cat:tldr:4b4b4

The cat -v -t -e command is used to display the contents of a file with certain special characters and control characters visible.

Here is a breakdown of the different options used in the command:

• cat: It is a command-line utility in Unix-like systems used to concatenate and display the contents of files.
• -v: This option makes non-printing characters visible. It escapes non-printing characters with "^" and displays them in a visible form.
• -t: This option displays tabs as ^I and tab characters are aligned with the nearest 8 spaces.
• -e: This option displays the end of each line with a $ symbol.

${filename}: It is the placeholder for the actual filename. You need to replace ${filename} with the name of the file you want to display.

So when you execute the command cat -v -t -e ${filename}, it will display the contents of the file ${filename}. Non-printing characters will be escaped and displayed with ^, tabs will be shown as ^I, and each line's end will be marked with $.