Provided by: libio-termios-perl_0.09-4_all 
NAME
"IO::Termios" - supply termios(3) methods to "IO::Handle" objects
SYNOPSIS
use IO::Termios;
my $term = IO::Termios->open( "/dev/ttyS0", "9600,8,n,1" )
or die "Cannot open ttyS0 - $!";
$term->print( "Hello world\n" ); # Still an IO::Handle
while( <$term> ) {
print "A line from ttyS0: $_";
}
DESCRIPTION
This class extends the generic "IO::Handle" object class by providing methods which access
the system's terminal control termios(3) operations. These methods are primarily of
interest when dealing with TTY devices, including serial ports.
The flag-setting methods will apply to any TTY device, such as a pseudo-tty, and are
useful for controlling such flags as the "ECHO" flag, to disable local echo.
my $stdin = IO::Termios->new( \*STDIN );
$stdin->setflag_echo( 0 );
When dealing with a serial port the line mode method is useful for setting the basic
serial parameters such as baud rate, and the modem line control methods can be used to
access the hardware handshaking lines.
my $ttyS0 = IO::Termios->open( "/dev/ttyS0" );
$ttyS0->set_mode( "19200,8,n,1" );
$ttyS0->set_modem({ dsr => 1, cts => 1 });
Upgrading STDIN/STDOUT/STDERR
If you pass the "-upgrade" option at "import" time, any of STDIN, STDOUT or STDERR that
are found to be TTY wrappers are automatically upgraded into "IO::Termios" instances.
use IO::Termios -upgrade;
STDIN->setflag_echo(0);
Arbitrary Baud Rates on Linux
Linux supports a non-POSIX extension to the usual "termios" interface, which allows
arbitrary baud rates to be set. "IO::Termios" can automatically make use of this ability
if the Linux::Termios2 module is installed. If so, this will be used automatically and
transparently, to allow the "set*baud" methods to set any rate allowed by the
kernel/driver. If not, then only the POSIX-compatible rates may be used.
CONSTRUCTORS
new
$term = IO::Termios->new()
Construct a new "IO::Termios" object around the terminal for the program. This is found
by checking if any of "STDIN", "STDOUT" or "STDERR" are a terminal. The first one that's
found is used. An error occurs if no terminal can be found by this method.
new (handle)
$term = IO::Termios->new( $handle )
Construct a new "IO::Termios" object around the given filehandle.
open
$term = IO::Termios->open( $path, $modestr, $flags )
Open the given path, and return a new "IO::Termios" object around the filehandle. If the
"open" call fails, "undef" is returned.
If $modestr is provided, the constructor will pass it to the "set_mode" method before
returning.
If $flags is provided, it will be passed on to the underlying "sysopen()" call used to
open the filehandle. It should contain a bitwise-or combination of "O_*" flags from the
Fcntl module - for example "O_NOCTTY" or "O_NDELAY". The value "O_RDWR" will be added to
this; the caller does not need to specify it directly. For example:
use Fcntl qw( O_NOCTTY O_NDELAY );
$term = IO::Termios->open( "/dev/ttyS0", O_NOCTTY|O_NDELAY );
$term->setflag_clocal( 1 );
$term->blocking( 1 );
METHODS
getattr
$attrs = $term->getattr
Makes a "tcgetattr()" call on the underlying filehandle, and returns a
"IO::Termios::Attrs" object.
If the "tcgetattr()" call fails, "undef" is returned.
setattr
$term->setattr( $attrs )
Makes a "tcsetattr()" call on the underlying file handle, setting attributes from the
given "IO::Termios::Attrs" object.
If the "tcsetattr()" call fails, "undef" is returned. Otherwise, a true value is returned.
set_mode
get_mode
$term->set_mode( $modestr )
$modestr = $term->get_mode
Accessor for the derived "mode string", which is a comma-joined concatenation of the baud
rate, character size, parity mode, and stop size in a format such as
19200,8,n,1
When setting the mode string, trailing components may be omitted meaning their value will
not be affected.
tiocmget
tiocmset
$bits = $term->tiocmget
$term->tiocmset( $bits )
Accessor for the modem line control bits. Takes or returns a bitmask of values.
tiocmbic
tiocmbis
$term->tiocmbic( $bits )
$term->tiocmbis( $bits )
Bitwise mutator methods for the modem line control bits. "tiocmbic" will clear just the
bits provided and leave the others unchanged; "tiocmbis" will set them.
get_modem
$flags = $term->get_modem
Returns a hash reference containing named flags corresponding to the modem line control
bits. Any bit that is set will yield a key in the returned hash of the same name. The bit
names are
dtr dsr rts cts cd ri
set_modem
$term->set_modem( $flags )
Changes the modem line control bit flags as given by the hash reference. Each bit to be
changed should be represented by a key in the $flags hash of the names given above. False
values will be cleared, true values will be set. Other flags will not be altered.
getmodem_BIT
setmodem_BIT
$set = $term->getmodem_BIT
$term->setmodem_BIT( $set )
Accessor methods for each of the modem line control bits. A set of methods exists for each
of the named modem control bits given above.
