MandrakeFAQ (2)

Article title: MandrakeFAQ (2 ). Linux is a technology channel of the IT lab in China. Includes basic categories such as desktop applications, Linux system management, kernel research, embedded systems, and open source.
Q34: how to make your system unresponsive to ping?
A34: prevent your system from responding to ping requests. this is good for network security because no one can ping your server and receive any response. The TCP/IP protocol has many weaknesses. hackers can use some technology to use the channel for transmitting normal data packets to secretly transmit data. Minimizing this risk by making your system unresponsive to ping requests. Run the following command:
　　
Code:
Echo 1>/proc/sys/net/ipv4/icmp_echo_ignore_all
　　
　　
Note that if you want to restore the data, echo 0 .)
　　
　　
Q35: how to start multiple X? what's the best solution?
　　
A35. In fact, you only need to start it on another fake terminal and enter startx --: 2 and so on. For convenience, you can ~ /. Add the following lines to bashrc:
　　
Code:
　　
Alias X = 'startx ---bpp 32-quiet &'
Alias X1 = 'startx --: 1-bpp 32-quiet &'
Alias X2 = 'startx --: 2-bpp 32-quiet &'
Alias X3 = 'startx --: 3-bpp 32-quiet &'
Alias X4 = 'startx --: 4-bpp 32-quiet &'
Alias X5 = 'startx --: 5-bpp 32-quiet &'
　　
　　
Among them, 32 is the color depth of the monitor. you should set it according to your actual situation. Run later # bash
After the change takes effect, run X, X1, X2, X3, X4, and X5 to start six X-Windows. Then you can use Crtl + Atl + Fn to switch your 6 X, Fn = F7, F8,..., F12.
　　
　　
Q36: How do I set permissions for a disk under Mandrake8.1 so that a disk under Windows 98, such as an edisk (a win_e folder under the mnt directory under Mandrake), is visible only to specific users such as root?
A36: mount-t vfat-o umask = 0077/dev/hda7/mnt/win_e
Umask means in contrary to permission settings. So 0077 is meant that owner has full access and group pals and others haven' t any permission.
　　
In addition, Mandrake has mounted ms partitions for you, such as my, cat/etc/fstab.
Code:
/Dev/hdc6/ext3 defaults 1 1
/Dev/hdc7/boot ext3 defaults 1 2
None/dev/pts devpts mode = 0620 0 0
/Dev/hdb/mnt/cdrom auto user, iocharset = gb2312, codepage = 936, noauto, ro, exec 0 0
/Dev/fd0/mnt/floppy auto user, iocharset = gb2312, sync, codepage = 936, noauto, exec 0 0
/Dev/hda1/mnt/win_c vfat iocharset = gb2312, codepage = 936 0 0
/Dev/hda5/mnt/win_d vfat iocharset = gb2312, codepage = 936 0 0
/Dev/hda6/mnt/nt ntfs iocharset = gb2312, ro 0 0
/Dev/hda7/mnt/win_e vfat iocharset = gb2312, codepage = 936 0 0
/Dev/hdc8/mnt/win_c2 vfat iocharset = gb2312, codepage = 936 0 0
/Dev/hdc9/mnt/win_d2 vfat iocharset = gb2312, codepage = 936 0 0
/Dev/hdc10/mnt/win_e2 vfat iocharset = gb2312, codepage = 936 0 0
None/proc defaults 0 0
/Dev/hdc11/usr ext3 defaults 1 2
/Dev/hdc2/var ext3 defaults 1 2
/Dev/hdc5 swap defaults 0 0
　　
　　
Haha, there is more powerful supermount for Mandrake.
　　
Q37: rpm is the most commonly used tool in Mandrake Linux. can you introduce the most basic usage?
