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Create a package for the printer

master
parent
commit
c9e5b4d1e9
Signed by: p <p@janouch.name> GPG Key ID: A0420B94F92B9493
3 changed files with 237 additions and 93 deletions
  1. +9
    -57
      brother-info/main.go
  2. +10
    -36
      label-exp/main.go
  3. +218
    -0
      ql/ql.go

+ 9
- 57
brother-info/main.go View File

@@ -1,10 +1,9 @@
package main

import (
"io"
"log"
"os"
"time"
"janouch.name/sklad/ql"
)

func decodeBitfieldErrors(b byte, errors [8]string) []string {
@@ -19,25 +18,6 @@ func decodeBitfieldErrors(b byte, errors [8]string) []string {

// -----------------------------------------------------------------------------

type brotherStatus struct {
errors []string
}

// TODO: What exactly do we need? Probably extend as needed.
func decodeStatusInformation(d []byte) brotherStatus {
var status brotherStatus
status.errors = append(status.errors, decodeBitfieldErrors(d[8], [8]string{
"no media", "end of media", "cutter jam", "?", "printer in use",
"printer turned off", "high-voltage adapter", "fan motor error"})...)
status.errors = append(status.errors, decodeBitfieldErrors(d[9], [8]string{
"replace media", "expansion buffer full", "communication error",
"communication buffer full", "cover open", "cancel key",
"media cannot be fed", "system error"})...)
return status
}

// -----------------------------------------------------------------------------

func printStatusInformation(d []byte) {
if d[0] != 0x80 || d[1] != 0x20 || d[2] != 0x42 || d[3] != 0x34 {
log.Println("unexpected status fixed bytes")
@@ -157,51 +137,23 @@ func printStatusInformation(d []byte) {
}

func main() {
// Linux usblp module, located in /drivers/usb/class/usblp.c
// (at least that's where the trails go, I don't understand the code)
f, err := os.OpenFile("/dev/usb/lp0", os.O_RDWR, 0)
printer, err := ql.Open()
if err != nil {
log.Fatalln(err)
}
defer f.Close()

// Flush any former responses in the printer's queue.
for {
dummy := make([]byte, 32)
if _, err := f.Read(dummy); err == io.EOF {
break
}
}

// Clear the print buffer.
invalidate := make([]byte, 400)
if _, err := f.Write(invalidate); err != nil {
log.Fatalln(err)
if printer == nil {
log.Fatalln("no suitable printer found")
}
defer printer.Close()

// Initialize.
if _, err := f.WriteString("\x1b\x40"); err != nil {
if err := printer.Initialize(); err != nil {
log.Fatalln(err)
}

// Request status information.
if _, err := f.WriteString("\x1b\x69\x53"); err != nil {
status, err := printer.GetStatus()
if err != nil {
log.Fatalln(err)
}

// We need to poll the device.
status := make([]byte, 32)
for {
if n, err := f.Read(status); err == io.EOF {
time.Sleep(10 * time.Millisecond)
} else if err != nil {
log.Fatalln(err)
} else if n < 32 {
log.Fatalln("invalid read")
} else {
break
}
}

printStatusInformation(status)
}

+ 10
- 36
label-exp/main.go View File

@@ -18,6 +18,7 @@ import (
"github.com/boombuler/barcode/qr"

"janouch.name/sklad/bdf"
"janouch.name/sklad/ql"
)

// scaler is a scaling image.Image wrapper.
@@ -233,55 +234,28 @@ func printLabel(src image.Image) error {

// ---

// Linux usblp module, located in /drivers/usb/class/usblp.c
// (at least that's where the trails go, I don't understand the code)
f, err := os.OpenFile("/dev/usb/lp0", os.O_RDWR, 0)
printer, err := ql.Open()
if err != nil {
return err
}
defer f.Close()

// Flush any former responses in the printer's queue.
for {
dummy := make([]byte, 32)
if _, err := f.Read(dummy); err == io.EOF {
break
}
if printer == nil {
return errors.New("no suitable printer found")
}
defer printer.Close()

// Clear the print buffer.
invalidate := make([]byte, 400)
if _, err := f.Write(invalidate); err != nil {
if err := printer.Initialize(); err != nil {
return err
}

// Initialize.
if _, err := f.WriteString("\x1b\x40"); err != nil {
return err
}

// Request status information.
if _, err := f.WriteString("\x1b\x69\x53"); err != nil {
status, err := printer.GetStatus()
if err != nil {
return err
}

// We need to poll the device.
status := make([]byte, 32)
for {
if n, err := f.Read(status); err == io.EOF {
time.Sleep(10 * time.Millisecond)
} else if err != nil {
return err
} else if n < 32 {
return errors.New("invalid read")
} else {
break
}
}
printStatusInformation(status)

// Print the prepared data.
if _, err := f.Write(data); err != nil {
if _, err := printer.File.Write(data); err != nil {
return err
}

@@ -294,7 +268,7 @@ func printLabel(src image.Image) error {
if time.Now().Sub(start) > 3*time.Second {
break
}
if n, err := f.Read(status); err == io.EOF {
if n, err := printer.File.Read(status); err == io.EOF {
time.Sleep(100 * time.Millisecond)
} else if err != nil {
return err


+ 218
- 0
ql/ql.go View File

@@ -0,0 +1,218 @@
// Package ql is a Linux driver for Brother QL-series printers.
package ql

// Resources:
// http://www.undocprint.org/formats/page_description_languages/brother_p-touch

import (
"errors"
"io"
"os"
"path/filepath"
"regexp"
"strings"
"syscall"
"time"
"unsafe"
)

