linux journey

command line

shell

• let’s start with a siple command, echo. The command just prints out the arguments to the display.

  echo hello,world!

  pwd (print working directory)

  pwd

  cd (change directory)

  cd /etc/test
  cd test2

• . ( current directory)
• .. (parent directory)
• ~ (home directory)
• - (previous directory)

ls (list directories)

ls 
ls /home
ls -a   show all of the files include the files which are hidden.
ls -l   l means long, this command will show the files with their detile.
ls -la  show all the files with their detile.
ls -R   recursively list directory contents.
ls -r   reverse order while sorting.
ls -t   sort by modification time, newest first.

touch (create a filw)

• touch allows you to create new empty files.

  touch myfile

• touch is also used to change timestamps on existing files and directories.

  touch myfile
  touch mydirectory

file (show the type of the file’s contents)

file myfile

cat (show the content of files)

cat file1 file2

less (show less of a file)

• if you are viewing text files larger than a simple output.(which means it is too big to view on your screen.) you can use less to open it, that can make it easy to view the file.

  wget linuxqq_2.0.0-b2-1089_x86_64.sh
  mv linuxqq_2.0.0-b2-1089_x86_64.sh qq
  less qq

• the text is displayed in a paged manner, so you can navigate through a text file page by page.

  q quit out of less and back to your shell
  Page up, Page down, up and down Navigate.
  g move to the beginning of the text file
  G move to the end of the file
  h help
  /search search the content behind /

less qq
/qq

history

history   show commands you have typed
ctrl-R 	  
clear 	  clear the screen

cp (copy)

cp myfile /home/files
cp *.jpg /home/jpgs
cp -r directoryone/ /home/document   copy the directory
cp -i my file /home/files   prompt you before overwriting a same-name-file.

mv (move)

• rename file or directory

  mv a b
  mv directory1 directory2

• move files and directories to somewhere

  mv a b directory1 directory2 /home

• wanna a prompt

  mv -i directory1 directory2

• make a backup of the file which is going to be overwritten.

  mv b a
  the previous file a will be back up and renamed as ~a

  mkdir (make a directory)

  mkdir one two

• wanna to create subdirectories?

  mkdir -p one/one two/tow

  rm (remove)

• delete a file. the file being deleted will not been pushing into a trash can, so be careful about rm.

  rm filea

• force to delete

  rm -f filea

• wanna a prompt

  rm -i filea

• delete directories

  rm -r directory 
  or 
  rmdir directory

  find

  find /home -name qq

• find a directory

  find /home -type d -name mydirectory

  help

  help echo
  echo --help

  man

  man ls

  whatis (briefly describe a file)

  whatis cat

  alias

• set a alias for a command. the alias are saved in ~/.bashrc

  alias foobar='ls la'

• unlias

  unalias foobar

  exit

• exit the shell

  exit
  or 
  logout

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