AT&T UNIX™PC Unix System V Users Manual - tenox

DIAL (3C) DIAL(3C)
NAME
dial - establish an out-going terminal line connection
SYNOPSIS
#include < dial.h >
int dial (call)
CALL call;
void undial (fd)
int fd;
DESCRIPTION
Dial returns a file-descriptor for a terminal line open for
read/write. The argument to dial is a CALL structure (defined in
the < dial.h > header file.
When finished with the terminal line, the calling program must
invoke undial to release the semaphore that has been set during
the allocation of the terminal device.
The CALL typedef in the header file is:
typedef struct {
struct termio *attr; /* pointer to termio * /
/* attribute struct * /
int baud; /* transmission data rate * /
int speed; /* 212A modem: low=300, * /
/* high= 12oo * 1
char *line; /* device name for * /
/* out-going line * /
char *telno; /* pointer to tel-no * /
/* digits string * /
int modem; /* specify modem control * /
/* for direct lines * /
} CALL;
The CALL element speed is 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. The CALL element baud is for the desired transmission
baud rate. For example, one might set baud to 110 and
speed to 300 (or 1200).
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 CALL
structure. Legal values for such terminal device names are kept in
the L-devices file. In this case, the value of the baud element
need not be specified as it will be determined from the L-devices
file.
The telno element is for a pointer to a character string representing
the telephone number to be dialed. Such numbers may consist
only of symbols described in phone(7). The termination symbol
will be supplied by the dial function, and should not be included
in the telno string passed to dial in the CALL structure.
The CALL element modem is used to specify modem control for
direct lines. This element should be non-zero if modem control is
- 1 -