Frequently Used commands in fedora linux (1)

Frequently Used commands in fedora linux (1) 1. Common shells in fedora and common shell operations on shell include bash, csh, tcsh, and ksh operations: exit (from one shell to another), exec (from one shell to another) 2. sleep time sleep 5 meaning: sleep 5 seconds 3. Common directory \: root directory ~: Main directory.: Current directory ..: upper-level directory 4. telnet ip address such as: telnet 127.0.0.1 meaning: remotely connect 127.0.0.1 this ip address to exit: logout 5, man command meaning: view command usage 6. date + % F % T % A display year month day date time setting time 7. id user name view User uid, gid 8, ls [-l |- R |-r |-t |-a |-A |-F] [directory 1] [directory 2] l: long format R: show all directory trees starting from the current year r: reverse display t: sort by time a: show all content (including hidden files): show all content (not including. and ..) 9. ln soft link: ln-s file name Link name Hard link: ln file name link 10. chmod is mainly used to modify permissions, for example, chmod u-r, g + w, o = rwx njupt meaning: remove the permissions in the njupt file from r, add w permissions for members of the same group, and set the permissions of others to rwx 11 and cat: cat file name meaning: displays the content of the file 12, cal meaning: Display date 13, command> file meaning: write the output generated by the command on the left to overwrite the output to the file on the right 14. Meaning of the command file: output from the file on the left is appended to the file on the right 14. touch format: touch file meaning: Create a new file 15. mkdir format: mkdir folder name meaning: create a new folder 16. rm format 1: rm file name meaning: delete a File Format 2: rm-r folder name meaning: delete a directory tree 17, rmdir format: rmdir folder name meaning: delete a folder 18, two special files/dev/tty Terminal/dev/null Empty files