samarux.man

# SamaruX Manual
#
# (c) 2007-2023 Miguel I. Garcia Lopez, FloppySoftware, Spain
#
# Created:     08 Dec 2014
# Last edited: 27 Dec 2023
#
# $NM is NAME
# $SY is SYNOPSIS
# $DE is DESCRIPTION
# $OP is OPTIONS
# $EX is EXAMPLES
# $NT is NOTES
#
# ========
@alias
#
$NM
alias - Manage command aliases
$SY
alias [name [arg ...]]
$DE
The command alias creates, removes and prints command
aliases.

To create (or modify) an alias, enter the alias name,
the real command name and the arguments (if any).

To remove an alias, simply enter the alias name.

To print all the aliases, enter a command line
without arguments.
$OP
None.
$EX
alias            = Prints all the aliases
alias dir ls     = Creates an alias without arguments
alias lf ls -f   = Creates an alias with arguments
alias lf         = Removes the named alias
$NT
Aliases defined with arguments can't be executed with
pipes (single aliases, can).
# ========
@ascii
#
$NM
ascii - Print the character table
$SY
ascii
$DE
The command ascii prints the character table.
$OP
None.
$EX
ascii
# ========
@batch
#
$NM
batch - Execute commands from a file
$SY
batch file [arg ...]
$DE
The command batch executes commands from a file.

If it's not specified, the default type for the
file name will be ".sx".

When executing, the name of the file becomes
the $0 variable.

If arguments are included, the 1st argument becomes
the $1 variable, the 2nd argument becomes the $2
variable and so on.

The $# variable will have the number of arguments
supplied to batch.
$OP
None.
$EX
batch setmyenv John B01:
batch backup.sx
$NT
Batch commands can be nexted up to 3 levels.
# ========
@builtin
#
$NM
builtin - Print the internal command names
$SY
cmds
$DE
The command builtin prints the available internal
command names.
$OP
None.
$EX
builtin
# ========
@cat
#
$NM
cat - Concatenate files
$SY
cat [-kn] [file ...]
$DE
The command cat writes its input to the standard output.

If no arguments are given, it reads from the standard
input.

The - file means the standard input.
$OP
-k  Skip empty lines
-n  Number lines
$EX
cat
cat -kn phrases.txt
cat -n facts.doc
cat header.txt - footer.txt > myletter.txt
# ========
@cd
#
$NM
cd - Change the current working directory
$SY
cd [directory]
$DE
The command cd changes the current working directory.

If the directory is not supplied as an argument, cd
tries to use the $HOME environment variable.
$OP
None.
$EX
cd A02:
cd 1:
cd
$NT
See the diralias command, for directory names.
# ========
@chmod
#
$NM
chmod - Change file modes (CP/M attributes)
$SY
chmod mode file ...
$DE
The command chmod changes file modes (CP/M attributes).
$OP
Modes are:

+w  To set   write permission  (R/W in CP/M).
-w  To reset write permission  (R/O in CP/M).
+s  To set   system attribute  (SYS in CP/M).
-s  To reset system attribute  (DIR in CP/M).
+a  To set   archive attribute (ARCHIVE ON  in CP/M 3).
-a  To reset archive attribute (ARCHIVE OFF in CP/M 3).

Modes can be combined.

If an attribute is not specified, it will remain unchanged.
$EX
chmod +s login.com
chmod +wa-s notes.txt calendar.doc
# ========
@clear
#
$NM
clear - Clear the console
$SY
clear
$DE
The command clear clears the console.
$OP
None.
$EX
clear
$NT
The command clear searches for the $TERM environment
variable, in order to know how to clear the console.
# ========
@command
#
$NM
Command edition
$SY
Rules to edit command lines
$DE
An usual command line looks like this:

   command arg0 arg1 arg2 ...

