Linux skills that should be learned today

The Linux skills you should learn today-general Linux technology-Linux technology and application information. The following is a detailed description. Delete all files in the directory, including subdirectories
Rm-rf directory name

Set/delete environment variables in Character Mode
Under bash
Set: export variable name = variable value
Delete: unset variable name
Under csh
Set: setenv variable name variable value
Delete: unsetenv variable name

Unzip
Tar-imo-bunzip2command can decompress the. bz2 File
Tar xvfj example.tar.bz2
Tar xvfz example.tar.gz
Tar xvfz example. tgz
Tar xvf example.tar
Unzip example.zip
Tar-jvxf some. bz is to change zvxf of tar to jvxf.
Zip/tar rh8 has a graphical interface software file-roeller to do this. In addition, you can use unzip *. zip to unzip the file and unrar *. rar to unzip the rarfile. However, unrar is generally not provided by the system and must be downloaded from the Internet.
# Rpm2cpio example. rpm │ cpio-div
# Ar p example. deb data.tar.gz | tar zxf-
Alien provides conversion between compression formats such as. tgz,. rpm,. slp, And. deb:
Http://sourceforge.net/projects/alien
SEx provides decompression interfaces for almost all visible compression formats:
Http://sourceforge.net/projects/sex

Tar compression and decompression usage
Decompress: x
Compression: c
For gz: z
For bz2: j
Used to display: v

Decompress the instance
Gz file: tar xzvf xxx.tar.gz
Bz2 file: tar xjvf xxx.tar.bz2

Compressing an instance
Gz file: tar czvf xxx.tar.gz/path
Bz2 file: tar cjvf xxx.tar.bz2/path

Use dd for iso
Dd if =/dev/cdrom of =/tmp/aaa. iso

Use ssh to copy files
Assume that both A and B have the SSH service.
1. Copy B from A (pushed over)
Scp-rp/path/filename username @ remoteIP:/path
2. copy from B to A (pull)
Scp-rp username @ remoteIP:/path/filename/path
If one of them is not a LINUX system, you can use SecureFX on WINDOWS.

Change the Mixed Mode of eth0
Change the network adapter eth0 to the hybrid mode:
Ifconfig eth0 promisc
Disable the hybrid mode:
Ifconfig eth0-promisc

How to enable ssh to allow only specified users to log on
Method 1: add the/etc/pam. d/sshd File
Auth required pam_listfile.so item = user sense = allow file =/etc/sshusers onerr = fail
Create the sshusers file under/etc, edit the file, add the user name that you are allowed to use the ssh service, and restart the sshd service.
Method 2: pam rules can also be written as deny
Auth required pam_listfile.so item = user sense = deny file =/etc/sshusers onerr = succeed
Method 3: Set AllowUsers in sshd_config. The format is as follows:
AllowUsers a B c
To restart the sshd service, only a/B/c3 users can log on.