NAME

Comedi::Lib - Perl API for Comedilib (NEW version)

VERSION

Version 0.24

SYNOPSIS

Comedi::Lib provides a Perl wrapper around the Comedilib library. This supports Perl code controlling and accessing control and measurement devices.

use Comedi::Lib;

# Create a Comedi::Lib object and open the Comedi device
my $cref = Comedi::Lib->new(device => '/dev/comedi0', open_flag => 1);

# Get the driver and board name of the device
my $dname = $cref->get_driver_name();
my $bname = $cref->get_board_name();
...
...
...
# Close the Comedi device (optional)
$cref->close();

DESCRIPTION

This module provides a Perl API for Comedilib. Comedilib is a separately distributed package containing a user-space library that provides a developer-friendly interface to the Comedi devices. This module consists of the functions that the Comedilib library provides.

TODO

I don't use XS, C::Scan or something like that, to export constants and macros to the callers name-space, as long as it's not clarified which constants and macros used for Comedilib and which for 'pure' Comedi (driver development). Both the documentation and the source code couldn't help me at all to resolve that problem.

NOTE

This module does _not_ support any ALPHA constants, macros or functions. This will be done by a separately module, anytime soon.

DEPENDENCIES

Comedi::Lib is dependent on the Comedilib library. Please download and install the latest version at http://www.comedi.org/. The Comedilib library _must_ be found in your library path when using this module. The library is defaultly installed in /usr/local/lib - in this case, be sure that the /usr/local/lib path is in your /etc/ld.so.conf.

Comedi::Lib also depends on the InlineX::C2XS, define and enum modules, as well as the Test::More, POSIX and Carp core modules, and the strict and warnings pragmas.

EXPORT

None, this is an object-oriented Perl module.

USAGE

CONSTANTS

This class provides a set of constants . The constants defined at this time are:

# Comedi's major device number
COMEDI_MAJOR

# Maximum number of minor devices (this can be increased)
COMEDI_NDEVICES

# Number of config options in the config structure
COMEDI_NDEVCONFOPTS

# Length of nth chunk of firmware data
COMEDI_DEVCONF_AUX_DATA3_LENGTH  
COMEDI_DEVCONF_AUX_DATA2_LENGTH  
COMEDI_DEVCONF_AUX_DATA1_LENGTH  
COMEDI_DEVCONF_AUX_DATA0_LENGTH  
COMEDI_DEVCONF_AUX_DATA_HI  
COMEDI_DEVCONF_AUX_DATA_LO 
COMEDI_DEVCONF_AUX_DATA_LENGTH

# Max length of device and driver names
COMEDI_NAMELEN

# Packs and unpacks a channel/range number (see also macro section)
CR_FLAGS_MASK
CR_ALT_FILTER
CR_DITHER
CR_DEGLITCH
CR_ALT_SOURCE
CR_EDGE
CR_INVERT

# Analog ref
AREF_GROUND
AREF_COMMON
AREF_DIFF
AREF_OTHER

# Counters
GPCT_RESET
GPCT_SET_SOURCE
GPCT_SET_GATE
GPCT_SET_DIRECTION
GPCT_SET_OPERATION
GPCT_ARM
GPCT_DISARM
GPCT_GET_INT_CLK_FRQ
GPCT_INT_CLOCK
GPCT_EXT_PIN
GPCT_NO_GATE
GPCT_UP
GPCT_DOWN
GPCT_HWUD
GPCT_SIMPLE_EVENT
GPCT_SINGLE_PERIOD
GPCT_SINGLE_PW
GPCT_CONT_PULSE_OUT
GPCT_SINGLE_PULSE_OUT

# Instructions
INSN_MASK_WRITE
INSN_MASK_READ
INSN_MASK_SPECIAL

INSN_READ
INSN_WRITE
INSN_BITS
INSN_CONFIG
INSN_GTOD
INSN_WAIT
INSN_INTTRIG

# Trigger flags, used in comedi_trig structures
TRIG_BOGUS
TRIG_DITHER
TRIG_DEGLITCH
TRIG_CONFIG
TRIG_WAKE_EOS

# Command flags, used in comedi_cmd structures
CMDF_PRIORITY
TRIG_RT
CMDF_WRITE
TRIG_WRITE
CMDF_RAWDATA

COMEDI_EV_START
COMEDI_EV_SCAN_BEGIN
COMEDI_EV_CONVERT
COMEDI_EV_SCAN_END
COMEDI_EV_STOP
TRIG_ROUND_MASK
TRIG_ROUND_NEAREST
TRIG_ROUND_DOWN
TRIG_ROUND_UP
TRIG_ROUND_UP_NEXT

# Trigger sources
TRIG_ANY
TRIG_INVALID
TRIG_NONE
TRIG_NOW
TRIG_FOLLOW
TRIG_TIME
TRIG_TIMER
TRIG_COUNT
TRIG_EXT
TRIG_INT
TRIG_OTHER

# Subdevice flags
SDF_BUSY
SDF_BUSY_OWNER
SDF_LOCKED
SDF_LOCK_OWNER
SDF_MAXDATA
SDF_FLAGS
SDF_RANGETYPE
SDF_MODE0
SDF_MODE1
SDF_MODE2
SDF_MODE3
SDF_MODE4
SDF_CMD
SDF_SOFT_CALIBRATED
SDF_CMD_WRITE
SDF_CMD_READ
SDF_READABLE
SDF_WRITABLE
SDF_WRITEABLE
SDF_INTERNAL
SDF_RT
SDF_GROUND
SDF_COMMON
SDF_DIFF
SDF_OTHER
SDF_DITHER
SDF_DEGLITCH
SDF_MMAP
SDF_RUNNING
SDF_LSAMPL
SDF_PACKED
SDF_PWM_COUNTER
SDF_PWM_HBRIDGE

# Subdevice types
COMEDI_SUBD_UNUSED
COMEDI_SUBD_AI
COMEDI_SUBD_AO
COMEDI_SUBD_DI
COMEDI_SUBD_DO
COMEDI_SUBD_DIO
COMEDI_SUBD_COUNTER
COMEDI_SUBD_TIMER
COMEDI_SUBD_MEMORY
COMEDI_SUBD_CALIB
COMEDI_SUBD_PROC
COMEDI_SUBD_SERIAL
COMEDI_SUBD_PWM

# Configuration instructions
INSN_CONFIG_DIO_INPUT
INSN_CONFIG_DIO_OUTPUT
INSN_CONFIG_DIO_OPENDRAIN
INSN_CONFIG_ANALOG_TRIG
INSN_CONFIG_ALT_SOURCE
INSN_CONFIG_DIGITAL_TRIG
INSN_CONFIG_BLOCK_SIZE
INSN_CONFIG_TIMER_1
INSN_CONFIG_FILTER
INSN_CONFIG_CHANGE_NOTIFY

COMEDI_INPUT
COMEDI_OUTPUT
COMEDI_OPENDRAIN

COMEDI_UNKNOWN_SUPPORT
COMEDI_SUPPORTED
COMEDI_UNSUPPORTED

# Range stuff (see also macro section)
RF_EXTERNAL

# Units
UNIT_volt
UNIT_mA
UNIT_none

COMEDI_MIN_SPEED

MACROS

This class provides also a set of (pseudo-)macros (implemented as a method). The macros defined at this time are:

# Packs and unpacks a channel/range number
CR_PACK($chan, $rng, $aref)
CR_PACK_FLAGS($chan, $rng, $aref, $flags)

# Intended only for driver development work?
CR_CHAN($a)
CR_RANGE($a)
CR_AREF($a)

# Range stuff   
# Intended only for driver development work?
RANGE_OFFSET($a)
RANGE_LENGTH($a)

# Intended only for driver development work?
RF_UNIT($flags)

Example code,

my $chanspec = $cref->CR_PACK($chan, $rng, $aref);

FUNCTIONS

DESTROY

Close the Comedi device connected to the object.

new

Create a new Comedi::Lib object for accessing the library.

Example code,

my $cref = Comedi::Lib->new(device => '/dev/comedi0', open_flag => 1);

close

Close a Comedi device.

Example code,

my $retval = $cref->close();
  
if ($retval != 0) {
   croak "Couldn't close the Comedi device";
}

If successful, close() returns 0. On failure, -1 is returned.

open

Trigger an explicit open() call to open the Comedi device. If the device is already open, close and reopen it.

You _need_ to be root to open a Comedi device. Comedi::Lib checks that.

Example code,

# Create a new object (don't open the device yet).
my $cref = Comedi::Lib->new(device => "/dev/comedi1", open_flag => 0);
...
...
...
# Now open the Comedi device
$cref->open();

If successful, open() returns defined. On failure, undef is returned.

loglevel

Change Comedilib logging properties.

The default loglevel can be set by using the environment variable COMEDILIB_LOGLEVEL. The default loglevel is 1.

The meaning of the loglevels is as follows:

COMEDI_LOGLEVEL = 0: -- Comedilib prints nothing.
COMEDI_LOGLEVEL = 1: -- Comedilib prints error messages when there is a self-consistency error. (i.e., an internal bug)
COMEDI_LOGLEVEL = 2: -- Comedilib prints an error message when an invalid parameter is passed.
COMEDI_LOGLEVEL = 3: -- Comedilib prints an error message whenever an error is generated in the Comedilib library or in the C library, when called by Comedilib.
COMEDI_LOGLEVEL = 4: -- Comedilib prints a lot of junk.

Example code,

my $previous_loglevel = $cref->loglevel($new_loglevel);
print "Changed loglevel from $previous_loglevel to $new_loglevel\n";

This class method returns the previous loglevel.

Note: Comedilib evaluates the COMEDILIB_LOGLEVEL environment variable during open() is called. The Comedi::Lib implementation of this function allows you to set the above variable once the Comedi device is already opened.

perror

Print a Comedilib error message.

Example code,

unless ($cref->open()) {
   $cref->perror($device);
   croak "Terminating...";
}

The class method perror() prints an error message to stderr. The error message consists of the argument string, a colon, a space, a description of the error condition, and a new line.

strerror

Return string describing Comedilib error code.

Example code,

unless ($cref->open()) {
   my $errnum = $cref->errno();
   my $errmsg = $cref->strerror($errnum);
   croak "An error has occurred - $errmsg";
}

The class method strerror() returns a character string describing the Comedilib error errnum. An unrecognized error number will return a string "undefined error", or similar.

errno

Number of the last Comedilib error. This error number can be converted to a human-readable form by the methods perror() and strerror().

Example code,

# See strerror()

The errno() class method returns an integer describing the most recent Comedilib error. This integer my be used as the errnum argument for strerror().

fileno

Integer descriptor of the Comedi device.

my $fileno = $cref->fileno();
print "File # of Comedi device - $fileno\n";

If successful, fileno() returns a file descriptor, or -1 on error.

get_n_subdevices

Number of subdevices

Example code,

my $n_subdevices = $cref->get_n_subdevices();
print "# of subdevices - $n_subdevices\n";

The class method get_n_subdevices() returns the number of subdevices belonging to the Comedi device previously opened during the Object creation or explicitly by an open() call.

get_version_code

Comedi version code.

Example code,

my @version_code = $cref->get_version_code();
printf("Comedi version code - %d.%d.%d\n", @version_code);

Returns the Comedi kernel module version code, or -1 on error.

get_driver_name

Comedi driver name.

Example code,

my $driver_name = $cref->get_driver_name();
print "Comedi driver name - $driver_name\n";

Returns a character string containing the name of the driver. This class method returns undef if there is an error.

get_board_name

Comedi device name.

Example code,

my $board_name = $cref->get_board_name();
print "Comedi board/device name - $board_name\n";

Returns a character string containing the name of the device. This class method returns undef if there is an error.

get_subdevice_type

Type of subdevice.

Example code,

my $subdev_type = $cref->get_subdevice_type($subdev);

if ($subdev_type == Comedi::Lib::COMEDI_SUBD_AI) {
   print "We've an analog input subdevice\n";
}

This class method returns the subdevice type, or -1 if there is an error.

find_subdevice_by_type

Search for subdevice type.

Example code,

my $idx = $cref->find_sundevice_by_type(Comedi::Lib::COMEDI_SUBD_DO, 0);
croak "No digital output subdevice found\n" if $idx == -1;

print "Found digital output subdevice at index - $idx\n";

If it finds a subdevice with the requested type, find_subdevice_by_type() returns its index. If there is an error, the method returns -1 and sets the appropriate error.

get_read_subdevice

Find streaming input subdevice.

Example code,

my $streaming_input_support = $cref->get_read_subdevice();

if ($streaming_input_support == -1) {
   print "No streaming input support available\n";
}
else {
   print "Comedi subdevice no. $streaming_input_support ",
         "allows streaming input\n";
}

This class method returns the subdevice whose streaming input buffer is accessible through the previous opened device. If there is no such subdevice, -1 is returned.

get_write_subdevice

Find streaming output subdevice.

Example code,

my $streaming_output_support = $cref->get_write_subdevice();

if ($streaming_output_support == -1) {
   print "No streaming output support available\n";
}
else {
   print "Comedi subdevice no. $streaming_output_support ",
         "allows streaming output\n";
}

This class method returns the subdevice whose streaming output buffer is accessible through the previous opened device. If there is no such subdevice, -1 is returned.

get_subdevice_flags

Properties of subdevice.

Example code,

my $subdev_flags = $cref->get_subdevice_flags($subdev);

if ($subdev_flags & Comedi::Lib::SDF_READABLE) {
   print "The subdevice can be read\n";
}
else {
   print "The subdevice can't be read\n";
}

if ($subdev_flags & Comedi::Lib::SDF_WRITEABLE) {
   print "The subdevice can be written\n";
}
else {
   print "The subdevice can't be written\n";
}

This method returns a bitfield describing the capabilities of the specified subdevice. If there is an error, -1 is returned, and the Comedilib error value is set.

get_n_channels

Number of subdevice channels.

Example code,

my $n_channels = $cref->get_n_channels($subdev);
print "Analog input no. of channels - $n_channels\n";

Returns the number of channels of the subdevice with the index subdev. This method returns -1 on error.

range_is_chan_specific

Range information depends on channel.

Example code,

my $retval = $cref->range_is_chan_specific($subdev);
croak "An error has occurred" if $retval == -1;

unless($retval) {
   print "The channels of the subdevice hasn't different ",
         "range information\n";
}
else {
   print "Each channel of the subdevice has different ",
         "range information\n";
}

If each channel of the specified subdevice has different range information, this method returns 1. Otherwise, this method returns 0. If there is an error, -1 is returned.

maxdata_is_chan_specific

Maximum sample depends on channnel.

Example code,

my $retval = $cref->maxdata_is_chan_specific($subdev);
croak "An error has occurred" if $retval == -1;

unless($retval) {
   print "The channels of the subdevice hasn't different ",
         "maximum sample values\n";
}
else {
   print "Each channel of the subdevice has different ",
         "maximum sample values\n";
}

If each channel of the specified subdevice has different maximum sample values, this method returns 1. Otherwise, this method returns 0. If there is an error, -1 is returned.

get_maxdata

Maximum sample of channel.

Example code,

# Read maxdata of analog input channel $chan
my $maxdata = $cref->get_maxdata($subdev, $chan);
croak "An error has occurred" unless $maxdata;

print "Maximum data value for analog input channel $chan - $maxdata\n";

Returns the maximum valid sample value, or 0 on error.

get_n_ranges

Number of ranges of channel.

Example code,

# Read number of ranges for analog input channel $chan
my $n_ranges = $cref->get_n_ranges($subdev, $chan);

if ($n_ranges == -1) {
   croak "An error has occurred";
}

print "Number of ranges for analog input channel $chan - $n_ranges\n";

Returns the number of ranges of the subdevice with the index subdev and the chan channel. This method returns -1 on error.

get_range

Range information of channel.

Example code,

# Read the range specification of the analog input channel $chan
my $range = $cref->get_range($subdev, $chan, $rng);
croak "Cannot read range specification" unless defined $range->{min};

# Print the minimal sample value of the given analog input channel
print "Analog input channel $chan min sample value - $range->{min}\n";

The class method get_range() returns a hash reference that contains information that can be used to convert sample values to or from physical units. If there is an error, undef is returned.

find_range

Search for range.

Example code,

my $rng_idx = $cref->find_range($subdev, $chan, $unit, $min, $max);

if ($rng_idx == -1) {
   print "No matching range available\n"
}
else {
   print "Found a matching range for channel $chan at index $rng_idx\n";
}

If a matching range is found, the index of the matching range is returned. If no matching range is available, the class method returns -1.

get_buffer_size

Streaming buffer size of subdevice.

Example code,

my $buf_size = $cref->get_buffer_size($subdev);
croak "An error has occurred" if $buf_size == -1;

print "Streaming buffer size for the subdevice - $buf_size Bytes\n";

This class method returns the size -in Bytes- of the streaming buffer for the specified subdevice. On error, -1 is returned.

get_max_buffer_size

Maximum streaming buffer size.

Example code,

my $max_size = $cref->get_max_buffer_size($subdev);
croak "An error has occurred" if $max_size == -1;

print "Max. streaming buffer size for the subdevice - $max_size Bytes\n";

This class method returns the maximum allowable size -in Bytes- of the streaming buffer for the specified subdevice. On error, -1 is returned.

set_buffer_size

Streaming buffer size of subdevice.

Example code,

# First, determine the virtual memory page size (look at the Comedi docu)
require POSIX;

my $vmps = POSIX::sysconf(&POSIX::_SC_PAGESIZE);
$vmps   *= 2;

print "Trying to set the streaming buffer size to $vmps\n";

if ($cref->set_buffer_size($subdev, $vmps) == -1) {
   print "Warning: Couldn't set new streaming buffer size\n";
}

The set_buffer_size() class method returns the new buffer size in Bytes. On error, -1 is returned.

do_insnlist

Perform multible instructions.

Example code,

my @insn_arr = ({
   insn      => Comedi::Lib::INSN_READ,
   n         => 2,
   data      => [0, 0],
   subdev    => 0,
   chanspec  => $cref->CR_PACK($chan, $rng, $aref)
}, {
   insn      => Comedi::Lib::INSN_WRITE,
   n         => 1,
   data      => [255],
   subdev    => 1,
   chanspec  => $cref->CR_PACK($chan, $rng, $aref)
});

# Now, create a comedi_insnlist like hash reference
my $comedi_insnlist = {
   n_insns => 2,
   insns   => [@insn_arr]
};

my $retval = $cref->do_insnlist($comedi_insnlist);
croak "An error has occurred" if $retval == -1;

print "[<1>] data (AI) - ", $insn_arr[0]->{data}[0], "\n";
print "[<2>] data (AI) - ", $insn_arr[0]->{data}[1], "\n";

This class method returns the number of successfully completed instructions. If there is an error before the first instruction can be executed, -1 is returned.

do_insn

Perform an instruction.