A37: Yes, but for more specific usage, you can refer to her Man page. I will only introduce its General Usage example:
　　
Find the Linux kernel version installed in the system:
Code:
Rpm-q kernel
　　
　　
Find the gcc version:
Code:
Rpm-q gcc
　　
　　
Find the list of all installed RPMs
Code:
Rpm-qa | more
　　
　　
You can add grep, for example:
Code:
Rpm-qa | grep kernel
　　
　　
List all configuration files of the software package Linux
　　
Code:
Rpm-qc package name
　　
　　
List all documents:
Code:
Rpm-qd package name
　　
　　
List details
　　
Code:
Rpm-qi package name
　　
　　
List all objects
　　
Code:
Rpm-ql package name
　　
　　
List all file statuses
Code:
Rpm-qs package name
　　
　　
Install the rpm Package
　　
Code:
Rpm-ivh package name
　　
　　
Force installation:
Code:
Rpm-I -- force rpm_source
　　
　　
Delete rpm:
　　
Code:
Rpm-e package name
(You do not need anything after the package name)
　　
Upgrade rpm
Code:
Rpm-U new rpm Package
　　
　　
Verify rpm
　　
Code:
Rpm-V package name
　　
　　
　　
For example, my Mandrake9.0,
Code:
[Root @ huang jboard] # rpm-qa | grep XFree
XFree86-xfs-4.2.1-3mdk
XFree86-4.2.1-3mdk
XFree86-75dpi-fonts-4.2.1-3mdk
XFree86-100dpi-fonts-4.2.1-3mdk
XFree86-devel-4.2.1-3mdk
XFree86-cyrillic-fonts-4.2.1-3mdk
XFree86-server-4.2.1-3mdk
XFree86-libs-4.2.1-3mdk
　　
　　
The following example lists all the packages you have installed and their size (bytes ):
Code:
Rpm-qa | xargs rpm-q -- qf "% {NAME}-% {VERSION} \ t: % {SIZE} \ n
　　
Of course, what's simpler is
Code:
$ Rpm-qa -- qf "% {NAME}-% {VERSION} \ t: % {SIZE} \ n"
　　
　　
　　
Q38: how to prevent the generation of core files?
　　
A38: The core file is used to record the running status information of some programs when a problem occurs. it is of little significance to general users and can be deleted. Add the following in your/etc/profile:
# No core files by default
Code:
Ulimit-S-c 0>/dev/null 2> & 1
　　
Or
Code:
Ulimit-c 0
　　
There will be no core dump files.
　　
If tcsh is used, add a line in. tcshrc as follows:
Code:
Limit coredumpsize 0
　　
　　
　　
Q39: How do I know if the hard disk DMA is enabled for the Mandrake?
　　
A39: hdparm-d/dev/hda # show whether your HD has enabled DMA
Hdparm-c/dev/hda # show whether your HD is using 32-bit I/O
Hdparm-d 1/dev/hda # (which one you want to open, such as HDB)
Hdparm-c 1/dev/hda # enable 32-bit I/O
Hdparm-k 1/dev/hda # Make your configuration take effect
Hdparm-t/dev/had # Check whether your configuration takes effect
If you want to start the above configuration every time you start, you can add the code at the end of the/etc/rc. d/rc. local file:
Hdparm-c 1-d 1-k 1/dev/hda
Everything is done.
(Note: if your hard disk does not support this, please do not try it at will. For more details, please refer to the man page of Mandrake, sometimes it's a great pleasure to talk to Man more)
　　
　　
[Color = red] Q40: What should I do if the KDE desktop icon disappears?
　　
Code:
A40: one common case where KDE fails but does not crash is that the desktop (including wallpaper and desktop icons) disappears and core files are generated in the user directory. in many cases, the user has to quit X and then start again to solve this problem. In fact, you only need to simply run/usr/bin/kdesktop without parameters in terminal (for example, konsole, rxvt, or even cxterm not recommended) to restore the desktop. In addition, the program corresponding to the taskbar is/usr/bin/kicker. If you accidentally use xkill to kill the taskbar, you can run kicker without parameters to retrieve it. In fact, when kde is started, it starts kdesktop first, then kicker, and then gadgets such as ktip and klipper.
　　
　　
Q41: How do I install the flash plug-in for konqueror?
A41: konqueror can be easily loaded. during installation, choose to install it in the mozilla installation directory, and then point the plug-in path to the mozilla plug-in directory in the konqueror plug-in scan path settings, scan again to find the new plug-in, and then re-run konqueror should be able to support flash. haha, my Mandrake90 can only use a stable version of 5.0 plug-in. if you don't know what you can do, you can try it on your own.
　　
Q42: What are common KDE shortcuts?
A42: ctl + tab switch to work desktop
Alt + tab switch application
Alt + f1 open application menu
Alt + f2 open command window
Alt + f3 Open Window menu
Alt + f4 close the window
F1 help
F2 search on the page
F3 search for the next one on the page
Space select/cancel selected file
Ctl + n open the file manager
Ctl + a select all files and directories in the current directory
Ctl + t open a terminal in the current directory
Ctl + w close window
Ctl + f search for files
Ctl + c Copy
Ctl + v paste
Ctrl + Alt + d display desktop
　　
Q43: What are common GNOME shortcuts?
A43: ctl + B bookmarks
Ctl + d copy and paste
Ctl + f search
Shift + ctl + f Web lookup
Ctl + I display property page
Switch ctl + h to home
Ctl + u to the upper level
Ctl + n create a new folder
Ctl + o enabled
Ctl + w close window
Shift + ctl + w close all windows
Ctl + = zoom in
Ctl +-zoom out
Ctl + [return
Ctl +] forward
Ctl + t in the garbage bin
Ctl + r refresh
Ctrl + Alt + d display desktop
　　
Q44: What are some tips for terminal in Mandrake?
A44: Ctrl + s: