Linux study notes

I. There are 7 running levels in linux. they are: 0halt system shutdown status 1singleusermode single user mode 2multi usermodewhitoutnetwork no network multi-user mode 3multi usermode normal mode 4multi userm...

I. There are 7 running levels in linux:
0 halt system shutdown
1 single user mode
2 multi-user mode whitout network multi-user mode without network
3 multi-user mode normal mode
4 multi-user mode, spare multi-user mode (standby)
5 x DM mode
6 reboot restart mode
How can I view the current running level? You can use the command # runlevel or # who-r
Run-level switch init [0123456]
How to control the default edit level after startup/etc/inittab
Change the id to 0-6. Note: do not change the number of digits 0 or 6.
II. file color meaning in Linux
Blue indicates directory; green indicates executable files; red indicates compressed files; light blue indicates linked files; white indicates other files; yellow indicates device files, including block, char, and fifo.
Red flashes indicate that there is a problem with the linked file; use dircolors-p to see the default color settings, including various colors
And "bold", underline, flashing, and other definitions.
In the console, with ls, you will find that shell displays different types of file projects in different colors, without ls-l
Let's take a rough look at the types of each file. In fact, there is a DIR_COLORS file under/etc. this is
A coloring control template. Copy the template. If you want this configuration to take effect under the root user, copy it to/r.
If you want to take effect under the abc (example) user, copy it to/home/abc. Change the name of the file
Write, and "."). dir_colors use vi to open it. when you look down, you will find a line marked with DIR
On the right side, there are two decimal numbers, and the color of these two characters is different. This is the folder (dir
ECloud. The two numbers are the colors used. The one on the right is the color displayed with ls. Just change one
The color of the number changes. This is the color displayed in the future. There are other
Type of file coloring scheme, the same format, change and try again. And then save the disk. Close the command line window. Open again
The command line shows the modified result. At the top of the DIR_COLORS file, there are modified instructions and different colors
The corresponding number, which can be used as a reference.
Ls command folder color settings:
On the text interface, the Red Hat uses blue as the color of the ls directory and matches it with his black background. it feels too dark to see clearly.
Change to another color:
# Vi/etc/DIR_COLORS
"DIR 01; 34", which is the color of the ls command Directory. 01 indicates bold, and 34 indicates blue.
I changed it to "DIR 01; 37; 44". 37 is in white font, 44 is in blue background, and the visual effect is acceptable.
Then, execute
# Eval 'dircolors/etc/DIR_COLORS'
Note that the 'symbol in the command is keyboard ~ The one under the symbol. do not make a mistake.
Then execute the ls command to check the effect.
The above method is for global modification, if you want to modify only the user
Run the/etc/DIR_COLORS file cp ~ /, And change the name to. dir_colors. then modify the file.
 
 
This article is from the "Rista" blog