To include spaces in an argument, enclose it between
single quotes:

   'This is a single argument'

Environment variables can be used in the command line as
arguments and they will be substituted with their values,
if you precede them with '$':

   echo Your name is $USER

You can include more than a command in the same command
line, by separating them with the ';' character:

   cp letter.old letter.new ; cat letter.new

A command line starting with the '#' character, it is a
comment, with no effect:

   # This is a comment, not a command

You can redirect stdin (console input) with the '<'
character:

   ed < letter.txt

You can redirect stdout (console output) with '>' or
'>>':

   ls *.c > mydir.txt
   echo 'Buy some butler' >> todo.txt

You can redirect the output of a command to the input
of another command (piping), with the character '|':

   ls *.c | more

Or you can enter a combination of above.

You can use the following control characters to edit
the command line:

   - To delete the last character:

     BS / CTRL-H (0x08)
     DEL         (0x7F)

   - To delete the entire line:

     CTRL-U (0x15)
     CTRL-X (0x18)

   - To retype the line:

     CTRL-R (0x12)

   - To execute the line:

     CR / CTRL-M (0x0D)
     LF / CTRL-J (0x0A)

Be aware that in the case of external commands,
if the variable BINDIR exists, SamaruX will
search there the executable files.

If the variable doesn't exists, SamaruX will
search in the current working directory.

To force SamaruX to search in another directory,
prefix the filename with it:

   a04:program

To force SamaruX to search in the current working
directory, prefix the filename with ':':

   :program
$NT
Some commands (alias) have restrictions on above.

Pipes are done using temporary files.
# ========
@compile
#
$NM
How to compile the SamaruX shell and its commands
$SY
This topic explains how to compile the shell with
its builtin commands, and the external commands.
$DE
To compile the shell (and its builtin commands):

  1.Compile with MESCC - in CP/M:
    cc sx
  2.Optimize the code (optional) - in CP/M:
    ccopt sx.zsm
  3.Assemble the ZSM file - in CP/M:
    zsm sx
  4.Build the COM file from the HEX file - in CP/M:
    hextocom sx

Once you have build the shell, you must modify the
file samarux.h, and recompile all the SamaruX external
commands.

To compile an external command (for example: less.c):

  1.Compile with MESCC - in CP/M:
    cc less
  2.Optimize the code (optional) - in CP/M:
    ccopt less.zsm
  3.Build the REL file - in the host OS:
    zmac less.zsm --rel
  4.Build the PRL file - in CP/M:
    link less [OP]
  5.Rename the file from PRL to X - in CP/M:
    ren less.prl less.x
$NT
To build the REL file, I use ZMAC version 03 Dec 2014,
a Z80 cross assembler, downloaded from George Phillips's
site: http://members.shaw.ca/gp2000/zmac.html.

Of course, you can use your preferred tools to achieve
the same results: emulators, hexcom, genprl, etc.

See the source files for more information.
# ========
@cp
#
$NM
cp - Copy files
$SY
cp [-fi] file_src file_dst
cp [-fi] src ... directory
$DE
The command cp copies files.

In the first form, only a single file can be copied.

In the second form, more than a file can be copied (src
can be a single file, an ambiguous file name, or a
directory).
$OP
-f  Force:       Delete destination if already exists
-i  Interactive: Asks to user to delete destination if
                 already exists. It has prevalence
                 over -f option.
-v  Verbose
$EX
cp myfile.txt myfile.bak
cp -i cat.c ls.c head.c b01:
cp 1:*.c 2:*.h 3:
cp -fv a00: b01:
# ========
@cpm
#
$NM
cpm - Execute CP/M commands
$SY
cpm command [arg ...]
$DE
The command cpm executes CP/M commands as PIP, STAT,
ED, BASIC, etc.

Pipes or redirections are useless.

If there are other commands after this in the same command
line, they will not be executed.

