1dial(3NSL) Networking Services Library Functions dial(3NSL)
2
6 dial, undial - establish an outgoing terminal line connection
7
9 cc [ flag... ] file... -lnsl [ library... ]
10 #include <dial.h>
11 int dial(CALL call);
13 void undial(int fd);
16
19 The dial() function returns a file-descriptor for a terminal line open
20 for read/write. The argument to dial() is a CALL structure (defined in
21 the header <dial.h>).
22 When finished with the terminal line, the calling program must invoke
25 undial() to release the semaphore that has been set during the alloca‐
26 tion of the terminal device.
27 CALL is defined in the header <dial.h> and has the following members:
30 struct termio *attr; /* pointer to termio attribute struct */
32 int baud; /* transmission data rate */
33 int speed; /* 212A modem: low=300, high=1200 */
34 char *line; /* device name for out-going line */
35 char *telno; /* pointer to tel-no digits string */
36 int modem; /* specify modem control for direct lines */
37 char *device; /* unused */
38 int dev_len; /* unused */
39 The CALL element speed is intended only for use with an outgoing dialed
43 call, in which case its value should be the desired transmission baud
44 rate. The CALL element baud is no longer used.
45 If the desired terminal line is a direct line, a string pointer to its
48 device-name should be placed in the line element in the CALL structure.
49 Legal values for such terminal device names are kept in the Devices
50 file. In this case, the value of the baud element should be set to -1.
51 This value will cause dial to determine the correct value from the
52 <Devices> file.
53 The telno element is for a pointer to a character string representing
56 the telephone number to be dialed. Such numbers may consist only of
57 these characters:
58 0-9 dial 0-9
63 * dail *
64 # dail #
65 ──────────────────────────────wait for secondary dial tone
66 - delay for approximately 4 seconds
68 The CALL element modem is used to specify modem control for direct
72 lines. This element should be non-zero if modem control is required.
73 The CALL element attr is a pointer to a termio structure, as defined in
74 the header <termio.h>. A NULL value for this pointer element may be
75 passed to the dial function, but if such a structure is included, the
76 elements specified in it will be set for the outgoing terminal line
77 before the connection is established. This setting is often important
78 for certain attributes such as parity and baud-rate.
79 The CALL elements device and dev_len are no longer used. They are
82 retained in the CALL structure for compatibility reasons.
83
85 On failure, a negative value indicating the reason for the failure will
86 be returned. Mnemonics for these negative indices as listed here are
87 defined in the header <dial.h>.
88 INTRPT −1 /* interrupt occurred */
90 D_HUNG −2 /* dialer hung (no return from write) */
91 NO_ANS −3 /* no answer within 10 seconds */
92 ILL_BD −4 /* illegal baud-rate */
93 A_PROB −5 /* acu problem (open() failure) */
94 L_PROB −6 /* line problem (open() failure) */
95 NO_Ldv −7 /* can't open Devices file */
96 DV_NT_A −8 /* requested device not available */
97 DV_NT_K −9 /* requested device not known */
98 NO_BD_A −10 /* no device available at requested baud */
99 NO_BD_K −11 /* no device known at requested baud */
100 DV_NT_E −12 /* requested speed does not match */
101 BAD_SYS −13 /* system not in Systems file*/
102
105 /etc/uucp/Devices
106 /etc/uucp/Systems
111 /var/spool/uucp/LCK..tty-device
116
121 See attributes(5) for descriptions of the following attributes:
122 ┌─────────────────────────────┬─────────────────────────────┐
127 │ ATTRIBUTE TYPE │ ATTRIBUTE VALUE │
128 ├─────────────────────────────┼─────────────────────────────┤
129 │MT-Level │Unsafe │
130 └─────────────────────────────┴─────────────────────────────┘
131
133 uucp(1C), alarm(2), read(2), write(2), attributes(5), termio(7I)
134
136 Including the header <dial.h> automatically includes the header
137 <termio.h>. An alarm(2) system call for 3600 seconds is made (and
138 caught) within the dial module for the purpose of ``touching'' the
139 LCK.. file and constitutes the device allocation semaphore for the ter‐
140 minal device. Otherwise, uucp(1C) may simply delete the LCK.. entry on
141 its 90-minute clean-up rounds. The alarm may go off while the user pro‐
142 gram is in a read(2) or write(2) function, causing an apparent error
143 return. If the user program expects to be around for an hour or more,
144 error returns from read()s should be checked for (errno==EINTR), and
145 the read() possibly reissued.
146 This interface is unsafe in multithreaded applications. Unsafe inter‐
149 faces should be called only from the main thread.
150SunOS 5.11 30 Dec 1996 dial(3NSL)