Example code,

# First, create a comedi_insn like hash reference
my $comedi_insn = {
   insn     => Comedi::Lib::INSN_READ,
   n        => 2,
   data     => [0, 0], 
   subdev   => 0,
   chanspec => $cref->CR_PACK($chan, $rng, $aref)
};

my $retval = $cref->do_insn($comedi_insn);
croak "An error has occured" if $retval == -1;

print "[<1>] data (AI) - ", $comedi_insn->{data}[0], "\n";
print "[<2>] data (AI) - ", $comedi_insn->{data}[1], "\n";

This class method returns the number of samples measured, which may be less than the number of requested samples. If there is an error before the first instruction can be executed, -1 is returned.

lock

Subdevice reservation.

Example code,

my $retval = $cref->lock($subdev);
croak "An error has occurred" if $retval == -1;

If successful, lock() returns 0. If there is an error, -1 is returned.

unlock

Subdevice reservation.

Example code,

my $retval = $cref->unlock($subdev);
croak "An error has occurred" if $retval == -1;

If successful, unlock() returns 0. If there is an error, -1 is returned.

data_read

Read single sample from channel.

Example code,

my $retval = $cref->data_read($subdev, $chan, $rng, $aref, \$data);
croak "An error hash occurred" if $retval == -1;

print "Have read a single sample value of $data\n";

On success, data_read() returns 1 (the number of samples read). If there is an error, -1 is returned.

data_read_delayed

Read single sample from channel after delaying for specified time.

Example code,

my $ret = $cref->data_read_delayed($subd, $chan, $rng, $aref, \$data, $ns);
croak "An error hash occurred" if $retval == -1;

print "Have read a single sample value of $data\n";

The return value of this class method is identical to the data_read() function.

data_read_hint

Tell driver which channel/range/aref you're going to read from next.

Example code

my $retval = $cref->data_read_hint($subdev, $chan, $rng, $aref);
croak "An error hash occurred" if $retval == -1;

The return value of this class method is identical to the data_read() function.

data_write

Write single sample to channel.

Example code,

my $retval = $cref->data_write($subdev, $chan, $rng, $aref, $data);
croak "An error hash occurred" if $retval == -1;

On success, data_write() returns 1 (the number of samples read). If there is an error, -1 is returned.

dio_config

Change input/output properties of channel.

Example code,

# For input
my $retval = $cref->dio_config($subdev, $chan, Comedi::Lib::COMEDI_INPUT);
croak "An error hash occurred" if $retval == -1;

# For output
my $retval = $cref->dio_config($subdev, $chan, Comedi::Lib::COMEDI_INPUT);
croak "An error hash occurred" if $retval == -1;

If successful, 1 is returned, otherwise -1.

dio_get_config

Query input/output properties of channel.

Example code,

my $retval = $cref->dio_get_config($subdev, $chan, \$dir);
croak "An error hash occurred" if $retval == -1;

if ($dir == Comedi::Lib::COMEDI_INPUT) {
   print "Input direction\n";
}
else { # Comedi::Lib::COMEDI_OUTPUT
   print "Output direction\n";
}

If successful, 0 is returned, otherwise -1.

dio_read

Read single bit from digital channel.

Example code,

my $retval = $cref->data_read($subdev, $chan, \$bit);
croak "An error has occurred" if $retval == -1;

print "Have read a data value of $bit\n";

Return values and errors are the same as data_read().

dio_write

Write single bit to digital channel.

Example code,

my $retval = $cref->data_write($subdev, $chan, $bit);
croak "An error has occurred" if $retval == -1;

Return values and errors are the same as data_write().

dio_bitfield2

Read/Write multible digital channels.

Example code,

my $retval = $cref->dio_bitfield2($subdev, $write_mask, \$bits, $base_ch);
croak "An error has occurred" if $retval == -1;

# Evaluate the $bits variable...

If successful, dio_bitfield2() returns 0. If there is an error, -1 is returned.

get_cmd_src_mask

Streaming input/output capabilities.

Note that this subroutine has no functionality as long as I have no testing device with the associated driver.

Patches or suggestions are welcome, send me an email (Subject: Comedi::Lib).

get_cmd_generic_timed

Streaming input/output capabilities.

Note that this subroutine has no functionality as long as I have no testing device with the associated driver.

Patches or suggestions are welcome, send me an email (Subject: Comedi::Lib).

cancel

Stop streaming input/output in progress.

Example code,

# This class method is useful in combination with command()
# and this class method is not completely implemented yet.

If successful, cancel() returns 0, otherwise -1.

command

Start streaming input/output.

Note that this subroutine has no functionality as long as I have no testing device with the associated driver.

Patches or suggestions are welcome, send me an email (Subject: Comedi::Lib).

command_test

Test streaming input/output configuration.

Note that this subroutine has no functionality as long as I have no testing device with the associated driver.

Patches or suggestions are welcome, send me an email (Subject: Comedi::Lib).

poll

Force updating of streaming buffer.

Example code,

my $retval = $cref->poll($subdev);
croak "An error has occurred" if $retval == -1;

If successful, this class method returns the number of additional bytes available. If there is an error, -1 is returned.

set_max_buffer_size

Streaming buffer size of subdevice.

Example code,

my $old_buf_size = $cref->set_max_buffer_size($subdev, $max_size);

if ($old_buf_size == -1) {
   croak "An error has occurred";
}
else {
   print "Buffer size changed from $old_buf_size to $max_size.\n";
}

If successful, the old buffer size is returned. On error, -1 is returned.

get_buffer_contents

Streaming buffer status.

Example code,

# This class method is useful in combination with command()
# and this class method is not completely implemented yet.

This class method returns the number of bytes that are available in the streaming buffer. If there is an error, -1 is returned.

mark_buffer_read

Streaming buffer control.

Example code,

# This class method is useful in combination with command()
# and this class method is not completely implemented yet.

The mark_buffer_read() class method returns the number of bytes successfully marked as read, or -1 on error.

mark_buffer_written

Streaming buffer control.

Example code,

# This class method is useful in combination with command()
# and this class method is not completely implemented yet.

The mark_buffer_written() class method returns the number of bytes successfully marked as written, or -1 on error.

get_buffer_offset

Streaming buffer status.

Example code,

# This class method is useful in combination with command()
# and this class method is not completely implemented yet.

This class method returns the offset in bytes of the read pointer in the streaming buffer. If there is an error, -1 is returned.

AUTHOR

Manuel Gebele <forensixs[at]gmx.de>

SUPPORT & DOCUMENTATION

After installing, you can find documentation for this module with the perldoc command

perldoc Comedi::Lib

or use the man command

man Comedi::Lib

You can also look for information at:

Search CPAN
   http://search.cpan.org/dist/Comedi-Lib

CPAN Request Tracker
   http://rt.cpan.org/NoAuth/Bugs.html?Dist=Comedi-Lib

AnnoCPAN, annotated CPAN documentation
   http://annocpan.org/dist/Comedi-Lib

CPAN Ratings
   http://cpanratings.perl.org/d/Comedi-Lib

Comedi
   http://www.comedi.org

BUGS

Please report any bugs or feature request to my email address, or through the web interface at http://rt.cpan.org/Public/Bug/Report.html?Queue=Comedi::Lib. I'll be notified, and then you'll automatically be notified of progess on your bug as I make changes.

COPYRIGHT & LICENSE

This program is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

To install Comedi::Lib, copy and paste the appropriate command in to your terminal.

cpanm

cpanm Comedi::Lib

CPAN shell

perl -MCPAN -e shell
install Comedi::Lib

For more information on module installation, please visit the detailed CPAN module installation guide.

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