cat

Print and concatenate files. More information: https://manned.org/cat.1posix.

• Print the contents of a file to stdout:

cat path/to/file

• Concatenate several files into an output file:

cat path/to/file1 path/to/file2 … > path/to/output_file

• Append several files to an output file:

cat path/to/file1 path/to/file2 … >> path/to/output_file

• Copy the contents of a file into an output file without buffering:

cat -u /dev/tty12 > /dev/tty13

• Write stdin to a file:

cat - > path/to/file