at commands

[tecknophreak]

how can i through at commands at the modem from c/c++?

[Stuka]

Write the data to the serial port (/dev/ttyS?) that the modem is attached to. Should work.

[Strike]

The man page for termios(3) has a bunch of the ways to set the attributes of the device (handled as a file descriptor returned by open(2) on the device). Then once that is all done, it's a matter of just using read(2) and write(2) to send data on the device.