Shell Basic Command Quick Start - wwangdev/wwangdev.github.io GitHub Wiki

#Shell Basic Command -- Quick Start

Shortcut Key

  • Ctrl+Alt+F1-F6: switch Terminal.
  • Ctrl+Alt+F7: switch to Desktop.
  • tab: auto-completion.
  • tab tab: list all options for completion.
  • Ctrl+u: delete current command line

Need to Know

  • $ -- User, # -- root.
  • Linux is Case Sensitive!
  • /etc/: system/software configuration files.
  • All system commands are files in /usr/bin/.
  • Wildcard:
    • *: any char any length.
    • ?: any char length 1.
    • []: option.
    • [1-9]: option with range.
  • ../: parent directory.
  • ./: current directory.
  • ls -F:
    • blue, ended with /: directory
    • text: black
    • executable, ended with *: green
    • link, ended with @: light blue
  • Run app without terminal hang on: &
  • who: who are logged in.
  • whoami: who is current user.
  • uname: current system info. -a: detailed system info, -r: version info.
  • man: help. J: down, K: up.
  • whatis: function description.
  • apropos: use key word to find function (regex permitted).

File Manipulation

View Directory

  • cd: change directory.
    • /: root directory.
    • ~: user directory.
    • Empty: user directory.
    • .. : parent directory.
  • ls: list files.
    • -a: show hidden files (begun with .)
    • -F: show file types (/,*,@)
    • -l: show property: rwx, links, owner, group, size, last modified date, last modified time, file name
      • -ld: show property of a folder.
    • +directory: list files in the directory
  • pwd: current work directory.
  • vdir: ls -l.

Find Files

  • find: find [Path] -option file.
    • -name: Ex: find /usr/bin/ -name zip
    • -type: b: block, f: file, c: char device, p: pipeline, d:directory, l: link
    • -atime (+/-)n: accessed (more/less than) n days ago
    • -mtime n: modified n days ago
  • locate: locate filename. Use updatedb to update database.
  • whereis: find executable(and source) files. -b: only find executable file. (Could find in /usr/bin or /usr/share/man).

View File

  • cat: display file content, -n: display line number.
  • more: display file content by page, Q to exit.
  • head: -n, first n lines.
  • tail: -n, last n lines.
  • less:
    • space: next page
    • b: previous page
    • /word: search word, / again, search next
    • -M: more details
    • Q: exit
  • grep: search word(use ' ' if space) in a file.
  • egrep: both grep and egrep support regular expression.