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LSH(1) Manual Page

NAME

lsh - Lib6502-based SHell

SYNOPSIS

lsh [OPTION]…​ [FILE]

DESCRIPTION

lsh(1) is a simple somewhat unix-alike shell for GeckOS. It reads commands from standard input or from an input file. lsh provides input/output redirection and piping.

OPTIONS

-v

Run with debug output

-d <drive>

Use specified drive as working directory

A - ends the parameter list.

The input file when given is executed instead of standard input.

COMMANDS

The shell has a number of built-in commands:

echo <arguments>

Echo the given arguments to standard output

exit

Exit the shell

cd <newpath>

Use the given new path as new working directory

pwd

Print the current working directory

uname

Print the system information

set <NAME>=<VALUE>

Set an evironment variable to a given value

reset

Reset the computer (reboot)

dup <REDIRECTION>

Replace the input / output / error streams with the ones given for dup

source <FILE>

Execute the contents of the given file

lsenv

Print the list of environment variables

help

Print a short description

ENVIRONMENT VARIABLES

None are used (so far).

INPUT / OUTPUT REDIRECTION AND PIPING

The shell provides input / output redirection for commands that are executed, as well as piping output of one command to the input of another command.

Each command has four streams, of which three can be redirected:

  • standard input - this is where the commands read their input from

  • standard output - here the output is sent to

  • standard error - for error messages

  • console input - input directly from console, e.g. used in more to read key presses.

Only standard input, output and error streams can be redirected. For running a process on a different console, see also the ontty command.

Redirecting input

To send the contents of a specific file to a command to be executed, use the < character followed by the file name to be read as input:

hexdump < file

Redirecting output

To send the output of a command to new file, use the > character, followed by the target file.

hexdump infile > outfile

To append the output of a command to a file use double >>:

hexdump infile >> appendfile

Redirecting error output

To redirect the error output, use the ! character.

hexdump infile ! errfile

Redirecting combined standard and error output

Both the standard output and error streams can be sent to the same output stream. Use a logical combination of the ! and > resp. >> tokens:

hexdump !> stdout_and_err_file
hexdump >>! append_stdout_and_err

Piping

The output of one command can be piped into the input for another command. This can be done using the ' character:

cat file ' hexdump

Note: the character might change in the future.

EXAMPLES

STARTING THE SHELL

lsh -v -d c:

Start the shell in verbose mode, using c: as working directory.

lsh foo.lsh

Start the shell, executing the contents of file foo.lsh.

SHELL COMMANDS

dup ! a:video3

Replace the standard error stream of the current shell with device a:video3.

AUTHOR

Written by André Fachat.

REPORTING BUGS

COPYRIGHT

Copyright 1997, 2020 André Fachat. License GPL2 or later. This is free software: you are free to change and redistribute it. There is no WARRANTY, to the extent permitted by law.

SEE ALSO

ontty