Telnet

paket "telnet";

The telnet package allows you to create a telnet client.

TelnetClient constructor

Use the TelnetClient constructor to instantiate a TelnetKlijent object, that you will use for all telnet communication.

ƒ TelnetKlijent() : objekat

• takes: no parameters
• returns: TelnetKlijent object
• special cases: none

var klijent = TelnetKlijent();

TelnetKlijent

The TelnetKlijent object has the following properties:

1. uspostaviKonekciju
2. zatvoriKonekciju
3. izlazniTok
4. ulazniTok

uspostaviKonekciju

The uspostaviKonekciju function is used to establish a connection with a Telnet server.

ƒ uspostaviKonekciju(hostname: tekst, port: broj) : void (nedefinisano)

• takes:
  • hostname - hostname of the server you’re connecting to. Use “localhost” if connecting to a local server. (tekst)
  • port - port number (broj)
• returns: nothing
• special cases:
  • Throws exception if connection could not be established

var klijent = TelnetKlijent();

probaj {
    klijent.uspostaviKonekciju("localhost", 23);
}
spasi {
    ispis("Could not connect!");
}

zatvoriKonekciju

The zatvoriKonekciju function is used to end an established connection with a Telnet server.

ƒ zatvoriKonekciju() : void (nedefinisano)

• takes: no parameters
• returns: nothing
• special cases:
  • Throws exception if connection could not be closed

klijent.zatvoriKonekciju();

izlazniTok

The izlazniTok function returns the output stream of a Telnet client.

ƒ izlazniTok() : objekat

• takes: no parameters
• returns: output stream object objekat
• special cases:
  • Throws exception if output stream cannot be provided (no connection has been established or other problems)

var izlaz = klijent.izlazniTok();

ulazniTok

The ulazniTok function returns the input stream of a Telnet client.

ƒ ulazniTok() : objekat

• takes: no parameters
• returns: input stream object objekat
• special cases:
  • Throws exception if output stream cannot be provided (no connection has been established or other problems)

var ulaz = klijent.ulazniTok();

Output Stream object

The output stream object, in simple terms, collects output bytes and sends them to some sink. In the context of Telnet, you will use it for sending messages towards the server.

posaljiBajt

The posaljiBajt function sends a single byte down the output stream.

ƒ posaljiBajt(b: broj) : void (nedefinisano)

• takes: b: byte in number form (broj)
• returns: nothing
• special cases:
  • Throws exception if operation fails

izlaz.posaljiBajt(5);

posalji

The posalji function sends a byte array down the output stream.

ƒ posalji(bytes: BajtNiz) : void (nedefinisano)

• takes: bytes: byte array to send (BajtNiz)
• returns: nothing
• special cases:
  • Throws exception if operation fails

izlaz.posalji("Hello World".bajti());

isprazni

The isprazni function flushes the output stream.

ƒ isprazni() : void (nedefinisano)

• takes: no parameters
• returns: nothing
• special cases:
  • Throws exception if operation fails

izlaz.posalji("Hello".bajti());
izlaz.posalji("World".bajti());

izlaz.isprazni();

Note that you will need to flush the output stream to actually send its contents.

zatvori

The zatvori function closes the output stream.

ƒ zatvori() : void (nedefinisano)

• takes: no parameters
• returns: nothing
• special cases:
  • Throws exception if operation fails

izlaz.zatvori();

pisac

The pisac function returns the buffered writer object for this output stream.

ƒ pisac() : objekat

• takes: no parameters
• returns: buffered writer object (objekat)
• special cases:
  • Throws exception if operation fails

var writer = izlaz.pisac();

Input Stream Object

An Input Stream object is the opposite of an Output Stream object. It collects incoming bytes. In the context of Telnet, you will use it to read messages you get from the server.

zatvoriTok

The zatvoriTok function closes the input stream.

ƒ zatvoriTok() : void (nedefinisano)

• takes: no parameters
• returns: nothing
• special cases:
  • Throws exception if operation fails

izlaz.zatvoriTok();

ucitaj

The ucitaj function reads a given number of bytes from the input stream.

ƒ ucitaj(n: broj) : BajtNiz

• takes:
  • n - number of bytes to read
• returns: array of read bytes (BajtNiz)
• special cases:
  • Throws exception if operation fails

// Reads 1024 bytes
var odgovor = ulaz.ucitaj(1024);
ispis(odgovor.dekodiraj());

ucitajPreostaleBajte

The ucitajPreostaleBajte function reads all remaining bytes from the input stream.

ƒ ucitajPreostaleBajte() : BajtNiz

• takes: no parameters
• returns: array of read bytes (BajtNiz)
• special cases:
  • Throws exception if operation fails

var odgovor = ulaz.ucitajPreostaleBajte(1024);
ispis(odgovor.dekodiraj());

dostupnihBajtova

The dostupnihBajtova function returns an estimated number of bytes that can be read (or skipped over) from this input stream without blocking.

ƒ dostupnihBajtova() : broj

• takes: no parameters
• returns: number of bytes that can be read (broj)
• special cases:
  • Throws exception if operation fails

var available = ulaz.dostupnihBajtova();

preskoci

The preskoci function skips over and discards a specified number of bytes of data from the input stream. It returns the number of bytes actually skiped, since sometimes the number can be lower than the one specified in the arguments.

ƒ preskoci(n: broj) : broj

• takes:
  • n - number of bytes to skip
• returns: actual number of skipped bytes (broj)
• special cases:
  • Throws exception if operation fails

var actuallySkipped = ulaz.preskoci(8);

citac

The citac function returns the buffered reader object for this input stream.

ƒ citac() : objekat

• takes: no parameters
• returns: buffered reader object (objekat)
• special cases:
  • Throws exception if operation fails

var reader = klijent.ulazniTok.citac();