OS

Module for basic OS functionality

Const

Unknown*    = 0;

Position*   = 1;

Flag*       = 2;

Parameter*  = 3;

Types

Argument* =
    RECORD
        name*   : String.STRING;
        value*  : String.STRING;
        index*  : LENGTH;
        type*   : LENGTH
    END;

Procedures

ProgramName

Get program name

PROCEDURE ProgramName*(VAR name : String.STRING);

Args

Get number of program arguments

PROCEDURE Args*(): LENGTH;

Arg

Get n-th argument

PROCEDURE Arg*(VAR str : String.STRING; n : LENGTH);

InitArgument

Initialize argument parser.

The parser support a on purpose limited for unambigious parsing. The POSIX type of arguments with space between flag and value is ambigious and therfore not supported.

-f, sets type to Flag and name to f. value is empty.
-fval1, sets type to Parameter, name to f and value to val1

Only alpha numeric characters are supported for short arguments.

–flag, sets type to Flag and name to flag. value is empty.
-flag=val1, sets type to Parameter, name to flag and value to val1

Any character is valid after =. Whitespace is supported by enclosing the value in quotes.

An invalid argument is marked with type set to Unknown and with value set the argument.

Other arguments are returned as type Position and with value set to the argument.

PROCEDURE InitArgument*(VAR arg : Argument);

NextArgument

Fetch next argument or return FALSE if finished

PROCEDURE NextArgument*(VAR arg : Argument): BOOLEAN;

HasEnv

Check if environment variable exists

PROCEDURE HasEnv*(name- : ARRAY OF CHAR): BOOLEAN;

Env

Get environment variable

PROCEDURE Env*(VAR value : String.STRING; name- : ARRAY OF CHAR);

ConsoleReadKey

Read single key from console without echo.

PROCEDURE ConsoleReadKey*(): CHAR;

Execute

Execute cmd without arguments. STDIN, STDOUT & STDERR is redirected to /dev/null. Returns 0 on success.

PROCEDURE Execute*(cmd- : ARRAY OF CHAR): INTEGER;

ExecuteArgs

Execute cmd with arguments. STDIN, STDOUT & STDERR is redirected to /dev/null. Returns 0 on success.

PROCEDURE ExecuteArgs*(cmd- : ARRAY OF CHAR; args- : ARRAY OF Type.STRING): INTEGER;

ExecuteWithCapture

Execute cmd with arguments and capture STDOUT & STDERR. STDIN is redirected to /dev/null. Returns 0 on success.

PROCEDURE ExecuteWithCapture*(cmd- : ARRAY OF CHAR; args- : ARRAY OF Type.STRING; VAR fh : Type.Stream): INTEGER;

GetLastError

Get last error code or OK on no error.

PROCEDURE GetLastError*(VAR error: INTEGER);

Exit

Exit with return code

PROCEDURE Exit*(code : INTEGER);