Linux commands 20180819

2. Mount, Mount USB stick, mount-t Vfat/dev/sdb1/media/disk
4. Umount, uninstall, umount/home/rich/mnt
6. DF to see the size of disk space, Df-h can convert size to m,g form
8. Du, disk space is gone, showing disk usage for a particular directory
   1. DU-C: Total size of all listed files
   2. Du-h: In easy-to-read format
   3. Du-s: Total for each output parameter
10. Sort order, if required to output according to the number size, then add sort-n file1
12. grep, Sed,awk
14. bZIP, TAR, gzip:
    1. gzip file: Compress files to generate. gz files
    2. Gzcat file: Viewing compressed files
    3. Gunzip file.gz: Extracting Files
    4. Tar: Archive data, TAR-CVF Test.tar test/test2/create test.tar files containing test and test2; TAR-TF Test.tar Lists the contents of the tar file; tar-xvf test.tar extracts content from tar.
    5. Encountered many for. Tgz, TAR-ZXVF file.tgz; If you create it, you can use TAR-ZCVF file.tgz file
16. Alias, alias, easy to use, alias li= "Ls-li" equal sign cannot have spaces on either side
18. To view Global environment variables: env or PRINTENV
20. Login shell, the system will be read from the following 5 files:
    1. /etc/profile (System default master boot file)
    2. ~/.bashrc
    3. ~/.bash_profile find BASHRC This file in the home directory, and if so, execute the command in BASHRC.
    4. ~/.bash_login
    5. ~/.profile
22. ETC/PASSWD file (name; group; uid,etc); Etc/shadow is a file that stores passwords
24. Useradd Userdel, passwd Qingli (user who modifies an existing password),
26. chmod u/g/o + r/w/x
28. Yum install Packagename/yum list installed (already installed package)/Yum list Updates/yum update Packagename/yum remove PackageName (delete Package and keep config file)/Yum erase Pakcagename (remove software and all files)
30. Source installation, wget,./configure, make, make install

Linux commands 20180819