The procedure is:

  - Save current environment variables and aliases.
  - Exit from SamaruX to CP/M.
  - Execute the CP/M command.
  - Execute SamaruX quietly.
  - Restore environment variables and aliases.
$OP
None.
$EX
cpm PIP A:=B:*.TXT
cpm BASIC myprog
cpm WS
$NT
In CP/M 2, it uses the $$$.SUB feature of the
standard CP/M CCP.

In CP/M 3, it uses the BDOS function CHAIN TO PROGRAM.

It uses the temporary batch file PROFRST.SX to load and
save the environment variables and aliases.
# ========
@date
#
$NM
date - Print or set the system date and time
$SY
date [[YYYY-MM-DD] hh:mm:ss]
date [[YYYY/MM/DD] hh:mm:ss]
$DE
The command date prints or sets the system date and
time.
$OP
None.
$EX
date
date 17:20:00
date 2015-04-08 17:20:00
$NT
Needs CP/M version 3.
# ========
@df
#
$NM
df - Print free disk space
$SY
df [drive ...]
$DE
The command df prints the free disk space for the
specified drives.
If no drive is specified, it prints the free disk
space for the current drive.
$OP
None.
$EX
df
df A: B:
# ========
@diralias
#
$NM
diralias - Manage directory names
$SY
diralias [name [directory]]
$DE
The command diralias manages the directory names.

A directory name, is an alias for a drive and user
specification.

To create a directory alias, enter the alias name,
followed by the drive and user specification.

To delete a directory alias, simply enter the alias
name.

To print all the directory aliases, enter a command
line without arguments.
$OP
None.
$EX
diralias          = Prints all the directory aliases
diralias root a0: = ROOT: will reference A00:
diralias root     = Removes the directory alias

cd root:
ls root:*.txt
cat root:profile.sx
# ========
@dump
#
$NM
dump - Print files in hexadecimal and ascii
$SY
dump file ...
$DE
The command dump prints files in hexadecimal and
ascii form.
$OP
None.
$EX
dump dump.com
dump login.txt cat.com
# ========
@echo
#
$NM
echo - Print its arguments
$SY
echo [-n] [arg ...]
$DE
The command echo prints its arguments.
$OP
-n  To suppress the new line.
$EX
echo Hello world
echo -n Hello world
# ========
@ed
#
$NM
ed - Edit small text files
$SY
ed [file]
$DE
The command ed edits small text files.

Once in the editor, you can enter the following commands:

edit   line_number   -- Edit an line
insert line_number   -- Insert a line over another
remove line_number   -- Remove (delele) a line
copy   line_number   -- Copy to clipboard
paste  line_number   -- Paste from clipboard
append               -- Append a line
print  [line_number [how_many_lines]]
                     -- Print lines on the console
write  [file_name]   -- Write the file
info                 -- Information
help                 -- Help on commands
exit                 -- Exit to shell
$OP
None.
$EX
ed letter.txt
1 lines read.
ed> print
    0: Hello
ed> append
    1: Bye!
ed> print
    0: Hello
    1: Bye!
ed> insert 1
    1: How are you?
ed> edit 0
    0: Hello my friend.
ed> print
    0: Hello my friend.
    1: How are you?
    2: Bye!
ed> write
ed> exit
# ========
@env
#
$NM
env - Manage environment variables
$SY
env [name [arg ...]]
env [-s] name arg ...
$DE
The command env creates, removes and prints environment
variables.

To create (or modify) an environment variable, enter the
variable name, and the arguments.

To remove an environment variable, simply enter the
variable name.

To print all the environment variables, enter a command
line without arguments.
$OP
-s  To skip spaces
$EX
env                      = Prints all the variables
env TERM vt52            = Creates a variable
env TERM                 = Removes the named variable
env -s NAME John Smith   = Creates NAME as JohnSmith
env -s FILE $HOME phones = Creates FILE as A00:phones
$NT
See the topic 'variables' to find a list of environment
variables used by SamaruX.
# ========
@exit
#
$NM
exit - Quit the shell
$SY
exit
$DE
The command exit quits the shell.
$OP
None.
$EX
exit
# ========
@expr
#
$NM
expr - Compute simple expressions
$SY
expr number1 operator number2
$DE
The command expr computes a simple expression and
outputs the result to the console.