// #include <linux/ioctl.h>
import "C"

// -----------------------------------------------------------------------------

func _IOC(dir, typ, nr, size int) uintptr {
return (uintptr(dir) << C._IOC_DIRSHIFT) |
(uintptr(typ) << C._IOC_TYPESHIFT) |
(uintptr(nr) << C._IOC_NRSHIFT) |
(uintptr(size) << C._IOC_SIZESHIFT)
}

const (
iocnrGetDeviceID = 1
)

// lpiocGetDeviceID reads the IEEE-1284 Device ID string of a printer.
func lpiocGetDeviceID(fd uintptr) ([]byte, error) {
var buf [1024]byte
if _, _, err := syscall.Syscall(syscall.SYS_IOCTL, fd,
_IOC(C._IOC_READ, 'P', iocnrGetDeviceID, len(buf)),
uintptr(unsafe.Pointer(&buf))); err != 0 {
return nil, err
}

// In theory it might get trimmed along the way.
length := int(buf[0])<<8 | int(buf[1])
if 2+length > len(buf) {
return buf[2:], errors.New("the device ID string got trimmed")
}

return buf[2 : 2+length], nil
}

// -----------------------------------------------------------------------------

var deviceIDRegexp = regexp.MustCompile(
`(?s:\s*([^:,;]+?)\s*:\s*([^:;]*)\s*(?:;|$))`)

type deviceID map[string][]string

// parseIEEE1284DeviceID leniently parses an IEEE 1284 Device ID string
// and returns a map containing a slice of values for each key.
//
// See e.g. http://www.undocprint.org/formats/communication_protocols/ieee_1284
func parseIEEE1284DeviceID(id []byte) deviceID {
m := make(deviceID)
for _, kv := range deviceIDRegexp.FindAllStringSubmatch(string(id), -1) {
var values []string
for _, v := range strings.Split(kv[2], ",") {
values = append(values, strings.Trim(v, "\t\n\v\f\r "))
}
m[kv[1]] = values
}
return m
}

func (id deviceID) Find(key, abbreviation string) []string {
if values, ok := id[key]; ok {
return values
}
if values, ok := id[abbreviation]; ok {
return values
}
return nil
}

// -----------------------------------------------------------------------------

type Printer struct {
File *os.File
}

func compatible(id deviceID) bool {
for _, commandSet := range id.Find("COMMAND SET", "CMD") {
if commandSet == "PT-CBP" {
return true
}
}
return false
}

// Open finds and initializes the first USB printer found supporting
// the appropriate protocol. Returns nil if no printer could be found.
func Open() (*Printer, error) {
// Linux usblp module, located in /drivers/usb/class/usblp.c
paths, err := filepath.Glob("/dev/usb/lp[0-9]*")
if err != nil {
return nil, err
}
for _, candidate := range paths {
f, err := os.OpenFile(candidate, os.O_RDWR, 0)
if err != nil {
continue
}
// Filter out obvious non-printers.
deviceID, err := lpiocGetDeviceID(f.Fd())
if err != nil {
f.Close()
continue
}
// Filter out printers that wouldn't understand the protocol.
if !compatible(parseIEEE1284DeviceID(deviceID)) {
f.Close()
continue
}
return &Printer{File: f}, nil
}
return nil, nil
}

// Initialize initializes the printer for further operations.
func (p *Printer) Initialize() error {
// Clear the print buffer.
invalidate := make([]byte, 400)
if _, err := p.File.Write(invalidate); err != nil {
return err
}

// Initialize.
if _, err := p.File.WriteString("\x1b\x40"); err != nil {
return err
}

// Flush any former responses in the printer's queue.
//
// I'm not sure if this is necessary, or rather whether the kernel driver
// does any buffering that could cause data to be returned at this point.
/*
for {
dummy := make([]byte, 32)
if _, err := f.Read(dummy); err == io.EOF {
break
}
}
*/

return nil
}

// GetStatus retrieves the printer's status as raw data. The printer must be
// in an appropriate mode, i.e. on-line and not currently printing.
func (p *Printer) GetStatus() ([]byte, error) {
// Request status information.
if _, err := p.File.WriteString("\x1b\x69\x53"); err != nil {
return nil, err
}

// We need to poll the device a bit.
status := make([]byte, 32)
start := time.Now()
for {
if n, err := p.File.Read(status); err == io.EOF {
time.Sleep(10 * time.Millisecond)
} else if err != nil {
return nil, err
} else if n < 32 {
return nil, errors.New("invalid read")
} else {
return status, nil
}
if time.Now().Sub(start) > time.Second {
return nil, errors.New("timeout")
}
}
}

// Close closes the underlying file.
func (p *Printer) Close() error {
return p.File.Close()
}

// -----------------------------------------------------------------------------

type Status struct {
errors []string
}

func decodeBitfieldErrors(b byte, errors [8]string) []string {
var result []string
for i := uint(0); i < 8; i++ {
if b&(1<<i) != 0 {
result = append(result, errors[i])
}
}
return result
}

// TODO: What exactly do we need? Probably extend as needed.
func decodeStatusInformation(d []byte) Status {
var status Status
status.errors = append(status.errors, decodeBitfieldErrors(d[8], [8]string{
"no media", "end of media", "cutter jam", "?", "printer in use",
"printer turned off", "high-voltage adapter", "fan motor error"})...)
status.errors = append(status.errors, decodeBitfieldErrors(d[9], [8]string{
"replace media", "expansion buffer full", "communication error",
"communication buffer full", "cover open", "cancel key",
"media cannot be fed", "system error"})...)
return status
}

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