FLAG-ACCESSOR METHODS
Theses methods are implemented in terms of the lower level methods, but provide an
interface which is more abstract, and easier to re-implement on other non-POSIX systems.
These should be used in preference to the lower ones.
For efficiency, when getting or setting a large number of flags, it may be more efficient
to call "getattr", then operate on the returned object, before possibly passing it to
"setattr". The returned "IO::Termios::Attrs" object supports the same methods as
documented here.
The following two sections of code are therefore equivalent, though the latter is more
efficient as it only calls "setattr" once.
$term->setbaud( 38400 );
$term->setcsize( 8 );
$term->setparity( 'n' );
$term->setstop( 1 );
my $attrs = $term->getattr;
$attrs->setbaud( 38400 );
$attrs->setcsize( 8 );
$attrs->setparity( 'n' );
$attrs->setstop( 1 );
$term->setattr( $attrs );
However, a convenient shortcut method is provided for the common case of setting the baud
rate, character size, parity and stop size all at the same time. This is "set_mode":
$term->set_mode( "38400,8,n,1" );
getibaud
getobaud
setibaud
setobaud
setbaud
$baud = $term->getibaud
$baud = $term->getobaud
$term->setibaud( $baud )
$term->setobaud( $baud )
$term->setbaud( $baud )
Convenience accessors for the "ispeed" and "ospeed". $baud is an integer directly giving
the line rate, instead of one of the "Bnnn" constants.
getcsize
setcsize
$bits = $term->getcsize
$term->setcsize( $bits )
Convenience accessor for the "CSIZE" bits of "c_cflag". $bits is an integer 5 to 8.
getparity
setparity
$parity = $term->getparity
$term->setparity( $parity )
Convenience accessor for the "PARENB" and "PARODD" bits of "c_cflag". $parity is "n", "o"
or "e".
getstop
setstop
$stop = $term->getstop
$term->setstop( $stop )
Convenience accessor for the "CSTOPB" bit of "c_cflag". $stop is 1 or 2.
cfmakeraw
$term->cfmakeraw
Since version 0.07.
Adjusts several bit flags to put the terminal into a "raw" mode. Input is available a
character at a time, echo is disabled, and all special processing of input and output
characters is disabled.
getflag_FLAG
setflag_FLAG
$mode = $term->getflag_FLAG
$term->setflag_FLAG( $mode )
Accessors for various control flags. The following methods are defined for specific flags:
inlcr
Since version 0.09.
The "INLCR" bit of the "c_iflag". This translates NL to CR on input.
igncr
Since version 0.09.
The "IGNCR" bit of the "c_iflag". This ignores incoming CR characters.
icrnl
Since version 0.09.
The "ICRNL" bit of the "c_iflag". This translates CR to NL on input, unless "IGNCR" is
also set.
ignbrk
Since version 0.09.
The "IGNBRK" bit of the "c_iflag". This controls whether incoming break conditions are
ignored entirely.
brkint
Since version 0.09.
The "BRKINT" bit of the "c_iflag". This controls whether non-ignored incoming break
conditions result in a "SIGINT" signal being delivered to the process. If not, such a
condition reads as a nul byte.
parmrk
Since version 0.09.
The "PARMRK" bit of the "c_iflag". This controls how parity errors and break conditions
are handled.
opost
Since version 0.07.
The "OPOST" bit of the "c_oflag". This enables system-specific post-processing on output.
cread
The "CREAD" bit of the "c_cflag". This enables the receiver.
hupcl
The "HUPCL" bit of the "c_cflag". This lowers the modem control lines after the last
process closes the device.
clocal
The "CLOCAL" bit of the "c_cflag". This controls whether local mode is enabled; which if
set, ignores modem control lines.
icanon
The "ICANON" bit of "c_lflag". This is called "canonical" mode and controls whether the
terminal's line-editing feature will be used to return a whole line (if true), or if
individual bytes from keystrokes will be returned as they are available (if false).
echo
The "ECHO" bit of "c_lflag". This controls whether input characters are echoed back to the
terminal.
setflags
$term->setflags( @flags )
Since version 0.09.
A convenient wrapper to calling multiple flag setting methods in a sequence.
Each flag is specified by name, in lower case, prefixed by either a "+" symbol to enable
it, or "-" to disable. For example:
$term->setflags( "+igncr", "+opost", "+clocal", "-echo" );
TODO
• Adding more getflag_*/setflag_* convenience wrappers
SEE ALSO
• IO::Tty - Import Tty control constants
AUTHOR
Paul Evans <leonerd@leonerd.org.uk>