Linux File Commond

• Display the absolutly path of the current directory
  pwd
• Display the contained files and sub directories in the current directory
  ls [option] [filenamePattern]
  Most used options include -a for displaying all files, -l for displaying all the informations for each file,
• Create one/more files
  touch file name or file name pattern
  eg: touch {report,draft}_{AUG,SEP,NOV}{1,2,3}
• Create directory
  mkdir
• Remove directory
  rmdir
• Copy files
  cp
• Move files
  mv
• Link files
  ln -s originalFile linkFile
  ln originalFile linkFile
• Display information, display all the matches of the wildcard pattern, that usefull to avoid operation on wrong files when use echo before use wildcard pattern delete or move files.
  echo [wildcard pattern]
• Change the file permissions
  chmod permission fileName
  Owner                     Group                    Others
  execute write read    execute write read   execute write read
           1      2     4             1      2     4            1      2     4
• Change the file owner
  chown username filename
• Change the file owner group
  chown username:groupName fileName
• Search files
• wildcard * ? ~
• Display file content
  
  • cat filename display the contents of the file
  • less fileName1 [fileName 2 …fileName n] view one or more files at the same time :n(to view next page) :p(to view previous page) to navigate from pages and automaticaly paginates the file.
  • head -number fileName  view the fist number of lines in the file
  • tail -number fileName  view the last number of lines in the file