cat file ...
cat
command takes a list of file names for its arguments.$ cat file1 Hello file1
$ cat -n file1 1 Hello 2 3 file1
$ cat file1 file2 file3
enter EOF character ('^D') for each file
):$ cat file1 - file2 - file3
-n |Number the output lines, starting at 1. -b |Number the non-blank output lines, starting at 1. -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.