2.4.5.4. - RS-232 Serial Interfaces

ser_get(dev_num)

Reads a string of characters, up to and including a newline, from serial device dev_num and returns the string so read. The routine will not return until the read is satisfied. Use ser_get(dev_num, 0) to read up to a newline with a timeout.

ser_get(dev_num, n)

If n is greater than 0, this routine reads n bytes from the serial device dev_num and returns the string so obtained. If n is zero, the routine reads characters up to and including a newline. If the read is not satisfied within two seconds, the routine returns the null string.

ser_get(dev_num, mode)

If mode is the string "byte", reads and returns one unsigned binary byte. The following modes read short or long integers and work the same on both big-endian and little-endian platforms. If mode is the string "int2" reads two binary bytes and returns the short integer so formed. If mode is the string "int4" reads four binary bytes and returns the long integer so formed. By default, the incoming data is treated as big endian. If the incoming data is little endian, use "int2_swap" or "int4_swap". If the device returns less than the required number of bytes, the characters so read are discarded, and ser_get() returns the null string. The tty mode for the device needs to be selected as raw in the config file for this command to work properly.

ser_put(dev_num, string)

Writes the string string to the serial device having device number dev_num, as set in the config file . Returns the number of bytes written.