The numbers and the result are 16 bit signed integers,
from -32,768 to +32,767.

Valid operators are:

add -- add two numbers
sub -- subtract two numbers
mul -- multiply two numbers
div -- divide two numbers
mod -- remainder after divide two numbers
$OP
None.
$EX
expr 1 add 3  = Prints 4
expr 5 add -1 = Prints 4
expr 5 sub 1  = Prints 4
# ========
@false
#
$NM
false - Return false
$SY
false
$DE
The command false returns the value false: 1.
$OP
None.
$EX
false
# ========
@fortune
#
$NM
fortune - Print a random adage
$SY
fortune [file]
$DE
The command fortune prints a random epigram of
one line of text.

If no file is specified in the command line, the
source for epigrams will be the file 'fortunes.txt'.
$OP
None.
$EX
fortune
fortune jokes.txt
# ========
@files
#
$NM
File and directory names
$SY
Rules to name files and directories
$DE
SamaruX accepts all usual CP/M file names, including
wildcards (* and ?) with the usual behaviour.

In addition to this, you can specify the directory in
the file name.

A directory can be named with its drive letter and
user number.

Also, you can use the diralias command to name
directories, and use that name instead.

If the drive letter is not included, it's assumed to
be the current drive.(1)

If the user number is not included, it's assumed to
be the current user number.(1)

(1) Be aware that in some circunstances, SamaruX will
    search a file in another directory, instead of the
    current one, if you don't specify it in the
    filename (see the variables BINDIR for external
    executables, and MANPATH for manuals).
    To force SamaruX to search a file in the current
    working directory, prefix the filename with the
    character ':', as in:

    :myprog
    man :mescc stdio
$EX
Legal file and directory names:

a01:file.txt   -- File in drive A, user number 1
2:account.dat  -- File in current drive, user number 2
*.h            -- Files matching *.h in current directory
b2:*.c         -- Files matching *.c in drive A, user
                  number 2
c3:            -- Directory on drive A, user number 3

Using diralias to name directories:

diralias root a0:
ls root:*.x
cd root:

Illegal file and directory names:

a:letter.doc  -- User number not included
c:            -- User number not included
$NT
In some commands, a directory name is equivalent to
all files in that directory (i.e. A2: means A2:*.*).

See the diralias command, to know more about directory
names.
# ========
@goto
#
$NM
goto - Jump to label in batch mode
$SY
goto label
$DE
The command goto jumps to a label in batch mode.

Labels are maximum 8 characteres long, must follow a
comment and must end with a ':' (see example).
$OP
None.
$EX
1: # Entry:
2: echo -n Enter 'y':
3: read REPLY
4: if $REPLY eq y goto Cont
5: goto Entry
6: # Cont:
# ========
@grep
#
$NM
grep - Find text patterns in files
$SY
grep [-options] pattern [file ...]
$DE
The command greps find patterns in files and sends the
result to the standard output.

If no file names are entered, more reads from the
standard input.

The - file means the standard input.
$OP
-c : Count [non] matching lines.
-i : Ignore case.
-v : Select non matching lines instead of matching ones.
$EX
grep -i Elvis bio.txt story.txt article.doc
# ========
@head
#
$NM
head - Print first lines from files
$SY
head [-nNUMBER] [file ...]
$DE
The command head writes the first NUMBER lines from files
to the standard output.

If no arguments are given, it reads from the standard
input.

The - file means the standard input.
$OP
-nNUMBER  Writes up to NUMBER lines (default = 10).
$EX
head -n12 mytasks.txt
head myapp.c
# ========
@history
#
$NM
history - Manage command line history
$SY
history [entry]
$DE
The command history selects an entry from the
command line history or prints all the entries.

