mk90.commands

Command cat

Write file bytes to standard output.

Synopsis

cat file

Ordinary invocation: foreground child, PID 3; the shell waits. Allowed as a pipe producer. Also supported as a bare pipe consumer in PID 1 or 2.

Parameters

Parameter	Meaning
`file`	Regular MKS2 file, /dev/null, or /dev/console in the standalone form.

Description

Streams regular files in 256-byte blocks and yields between blocks. Output goes to the LCD console, or to the pipe when CAT is the producer. CAT does not implement a pager; use LESS for reading long text.

cat /dev/null produces immediate end-of-file. Standalone cat /dev/console echoes keyboard input until SU, then D; BK is converted to a newline.

On the right of a pipe, bare cat is a separate consumer process reading the FIFO; it takes no file argument. File checksums are validated on reaching EOF, so earlier data may already have been displayed before an error is discovered.

Examples

cat /mnt/smp1/demo.bas
cat /mnt/smp1/demo.bas | less
cat /dev/null
cat /dev/console

Limits and side effects

One file per invocation; no concatenation of multiple filenames. A console source is not allowed in a pipe. Control bytes are interpreted by the console, not displayed as a hex dump.

Status and diagnostics

Success is status 0. Relevant status codes: 1, 3, 4, 6, 8, 9, 14, 15, 18, 21. See the diagnostic reference.