites: http://studio.linux.org.cn.
StarOffice office suite for Linux is prepared for non-commercial users. Commercial users need a license to use StarOffice. Ftp://ftp.gwdg.de/pub/linux/staroffice
66. Is there any software like Photoshop in Linux?
Yes, there is a very famous graphic processing software-gimp in Linux. Its interface is more concise than Photoshop, and there is only one toolbar at startup, which looks similar to Photoshop. the main menu is displayed only when you right-click an opened image, such as channels, layers, brushes ...... the appearance is similar to that of Photoshop, so you don't need to take the time to adapt .....
This is not a feature. there are many advantages over Photoshop: for example, the image format is extremely large, texture brush is supported, and the shading pattern is flushed out like painter. there are more filters. For example, there is a kind of algorithm called Alien map that performs sin and cos operations on RGB to achieve special effects. the Undo function is also good. I tried it and supported at least five undo operations. what's even more exciting is the support for Web, which allows you to easily create custom arrows, buttons, and background patterns, which are more powerful than photoimpact.
If you can't leave Photoshop, you can't afford the Adobe treasurer's account, and you think that you don't need the dashboard for art players, try gimp!
67. Can I play games in Linux?
Now we have a game for Linux, in addition to the well-known doom, we also use ACM-air combat simulation games, xdemineur-mining mines, xjewel-Tetris, xboard-chess, and xboing-pinball games. And now more and more, add a bit of fun for you in the boring learning.
68. Is there a C language in Linux? What about other languages?
GCC, a blockbuster created by FSF, a free software fund in Linux, is a powerful compiler and is currently the most efficient C/C ++ compiler in the world, it has been widely used in various UNIX environments. Although there is no integrated development environment for C language, it does not affect the popularity of GCC. This may be the power of freedom!
In Linux, it also supports Fortran, Pascal, Perl, COBOL, and other languages.
69. What database software does Linux have?
There are many types of database software available in Linux, including Oracle for Linux, IBM DB2 for Linux, MySQL, msql, and post.

5. Do a good job as a Linux administrator: 21

70. How can I check Linux hard disk usage?
In Linux, you can use the DF command to view the hard disk usage. The following is an input example of a DF-t-h (-t parameter: displays the file system type, and the-h Parameter displays information in a readable way) command:

Filesystem type size used avail use % mountedon
/Dev/hda1 ext2 7.5g 4.7G 2.5g 65%/
/Dev/hda2 ext2 653 M 6.6 m 613 M 1%/root
/Dev/hdb1 ext2 7.5g 3.5G 3.7g 49%/usr

71. What compression tools are available in Linux?
There are many compression tools in Linux, commonly used:
1) gzip/gunzip: this is a free software developed by GNU and widely used. The extension name of the compressed file is 2.16.gz ". The usage is simple, for example:

Gunzip eos.gz
Gzip/home/test/*. txt;

2) compress/uncompress: This is a history compression program. After a file is compressed, the compressed file extension is ". Z ".
3) In addition, zip, unzip, Bzip2, and bunzip2 are supported.
72. How to manage processes?
A process is an execution of a program. You can use "PS-auxw" to list the details of the processes currently being executed, including the ID of each process. You can use the "kill process ID" to terminate the process.
73. What does file or directory permission mean?
the file or directory permission bit consists of 10 digits, for example,-rwxr-XR-X.
1) first represents the file/directory type: D represents the directory,-represents the file, and l represents the link;
2) the remaining 9 digits are divided into three groups, 3 Characters in each group; 2-4 characters describe the permissions of the file owner. 5-7 characters describe the permissions of the same user group as the file owner, and 8-10 characters describe the permissions of other users.
3) rwx: The three digits in each group are: Read Permission, write permission, and execution permission. If yes-, this permission is unavailable.
-rwxr-XR-X indicates that this is a common file. The file owner can read, write, and execute this file, users in the same group as the file owner and other users can read and execute the file.
74. What is a user account?
in Linux, a user account is used to identify each user. During logon, you can enter a different user account and password to determine your identity. In other words, Linux uses user accounts and all users of the management system.
then you can create some user groups and add users to the groups to grant them the permissions of the user groups.
75. in Linux, how do I manage users?
if you want to add a new user:
1) Log On As root, and then run "adduser User Account Name"
2) run "passwd User Account Name" to set a password for this user account.
execute "userdel User Account" to delete a user.
execute "groupadd user group name" to add a user group.
execute "groupdel user group name" to delete a user group;
76. how do I set a disk quota for users?
1) modify the/etc/fstab file in the following format for the partition where the disk quota is to be set:
/dev/hda2/home ext2 defaults, usrquota 1 2
2) create an empty file named quota in the partition directory where you want to set the disk quota. user