To select a history entry, enter the entry
number. The entry number 0 has the last
entered command line.

To print the history entries, enter a command
line without arguments.
$OP
None.
$EX
history 0   = Selects the last command line
history 3   = Selects the entry number 3
history     = Prints all the history entries
# ========
@if
#
$NM
if - Test condition
$SY
if arg1 [not] eq arg2 command
if file [not] exist command
if arg1 [not] in_env command
$DE
The command if tests a condition and runs a command if
the result of the test is true:

eq     -- Test if two strings are equal.
exist  -- Test if a file exists.
in_env -- Test if an environment variable exists.

The optional word not inverts the test result.
$OP
None.
$EX
if TERM not in_env echo Terminal type is unknown!
if $USER eq John batch profjohn
if letter.txt exist ed letter.txt
$NT
The command if it's very useful in batch mode.
# ========
@ls
#
$NM
ls - List files
$SY
ls [-avksfl ...] [dir|file ...]
$DE
The command ls list files.

You can enter ambiguous file names.

If no file name is entered, ls lists all
the files (*.*).
$OP
-a  Print file attributes
-v  Verbose
-k  Print file sizes
-s  Sort file names
-f  Same as -aksv
-l  Same as -aks
$EX
ls a02:
ls -f *.c
ls -sv myfile.c m00:myfile.h myfile.zsm
# ========
@man
#
$NM
man - Print manual pages
$SY
man [[file] topic | ALL | TOPICS]
$DE
The command man prints manual pages about a topic, all
topics, or prints the available topics.

If no file name is given, man searchs in the default
man file "samarux.man".

If no arguments are given, the command is equivalent to:

  man TOPICS

The optional MANPATH environment variable has the man
file path.

If MANPATH does not exists or it's not a valid path,
the current directory will be used instead.

To force man to search in another directory, prefix the
filename with it:

   man a04:mescc stdio

To force man to search in the current working directory,
prefix the filename with ':':

   man :mescc stdio
$OP
None.
$EX
man           -- Print available topics in samarux.man
man cat       -- Print cat topic help in samarux.man
man ALL       -- Print all contents in samarux.man
man wp TOPICS -- Print available topics in wp.man
man wp fi     -- Print fi topic help in wp.man
# ========
@mem
#
$NM
mem - Print memory usage
$SY
mem
$DE
The command mem prints the free and used memory size
in bytes.
$OP
None.
# ========
@more
#
$NM
more - Print the contents of text files
$SY
more [-number] [file ...]
$DE
The command more prints the contents of text files,
doing a pause when the screen is full.

You can enter the number of screen lines or leave
more to take this data from the system.

If no file names are entered, more reads from
the standard input.

The - file means the standard input.
$OP
-number  To specify the number of screen lines
$EX
more
more myfile.doc
more -24 file.txt letter.doc
# ========
@mv
#
$NM
mv - Rename files
$SY
mv old_name new_name
$DE
The command mv rename files.
$OP
None.
$EX
mv schedule.txt schedule.bak
$NT
The command mv can't be used to move files,
or rename directories.
# ========
@profile
#
$NM
Profile
$SY
Profiling the shell
$DE
When running the shell, an optional startup file can be
used to setup your SamaruX environment:

profile.sx : For interactive mode.
profcpm.sx : For CP/M mode.
# ========
@ps
#
$NM
ps - Print running commands
$SY
ps
$DE
The command ps prints the running commands.
$OP
None.
$EX
ps
# ========
@pwd
#
$NM
pwd - Print the current working directory
$SY
pwd
$DE
The command pwd prints the current working
directory.
$OP
None.
$EX
pwd
# ========
@read
#
$NM
read - Read a line from standard input
$SY
read name
$DE
The command read reads a line from standard input and
assign its value to an environment variable.
$OP
None
$EX
echo -n Enter your name:
read USER
echo Hello $USER !!!
# ========
@rm
#
$NM
rm - Remove files
$SY
rm [-fi] dir|file ...
$DE
The command rm remove files.

