Linux operating system classic practical skills 33

1: HOST fun: Host can be used to query the domain name, however it can get more information. Host -t mx linux.com can query the MX record of Linux.com and the name of the Host that handles Mail. Host -l linux.com will return all domain names registered under linux.com. Host -a linux.com will display all domain information for this host.

2: Find the files you need for the command. Maybe you want to figure out what other related files and commands are used in a command? Try ldd. For example, ldd traceroute, the result will be libc.so.6, lid-linux.so.2

3: Timing! Timing! Do you want to process it regularly? You definitely want to make it easier for you! crontab can Listen to your instructions. In the command line, type: crontab -e to enter the text editor, and then enter 0 5 * * * wget -t3 -I/home/tom/URLs -N. This will run the wget command every morning at 5 o'clock. The first five are time parameters: time, day, month, day of the week. You can 0 5 * * 6,0 command line here, so it runs every 5am on Saturdays and Sundays. You need man 5 crontab for a more detailed explanation. By the way, wget is a small program that takes web pages. The top of the console shows the current time: Add the environment variable PROMPT_COMMAND to /etc/bashrc or ~/.bashrc. Export PROMPT_COMMAND='echo -ne "33733[2;999r33[1;1H33[00;44m33[K"`date`"33[00m338"'

4: Use up to 23 virtual Terminal (VT), suppose you have 6 now, copy the files in /etc/inittab, add

8:234:respawn:/sbin/getty 38400 tty8

24:234: Respawn:/sbin/getty 38400 tty24

To skip VT7, because X uses this terminal. Then telinit q to reload the configuration file. Use left Alt+Fn to switch between 1-6 and 8-12, and use the right Alt+Fn key to toggle between 13-24.

5: Console switch: Left Alt-direction key, cycle through the console. The effect is the same as Alt+Fn.

6: Simple Dos to Unix: If you have annoying Ctrl-M at the end of each line in your text file, use this command to quickly solve the problem sed 's/^M//' filename > newfilename

7: Quickly create MP3 playlists: find /mnt/cdrom -name *.mp3 -print >> cd1.play.list. This will put all MP3s in CDRom The file creates a file called cd1.play.list. Then use xmms or x11amp to play it.

8: Important information in /proc

cat /proc/cpuinfo - CPU (ie vendor, Mhz, flags like mmx)

cat /proc/interrupts - interrupt

cat /proc/ioports - Device IO Port

cat /proc/meminfo - Memory Information (ie mem used, free, swap size)

cat /proc/partitions - All partitions of all devices

cat /proc/pci - Information about PCI devices

cat /proc/swaps - Information about all Swap partitions

cat /proc/version - Linux version number

9: The real Console interface: To be honest, neither KDE nor GNome I like it. After all, I have been immersed in Windows for so long. But under the Console is actually the real Cool interface. Using SVGATextMode allows your command line interface to reach 132x60 (standard is 80x25). My 486 (Trident9440) uses 132x43, and the dense characters are like Hollywood's movies a few years ago (now even Windows in the movie). It feels mysterious. The configuration file is in /etc/TextConfig, but if your XWindow doesn't display properly, then it's estimated that this won't be used (after all, it was a few years ago).

10: Let your hard drive fly: 32Bit I/O and DMA can also be used under Linux. Open the 32Bit transfer mode with /sbin/hdparm -c1 /dev/hda(hdb,hdc..) and open the DMA with the command /sbin/hdparm -d1 /dev/hda(hdb,hdc...). Finally, use /sbin/hdparm -k1 /dev/hda to keep the hard disk set after reset. As a result, the hard disk read and write speed should be more than doubled.

11: Fine-tuning your Ext2: The command tune2fs under Linux can set the maximum number of Mounts (because Linux immediately in the mounted clean state, after reaching a certain number of mounts, it will force e2fsck to switch like this every day. It is very inconvenient for the machine. For other uses of the tune2fs command, see man.

12: Blinking Tabs in Netscape is prohibited: Modify Netscape*blinkingEnabled: False in ~/.Xdefaults and run xrdb -Load ~/.Xdefaults

13: Change XTerm at any time Font size: shift plus +/-

14: Ext2 file attributes: lsattr lists attributes, and chattr can change attributes. For example, chattr +A filename will not modify its last access time attribute; chattr +i can avoid being rm.

15: SIS6326 graphics card configuration: Add in Device: DacSpeed ​​110 Option "no_bitblt" Option "sw_cursor"

16: Use strings to separate strings from Binary files

17: You are probably used to using Top to observe the system usage, so that you can use Vmstat 1 to see the cpu's idleness (display the last item of the result).

18: Using the Watch command, repeatedly executing specific commands, such as "watch ls -l /tmp/blah", will always observe the file size change.

19: Use pppstats to get ppp connection data.

20: Display NFS for remote machines: showmount -e hostname

21: Use autofs to save you every time mount and umount, and then autofs rpm in RedHat6.0. Once installed, you can enjoy the convenience of automatically loading the file system. In the /misc directory, create a cd directory, if you use its own auto.misc and auto.master, you can implement the automatic loading function.

22: In the Bash Shell, you can use! Repeat the commands you have entered a few times, so you can save the trouble of scrolling up. Use ctl+R to interactively retrieve previously used command lines.

23: Use cd - to switch between the two cd /directory/operations. If cd /home/foo followed by cd /home/maison then cd - will enter /home/foo and then cd - will enter /home/maison.

24: Shortcuts in Bash: ESCAPE-B will forward a word, Ctrl-K will delete all characters from the cursor to the end of the line.

25: Use grep in the PS command, for example: ps auxw |  Grep gpm will list all processes that have gpm characters.

26: Execute multiple commands at the same time on the same command line: separated by semicolons. For example, compile a source file: type ./configure ; make ; make install . Then you can go for a walk (don't spend too much time in front of the computer, there are a lot of good things in life.)

27: Output the results to a file, such as ls -l > foo.file.

28: Use the Top command to monitor system status, memory usage, boot time, process status, usage per user, and more. Use the S command to change the time it is refreshed: a .5 will cause it to be updated every half second.

29: Unzip multiple files at the same time, unzip * is incorrect, but unzip "*".

30: Creating symbolic links is probably the most useful feature, ln -s real-file symbolic-file, whether it's a device, a document, or a script.

31: Change the displayed unit. For example, du -hm will output the result in M, and the same du -hk will output in K.

32: Automatic Logoff, add a sentence in ~/.bashrc: TMOUT=300 will logoff after 5 minutes, but if less programs like this will not start.

33: When using less or more, start the editor directly: typing v in less will start vi or other editor you specified in the environment variable, but more can only use vi .