# Touch/home/quota. User
# Chmod 600/home/quota. User

3) after the system is restarted, you can use the edquota-u user name to set it.
77. How do I back up the system?
In Linux, you can use the dump/restore Command Group to back up and restore the system. Assume that you need to completely back up all files in the/usr directory to the tape drive (assuming the device is rmt8, different tape drives are different), you can run the following command:

Dump-o-F/dev/rmt8/usr

The-O parameter indicates that all files are backed up. The "-F Device File Name" parameter specifies the backup location and the last directory name specifies the content to be backed up.
Then, you can use the following command to restore:

Restore-r-F/dev/rmt8

78.how to install the .tar software package?
There are two methods to release Linux software: one is sourceCodeMethod, the other is the executable file package. The archive file first uses the tardocuments, and then uses the gzipcompressed file to generate the file ended with .tar.gz.
You can decompress the package directly using "Tar xvfz file name.
If you get an executable package, the installation is complete.
If you get the source code package, you need to compile it again:
1) Run "./configure" in the extract directory for configuration;
2) Run "make" in the decompressed directory to compile;
3) Run "make install.
79. How to Use RPM to install linux software?
The RPM tool provided by RedHat makes it easier to install linux software.
1) installation: rpm-IVH somesoft. rpm
2) reverse installation: rpm-e somesoft. rpm
3) query: rpm-Q somesoft
80. What should I do if I forget the root password? If you forget the root password, use the following methods to restore it:
1) Restart Linux. When lilo is displayed: Enter linuxsingle to enter the single user mode;
2) The root permission is obtained without a password;
3) Run passwd to reset the root password.

81. What should I do when I reinstall windows and destroy lilo?
In this case, you can use two methods to restore:
1) Start the disk in Linux, execute/sbin/Lilo, and create lilo again in the boot area;
2) use the Linux installation CD to start and select upgrade system. Lilo will be rebuilt.
82. How to Create a Linux boot disk?
In Linux, there is a mkbootdisk tool that can easily create a system boot disk:
1) view the system version, which can be viewed through ls/usr/src;
2) Insert an empty floppy disk;
3) Run "mkbootdisk -- verbose 2.2.5 ".
83. How to remotely use Linux?
We can use commands such as telnet, rlogin, RSH, and rcp to remotely use Linux. However, these methods are transmitted in plaintext during transmission, which may lead to many insecure factors. Therefore, try to avoid remotely using the root account to log on to the system.
How to Build Secure Remote logon?
SSH is used for secure remote login, because SSH implements data transmission encryption.
1) obtain the ssh-1.26.tar.gz file from ftp. cs. HTU. fi/pub/ssh;
2) use tar xvpf ssh-1.26.tar.gz to unlock this package;
3) to the Undo directory/usr/local/src/ssh-1.26 directory to execute./configure;
4) execute make and make install to complete compilation and installation.
5) You can use SSH to establish a secure remote connection with the server installed with SSH.
85. How do I run a scheduled task?
You may be familiar with scheduled tasks in windows. You can perform scheduled tasks through some simple settings. In the maintenance of Linux, we can also execute some tasks on a regular basis. In this case, we can use:
1) At command: It can read commands on the keyboard or file and then execute the commands at the specified time;
2) crontab waiting process: You can set its configuration file to regularly execute certain tasks.
86. What did Linux do during the boot process?
1) when the host is started, the CPU will give control to the bios, And the BIOS will complete the self-check;
2) then the BIOS reads the first sector on the disk and loads the Lilo of the Main Boot Sector;
3) lilo selects a different kernel Image Based on the input. If you select Linux, it reads the core image under/boot;
4) The core starts hardware detection and device driver initialization, and then runs init
5) The INIT process runs a series of initialization scripts based on the/etc/inittab configuration;
6) Start the Getty process to receive user logon.
87. How do I set the program to run automatically upon startup?
You can add the command you want to execute as soon as you start the system in the following script files:

/Etc/rc. Local
/Etc/rc. sysinit
/Etc/rc. d/init. d.

88. Why do we need to re-compile the kernel?
In the following cases, you need to re-compile the kernel or add the dynamic kernel module:
1) Update the driver;
2) customize the most reliable kernel based on your needs;
3) Upgrade the Linux kernel.
89. How to re-compile the kernel?
1) Go to the Linux source code Directory: CD/usr/src/Linux
2) Execute "make config", "Make menuconfig", and "make xconfig" to configure the kernel options, select the desired module, and remove the unwanted module;
3) execute the "make zimage" command. after about 30 to 90 minutes, a new zimage kernel image file will be generated, stored in the/usr/src/Linux/ARCH/i386/boot directory;
4) copy it to the/boot directory;
5) modify the Lilo. conf file and add:

Image =/boot/zimage
Label = newlinux
Root =/dev/hda1 (based on the original file)
Run/sbin/lilo to make the modification take effect.
6) Restart. Enter newlinux to start the new kernel during Lilo.
90. What is a dynamic kernel module?
The dynamic kernel module is a successful design of Linux, which makes Linux more flexible and easy to customize. In fact, the dynamic kernel module is a kernel module, which can not re-compile the kernel, dynamically add some functions to the kernel using the "insmod Module name" command, and use the "rmmod Module name" command to remove them from the kernel.

6. Cheap network solution-Linux: 9

91. How to set up a web server in Linux?
Apache server is the first choice for setting up Web servers in Linux. You can choose to install it when installing Linux. If Apache is not installed at the time of installation, you can find the file: apache-1.3.12.i386.rpm from the CD or on the Apache website, and then execute the following command to complete the installation:
1) rpm-IVH apache-1.3.12.i386.rpm
2) modify the configuration files httpd. conf and access. conf in the/etc/httpd/conf directory;
3) Put the home page file in the/home/httpd/html directory;
4) Run "/etc/rc. d/init. d/httpd start" to start the Apache server.
If you want to disable it, run the/etc/rc. d/init. d/httpd Stop command.
92. How to set up an FTP server in Linux?
In Linux, the most commonly used FTP service software is wu-ftpd, if it is not installed during Linux installation. You can obtain the desired rpmpackage from the disc or website rpmfind.net/linux/rpm/wbyname.html:wu-ftpd-2.6.0-9.i386.rpm. Run the following command to complete the installation:

Rpm-IVH wu-ftpd-2.6.0-9.i386.rpm

Edit the "/etc/inetd. conf" file and point to the new ftpd daemon, as shown below:

Ftp stream tcp Nowait root/usr/sbin/tcpd in. ftpd-L

So far, your Linux can accept the FTP service.
93. How to use Linux to set up a E-MAIL server?
In Linux, the most common E-MAIL server is sendmail, which you can select when installing Linux.
1) make an MX record for the e-mail server on the DNS server;
2) edit the/etc/inetd. conf file and remove the comments about pop and SMTP rows;
3) execute kill-HUP inetd to make the modification take effect;
In this way, users on the e-mail server can send and receive emails through clients such as outlook.
94. How to set up a news server in Linux?
When installing Linux, select the inn package and enable innd when starting the system. During system installation, most of the configuration work has been completed without the need to compile the source code.
1) Configure/etc/news/Inn. conf:

