CAT(1) General Commands Manual CAT(1)

cat — concatenate files

cat [-u] [file...]

cat reads each file in sequence and writes it on the standard output. If no file is given or if file is "-", cat reads from the standard input.

The -u option is ignored, present only for POSIX compatibility.

The cat utility exits 0 on success, and >0 if an error occurs.

‘cat file1 - file2 - file3’
Print the contents of file1; then copy standard input until EOF (^D) is received; then print the contents of file2; then the rest of standard input until EOF (^D) is received again; finally cat will print the contents of file3. Note that when standard input refers to a file, the second dash does nothing as there isn't any remaining data to print.
‘time cat’
Get a stopwatch utility which stops once EOF is pressed.

cat is mostly compliant with the IEEE Std 1003.1-2024 (“POSIX.1”) specification.

Haelwenn (lanodan) Monnier <contact+utils@hacktivis.me>

January 17, 2025 Linux