dial(3C)																  dial(3C)

NAME

       dial(), undial() - establish an outgoing terminal line connection

SYNOPSIS

DESCRIPTION

       The  function  returns  a  file	descriptor for a terminal line open for read/write.  The argument to is a structure (defined in the header
       file).

       When finished with the terminal line, the calling program must invoke to release the semaphore that has been set during the  allocation	of
       the terminal device.

       The definition of in the header file is:

       elements are as follows:

	      speed	Intended  only	for use with an outgoing dialed call, in which case its value should be either 300 or 1200 to identify the
			113A modem, or the high- or low-speed setting on the 212A modem.  Note that the 113A modem or the low-speed setting of the
			212A  modem  transmits	at  any rate between 0 and 300 bits per second.  However, the high-speed setting of the 212A modem
			transmits and receives at 1200 bits per second only.

	      baud	Desired transmission baud rate.  For example, one might set baud to 110 and speed to 300 (or 1200).  However, if speed	is
			set to 1200, baud must be set to high(1200).

	      line	If the desired terminal line is a direct line, a string pointer to its device name should be placed in the line element in
			the structure.	Legal values for such terminal device names are kept in the file.  In this case, the  value  of  the  baud
			element need not be specified as it will be determined from the file.

	      telno	A  pointer to a character string representing the telephone number to be dialed.  Such numbers can consist only of symbols
			described below.  The termination symbol is supplied by the function, and should not  be  included  in	the  telno  string
			passed to in the structure.

			Permissible Codes

			Dial

			Dial

			Dial

			4-second delay for second dial tone

			End of number

			Wait for secondary dial tone

			Flash off-hook for 1 second

	      modem	Specifies modem control for direct lines.  Set to non-zero if modem control is required.

	      attr	Pointer  to  a structure, as defined in the header file.  A NULL value for this pointer element can be passed to the func-
			tion, but if such a structure is included, the elements specified in it are set for the outgoing terminal line before  the
			connection is established.  This is often important for certain attributes such as parity and baud rate.

	      device	Holds the device name that establishes the connection.

	      dev_len	Length of the device name that is copied into the array device.

RETURN VALUE

       On  failure,  a	negative value indicating the reason for the failure is returned.  Mnemonics for these negative indices as listed here are
       defined in the header file.

WARNINGS

       Including the header file automatically includes the header file.

       The above routine uses which causes unexpected increases in the size of programs that otherwise do not use standard I/O.

       The function will modify the values of some of the fields of the structure so if is reinvoked, it  will	reinitialize  the  values  of  the
       structure.

FILES

SEE ALSO

       uucp(1), alarm(2), read(2), write(2), thread_safety(5), termio(7).

       UUCP tutorial in

																	  dial(3C)