Modem Functions

6.2login.c

The functions in login.c implement a login script mechanism that can be used to negotiate through the login: and password: prompts issued by some dial-in servers. The functions are:

•do_script() on page 6-19

•login() on page 6-20

•log_input() on page 6-21

•log_output() on page 6-22

•logserver() on page 6-23.

Modem Functions

6.2.1do_script()

This processes a login script for either login() or logserver().

Syntax

int do_script(char *sfilename)

where:

sfilename is the filename from which to read the script.

Return value

Returns one of the following:

Usage

The do_script() function is an engine to open a text file and treat it as a script for logging into a remote host that has just been dialed into. The script file provides a user-configurable script to login to various hosts. It contains text for strings to output to the modem and text for expected replies from the modem, including timeouts.

Special characters (when at the start of a line) are:

Recognized commands are:

input secs string

gets characters from the modem until the string is matched or secs seconds have elapsed. If the timeout expires before the string is found, the script is aborted.

output string

sends a string to the modem. It can contain escape sequences.

echo text

sends text to the user console (or log).

Modem Functions

6.2.2login()

This function executes a login script to login to a remote host after the connection has been started.

Syntax

void login(void)

Return value

None.

Usage

This is called by the link control code, for example, the dialer, when a link connection has been established. If no login script has been specified, it marks the connection as logged in and returns. Otherwise, it executes the login script.

The login() function sets loggedin to TRUE if the login script was successful (or did not exist), or FALSE if the login attempt failed.

Modem Functions

6.2.3log_input()

This function gets a string from the modem and checks that it matches the passed string.

Syntax

int log_input(char *string, int secs)

where:

string is the sequence to look for.

Return value

Returns one of the following:

TRUE if string was seen within secs seconds.

FALSE if string was not seen within secs seconds.

Usage

The log_input() function waits for up to secs seconds to see if string arrives from the modem. It leaves the input from the modem in modem_in[ ].