• bat - a more advanced cat, such as with syntax highlighting.

Show file contents

$ cat file.txt
Hello, World!

Equivalent to:

$ < file.txt
Hello, World!

Send file contents to another command

$ cat file.txt | my-cmd

Equivalent to:

$ my-cmd < file.txt

Combine files

$ cat file1 file2

$ cat file1 file2 > file3

More interactive mode and the name of each file at the top, use less rather:

$ less file.txt file-2.txt

Help

Man page

Linux:

  • cat on Linux Die.

From macOS:

NAME
     cat -- concatenate and print files

SYNOPSIS
     cat [-benstuv] [file ...]

DESCRIPTION
     The cat utility reads files sequentially, writing them to the standard output.  The file operands
     are processed in command-line order.  If file is a single dash (`-') or absent, cat reads from the
     standard input.  If file is a UNIX domain socket, cat connects to it and then reads it until EOF.
     This complements the UNIX domain binding capability available in inetd(8).
...

Flags

Numbering:

     -b      Number the non-blank output lines, starting at 1.
     -n      Number the output lines, starting at 1.
     -e      Display non-printing characters (see the -v option), and display a dollar sign (`$') at the
             end of each line.

Characters

     -t      Display non-printing characters (see the -v option), and display tab characters as `^I'.
     -v      Display non-printing characters so they are visible.  Control characters print as `^X' for
             control-X; the delete character (octal 0177) prints as `^?'.  Non-ASCII characters (with
             the high bit set) are printed as `M-' (for meta) followed by the character for the low 7
             bits.