cat command in Linux/Unix

Linux cat command.

cat command is used to display the content of text files and to combine several files to one file.

The cat command does not accept directories.

$ cat [options] file1 [file2...]

cat command main options:

option	description
cat -b	add line numbers to non blank lines
cat -n	add line numbers to all lines
cat -s	squeeze blank lines to one line
cat -E	show $ at the end of line
cat -T	show ^I instead of tabs

View text file data:

$ cat list1.txt
milk
bread
apples

$ cat list2.txt
house
car

$

Combine 2 text files:

$ cat list1.txt list2.txt
milk
bread
apples

house
car

$

Combine 2 text files to another file:

$ cat list1.txt list2.txt > todo.txt
$