You can enter ambiguous file names.

If a directory name is entered, rm assumes
all the files in that directory (*.*).

If the file name is ambiguous, rm will
print an error if the option -f is not
entered.
$OP
-f   To force deletion in ambiguous file names
-i   To ask to user for each file deletion
-v   To be verbose
$EX
rm myfile.txt
rm hello.c hello.h
rm -f B01:
rm -fi A02:*.bak
# ========
@samarux
#
$NM
SamaruX - Unix-like shell for CP/M systems

(c) 2007-2023 FloppySoftware, Valencia, Spain
http://www.floppysoftware.es
https://cpm-connections.blogspot.com/
https://github.com/MiguelVis
floppysoftware@gmail.com
$SY
samarux [arg ...]
$DE
SamaruX is a Unix-like shell for Z80 computers, running
the CP/M operating system from Digital Research Inc.

It has been developed with MESCC (Mike's Enhanced Small
C Compiler).
$OP
The optional command line, is a command line for the shell.

If you enter a command line, then SamaruX will execute the
command and return to CP/M (this is known as CP/M mode).

If no command line is given, SamaruX presents the shell
prompt, waiting for user commands (this is known
as interactive mode).

In the interactive mode, enter the exit command to
leave SamaruX and return to CP/M.

In both modes, there is an optional profiling procedure,
to setup your environment, according to your
preferences.

SamaruX has some built-in commands, and since version
2.00, it has some external commands too.
$EX
samarux               -- To enter to the interactive shell
samarux cat file.txt  -- To execute the SamaruX cat
                         command and exit to CP/M
$NT
See the topics in the manual (with man), to learn about
its commands, options, profiling, compiling, etc.
# ========
@shift
#
$NM
shift - Shift positional parameters to the left
$SY
shift
$DE
The shift command shifts the arguments inside a batch
command one position to the left, and decrements $#.

If there are no arguments ($# is 0), nothing happens.
$OP
None.
$EX
batch myscript one two three

  $# = 3, $1 = one, $2 = two, $3 = three

  shift

  $# = 2, $1 = two, $2 = three
# ========
@sleep
#
$NM
sleep - Suspend execution for a specified time
$SY
sleep seconds
$DE
The sleep command suspends the execution for the
specified amount of seconds.
$OP
None.
$EX
sleep 60
$NT
Needs CP/M version 3.
# ========
@sort
#
$NM
sort - Sort text lines
$SY
sort [-rn] [file ...]
$DE
The sort command sorts lines of text and sends
the result to the standard output.

If no file names are entered, sort reads from
the standard input.

The - file means the standard input.
$OP
-r   Reverse the result
-n   Compare numbers instead of text
$EX
grep 2015-05- tasks.txt | sort
sort -n myprog.bas
# ========
@tail
#
$NM
tail - Print last lines from files
$SY
tail [-nNUMBER] [file ...]
$DE
The command tail writes the last NUMBER lines from files
to the standard output.

If no arguments are given, it reads from the standard
input.

The - file means the standard input.
$OP
-nNUMBER  Writes up to NUMBER lines (default = 10).
$EX
tail -n12 mytasks.txt
tail myapp.c
# ========
@tee
#
$NM
tee - Copy standard input to standard output
      and to a file.
$SY
tee file
$DE
The tee command copy the standard input to the
standard output and to a file.
$OP
None.
$EX
cat profile.sx | tee profile.bak
# ========
@terminal
#
$NM
Terminal
$SY
Terminal settings
$DE
The terminal settings can be controlled by following
environment variables:

  $TERM    - Terminal name: vt52, vt100 (or ansi),
             ascii.

  $LINES   - Terminal rows (> 0 and < 256).

