The cat command can be easily associated to the word “concatenation” but it doesn’t have that only function: in fact, cat command gives us the possibility to create files and also to display them.
The name stands for catenate.

Usage

The default cat command syntax is: 
cat [flags] [--] [file1] [file2] [file...]
Where [flags] are the cat flags, read below for more info, [--] indacates that the following parameters won't be considered as flags, while the file parameters indicates the names of one or more files to concatenate. Between the names of two files is possible to use the shell redirection symbol ">", in order to redirect the output to the file considered.

Flags

Here are some of the most common cat flags:
  • -n: Display the line numbers of a file
  • -e: Display "$" at the end of the line and also where there is a gap between paragraphs
  • -T: Display TAB characters