File Handling Utilities

File Handling Commands of Linux

  • mkdir
      Description:
      To create a new empty directory or directories.
      Syntax:
      $ mkdir <option(s)>dir_name(s)
      Example:
       $ mkdir Sam

  • rmdir
      Description:
      To remove an existing directory or directories from the directory hierarchy.
      Syntax:
      $ rmdir <option(s)>dir_name(s)
      Example:
      $ rmdir Sam

  • cat
        Description:
        This command is used to display the contents of the existing file(s), to  create a new file or to          add the data to the end of the existing file.
      Syntax:
        $ cat <option(s)>file_name(s)
      Example:
       $ cat sam.txt 
        Output:
       This command without any options will display the content of the file named  "sam.txt".
       Options: 
      There are three versions of this Command.They are:

      1.$ cat filename(s)
         Desc: This will display the content of the given file(s).
         Ex: $ cat sam.txt

      2.$ cat >filename
          Desc: This will create a new file with the given filename. This will wait for the input after                         giving the input from the the standard keyboard, you have to press  ctrl+d to terminate                    the input.
           Ex: $ cat >sam.txt

      3.$ cat >>filename
         Desc: This will add the lines at the end of the existing file.
         Ex: $ cat >>sam.txt

         i)-n option:
            Desc: This will give the line numbers to the content of the file.
            Ex: $ cat -n sam.txt
        ii)-b option:
           Desc: This will give the line numbers to the content of the file but ignore  the blank lines.
           Ex: $ cat -b sam.txt    


  • mv
    Description:
  This command is used to rename the files with the new file name.Here this  command first creates    an empty file with the name given, then copies the contents of the old file to the new empty file      and finally it deletes the old file.

     Syntax:
     $ mv <option(s)> old_filename new_filename
     Example:
     $ mv sam.txt isad.c
     Output:
     This command will change the name of the "sam.txt" to "isad.c". 


  • rm
   Description:
   This command is used to remove the existing file(s) from directory hierarchy.
   Syntax: 
   $ rm <option(s)> file_name(s)
   Example: 
   $ rm sam.txt
  Output:
  This command will delete the file "sam.txt" from the hierarchy.

   Options:
   1. -f (Forcibly Removal):
      Desc: This option is used to remove the file even though it is write protected.
       Ex: rm -f sam.txt

   2. -r (Recursive Removal):
      Desc: This option will remove all the files and empty directories even though if the directory is                   having the files, it will removes the files first then remove the emptied directory.
        Ex: rm -r sam.txt

  3. -i (Interactive Removal):

     Desc: The rm command with -i flag will ask the user before removing the file or directory.
       Ex: rm -i sam.txt


 

      

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