  $COLUMNS - Terminal columns (> 0 and < 256).

When a command asks for terminal rows or columns,
the procedure is as follows:

  - If the environment variable exists and has a
    legal value, this value is used.

  - Else, if CP/M is version 3, the values from
    the SCB (System Control Block) are used.

  - Else, the default values are used (25 rows,
    80 columns).
# ========
@true
#
$NM
true - Return true
$SY
true
$DE
The command false returns the value true: 0.
$OP
None.
$EX
true
# ========
@tty
#
$NM
tty - Return terminal name
$SY
tty
$DE
The command tty prints the name of the terminal that is
open as standard input - ie:

  "vt52\n"            (tty returns 0)

If standard input is not a terminal, it prints:

  "not a tty\n"       (tty returns 1)
$OP
None.
$EX
tty
# ========
@type
#
$NM
type - Print information about command type
$SY
type [-abtx] [name ...]
$DE
The command type prints, for each name, how it would be
interpreted if used as a command name.
$OP
-a  Print all matches for each name
-b  Exclude search for builtins
-t  Print a single word instead of a full sentence:
    alias, builtin, file or none
-x  Exclude search for aliases
$EX
type clear
type -t cp mv ls
# ========
@uname
#
$NM
uname - Return system name
$SY
uname [-amnrsv]
$DE
The command uname writes the system name and some of
its characteristics.

If no arguments are given, it writes the system name,
as if the -s option had been specified.
$OP
-a  Write the system name and all its characteristics.
-m  Write the hardware type.
-n  Write the node.
-r  Write the release (full version).
-s  Write the system name.
-v  Write the version (date).
$EX
uname
uname -srv
# ========
@variables
#
$NM
Environment variables
$SY
Environment (& pseudo-environment) variables
$DE
Environment variables can be used in the command line as
arguments and they will be substituted with their values,
if you precede them with '$'.

Pseudo-environment variables are not stored as environment
variables, but they can be used in command lines as if
they were.

Some SamaruX environment variables include:

  $BINDIR  - Directory for SamaruX external commands.

  $HOME    - Default user directory.

  $TERM    - Terminal name.

  $LINES   - Terminal rows.

  $COLUMNS - Terminal columns.

  $USER    - User name.

  $PROMPT  - Prompt string, with some special sequences:

             %$ : $ symbol.
             %u : User name (reads $USER).
             %w : Working directory.
             %% : % symbol.

  $TMPDIR  - Temporary directory.

  $MANPATH - Path for manual file.

SamaruX pseudo-environment variables are:

  $? - Exit code of last executed command (0 for SUCCESS,
       1 for FAILURE).

When executing batch commands, there are some additional
pseudo-environment variables:

  $0        - Batch file name.
  $1 ... $9 - Batch arguments.
  $#        - Number of arguments supplied to batch.
$EX
echo My terminal is $TERM and I am $USER
rm myfile.txt ; echo RM exit code is $?
env PROMPT [%u in %w] %$
$NT
See related topics as batch, profile, terminal, etc.
# ========
@ver
#
$NM
ver - Print SamaruX and CP/M versions and facts
$SY
ver
$DE
The command ver prints the SamaruX and CP/M versions,
the free TPA memory, and some other information.
$OP
None.
$EX
ver
# ========
@wc
#
$NM
wc - Count newlines, words and characters
$SY
wc [file ...]
$DE
The command wc counts the number of newlines, words
and characters in files.

It prints also a line with totals if more than one
file is specified.

If no file names are entered, wc reads from the
standard input.

The - file means the standard input.
$OP
None.
$EX
wc mytasks.txt
grep 2015 diary.doc | wc
$NT
The CR ('\r') characters will not be counted.
# ========
@whoami
#
$NM
whoami - Print the user name
$SY
whoami
$DE
The command whoami prints the user name.
$OP
None.
$EX
whoami