Creating and Manipulating files

Ways to modify files:

1. touch: creates a zero byte files
2. cp: copies one file to another
3. mv: moves a file from one location to another, even across file systems. Also how to change the name of a file.
4. rm: removes the inode-filename link. The data still exists on the disk drive, however.

Manipulating Files

Examples:

• Vim, Nano, ed, or Emacs

Finding files

The find command can search a directory for matching criteria.

Example:

find . -name *.txt
find /etc -name httpd.conf

Will find all files with names that end with .txt and output their full path to stdout.

Common ‘Find’ Flags

• type
  • f = regular files

    find . -type f -name httpd.conf
    

  • d = directory

    find . -type d -name html
    

  • I = symbolic link

    find . -type l -name redhat-release
    

• user
  • File is owned by user (username or UID)

‘Locate’ command

Relies on a database in /etc/cron.daily/mlocate. Update by running ‘updatedb’.

locate httpd.conf

Reading Text files

• cat
  • This reads the file and outputs all of it to stdout
• less and more
  • Also known as “pagers” these commands will output the contents of a file to the screen, but allow you to navigate through the file as well.
• head and tail
  • These commands let you look at the lines starting at the top or bottom of the file, respectively.

    head -n 100 messages
    tail -n 10 messages
    

    Text Manipulation

• sort
  • Sorts