Domain: foo.com
Organization: Foo company news site
Server: localhost
Fill in according to the actual situation;
2) Configure/etc/news/nnrp. access nnrp. access is the nnrpd configuration file used to complete the waiting process of the news readers service. It is used to control access to the site. You do not need to start innd to modify this file.
3) Add a newsgroup:
You can manually edit the/var/lib/news/active file to add a newsgroup, or use the ctlinnd command to add a newsgroup. To manually modify a newsgroup, run the following command to make it take effect:

Ctlinnd reload active "Modify active"

95. How to set up BBS in Linux?
1) slave;
2) execute tar zxvf pbbs.tar.gz to unbind the file;
3) Go To The PBBs directory and run install;
4) change the default settings as needed.
96. How to make Linux a file server?
In Linux, you can use Samba as the file server. You can select Samba when installing Linux to complete the installation.
1) edit/etc/smb. conf and modify the configuration:

NetBIOS name = Linux
Workgroup = sambaserver
Server String = Samba Server
Hosts allow = 192.168.9. 127.
Securoty = Share
Interfaces = 192.168.9.1/24
Name resolve order = Host DNS bcast
Wins support = No
2) restart the SMB server:/etc/rc. d/init. d/SMB restart
3) edit the hosts file of the client and add the parsing to the Samba server;
4) Finally, you can see it on the network neighbor.
97. How do I set up a proxy server in Linux?
1) Go to http://squid.nlanr.net/squid/download squidproxy server software squid-2.2.stable3-src.tar.gz;
2) execute tar xzxf squid-2.2.STABLE3-src.tar.gz
3) Execute./configure
4) execute make and make install to the/usr/local/squid directory;
5) edit the/usr/local/squid. conf file and add:

ACL allowed_hosts SRC 192.168.9.0/255.255.255.0
Note: assume that your intranet IP address is 192.168.9.0;
6) execute/usr/local/squid/bin/squid-Z for initialization
7) run/usr/local/squid/bin/squid to enable the Service.
8) You can access the Internet by setting the Proxy Server IP address and port 3128 on the client.
98. How to set up a transparent gateway in Linux?
Confirm that the Linux kernel supports ipchain, and then write a script ipchains. rule with the following content:
Note: assume that the Internet address of the transparent gateway server is 1.2.3.4, which is already connected to the Internet; the Intranet address is 192.168.9.1, which is connected to the Intranet.

#! /Bin/sh
/Sbin/ipchains-F forward
/Sbin/ipchains-F Input
/Sbin/ipchains-F output
/Sbin/ipchains-P forward deny
/Sbin/ipchains-P input accept
/Sbin/ipchains-P output accept
External_interface = 1.2.3.4
/Sbin/ipchains-A input-J accept-I lo
/Sbin/ipchains-A output-J accept-I lo
/Sbin/ipchains-A input-J deny-I eth1-s 192.168.9.0/24
/Sbin/ipchains-A input-J deny-I eth1-D 192.168.9.0/24
/Sbin/ipchains-A output-J deny-I eth1-s 192.168.9.0/24
/Sbin/ipchains-A output-J deny-I eth1-D 192.168.9.0/24
/Sbin/ipchains-A input-J deny-I eth1-S $ external_interface/32
/Sbin/ipchains-A input-J deny-I eth1-S $ external_interface/32
/Sbin/ipchains-A output-J deny-I eth1-d $ external_interface/32
/Sbin/ipchains-a forward-J accept-I eth0-s 192.168.9.0/24
-D 192.168.9.0/24
/Sbin/modprobe ip_masq_ftp
/Sbin/modprobe ip_masq_quake
/Sbin/modprobe ip_masq_irc
/Sbin/modprobe ip_masq_user
/Sbin/modprobe ip_masq_raudio
/Sbin/ipchains-a forward-J masq-I eth1-s 192.168.9.0/24

After running this script, all machines in the 192.168.9.0 network can connect to the Internet by setting the gateway to 192.168.9.1.
99. What server can Linux build?
Linux can also become a Domain Name Server, PPP server, CVS server, router, and firewall, and also build a server cluster system through the LVS solution. Because the length is limited here, it is just a few minutes. If you are interested, you can refer to professional Linux books.