This reverts commit c3116b2b56.
On second thought, this is less appropriate when using the configuration
file. We may want to define the log filename in config file but not
necessarily enable log feature.
Replace flushing/writing of log at every log write operation with line
buffering, meaning log will be written line by line to make it more I/O
friendly but still update frequently.
Using fsync() on filedescriptors for serial ports can not be relied on.
Add use of tcdrain() to make sure data has been written by the serial
port before proceeding.
This fixes a problem with tio sometimes not writing piped input data to
the serial port before exiting which results in the pending writes being
cancelled / flushed.
When piping to tio it will automatically enter "non-interactive" mode
which means it will not react to any input key sequences but simple read
the input stream and write it to the tty device.
This also means that ctrl-t q can not be used to quit and so tio would
hang forever when used in non-interactive mode.
This change allows to send the standard termination signal by pressing
ctrl-c on tio in non-interactive mode to make it quit.
Replace existing toggle and pulse key commands with the following
generalized key commands which allows to toggle or pulse all serial port
lines:
ctrl-t g Toggle serial port line
ctrl-t p Pulse serial port line
When used, user will be asked which serial line to toggle or pulse.
Also introduce --line-pulse-duration option for setting specific pulse
duration in milliseconds for each serial line using a key value pair
format. Each key represents a serial line. The following keys are
available: DTR, RTS, CTS, DSR, DCD, RI.
Example:
$ tio /dev/ttyUSB0 --line-pulse-duration DTR=200,RTS=300,RI=50
Likewise, the pulse duration can also be set via configuration file
using the line-pulse-duration variable:
line-pulse-duration = DTR=200,RTS=300,RI=50
