escpos

package module
v1.1.1 Latest Latest
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 Go to latest Published: Jun 27, 2022 License: MIT Imports: 28 Imported by: 0

README

About escpos

This is a simple Go package that provides ESC-POS library functions to help with sending control codes to a ESC-POS capable printer such as an Epson TM-T82 or similar.

These printers are often used in retail environments in conjunction with a point-of-sale (POS) system.

Installation

Install the package via the following:

go get -u github.com/cloudinn/escpos

Example epos-server

An example EPOS server implementation is available in the cmd/epos-server subdirectory of this project. This example server is more or less compatible with Epson TM-Intelligent printers and print server implementations.

Usage

The escpos package can be used similarly to the following:

package main

import (
    "bufio"
    "os"

    "github.com/cloudinn/escpos"
)

func main() {
    f, err := os.Open("/dev/usb/lp0")
    if err != nil {
        panic(err)
    }
    defer f.Close()

    w := bufio.NewWriter(f)
    p := escpos.New(w)

    p.Init()
    p.SetSmooth(1)
    p.SetFontSize(2, 3)
    p.SetFont("A")
    p.Write("test ")
    p.SetFont("B")
    p.Write("test2 ")
    p.SetFont("C")
    p.Write("test3 ")
    p.Formfeed()

    p.SetFont("B")
    p.SetFontSize(1, 1)

    p.SetEmphasize(1)
    p.Write("halle")
    p.Formfeed()

    p.SetUnderline(1)
    p.SetFontSize(4, 4)
    p.Write("halle")

    p.SetReverse(1)
    p.SetFontSize(2, 4)
    p.Write("halle")
    p.Formfeed()

    p.SetFont("C")
    p.SetFontSize(8, 8)
    p.Write("halle")
    p.FormfeedN(5)

    p.Cut()
    p.End()

    w.Flush()
}

NOTE

The Imported font inside the code is a system font called DejaVuSansMono-Bold.ttfsoyou shoukd make sure it exists in the system and it'splaced in the "/usr/share/fonts/truetype/dejavu/"

TODO

  • Fix barcode support

Credits

Documentation

Index

Constants

View Source 
const (
	// DefaultEndpoint is the default server endpoint for ePOS printers.
	DefaultEndpoint = "/cgi-bin/epos/service.cgi"
)

Variables

View Source 
var (
	// ErrBodyElementEmpty is the body element empty error.
	ErrBodyElementEmpty = errors.New("Body element empty")
)

Functions

This section is empty.

Types

type Printer 

type Printer struct {
	sync.Mutex
	// contains filtered or unexported fields
}

Printer wraps sending ESC-POS commands to a io.Writer.

func NewPrinter 

func NewPrinter(w io.ReadWriter) (*Printer, error)

NewPrinter creates a new printer using the specified writer.

func (*Printer) Barcode 

func (p *Printer) Barcode(barcode string, format int)

Barcode sends a barcode to the printer.

func (*Printer) Cash 

func (p *Printer) Cash()

Cash writes the cash code to the printer.

func (*Printer) CloseConnection 

func (p *Printer) CloseConnection() error

func (*Printer) Cut 

func (p *Printer) Cut()

Cut writes the cut code to the printer.

func (*Printer) End 

func (p *Printer) End()

End terminates the printer session.

func (*Printer) Feed 

func (p *Printer) Feed(params map[string]string) error

Feed feeds the printer, applying the supplied params as necessary.

func (*Printer) FeedAndCut 

func (p *Printer) FeedAndCut(params map[string]string)

FeedAndCut feeds the printer using the supplied params and then sends a cut command.

func (*Printer) Formfeed 

func (p *Printer) Formfeed()

Formfeed writes 1 formfeed to the printer.

func (*Printer) FormfeedN 

func (p *Printer) FormfeedN(n int)

FormfeedN writes N formfeeds to the printer.

func (*Printer) Image 

func (p *Printer) Image(params map[string]string, data string) error

Image writes an image using the supplied params.

func (*Printer) Init 

func (p *Printer) Init()

Init resets the state of the printer, and writes the initialize code.

func (*Printer) Linefeed 

func (p *Printer) Linefeed()

Linefeed writes a line end to the printer.

func (*Printer) PrintImage 

func (p *Printer) PrintImage(imgPath string, printImageType string) error

PrintImage Print Image

func (*Printer) PrintTextImage 

func (p *Printer) PrintTextImage(text string) error

PrintTextImage takes a string convert it to an image and print it

func (*Printer) Pulse 

func (p *Printer) Pulse()

Pulse sends the pulse (open drawer) code to the printer.

func (*Printer) Raster 

func (p *Printer) Raster(width, height, lineWidth int, imgBw []byte, printingType string)

Raster writes a rasterized version of a black and white image to the printer with the specified width, height, and lineWidth bytes per line.

func (*Printer) ReadStatus 

func (p *Printer) ReadStatus() bool

func (*Printer) Reset 

func (p *Printer) Reset()

Reset resets the printer state.

func (*Printer) SendEmphasize 

func (p *Printer) SendEmphasize()

SendEmphasize sends the emphasize / doublestrike command to the printer.

func (*Printer) SendFontSize 

func (p *Printer) SendFontSize()

SendFontSize sends the font size command to the printer.

func (*Printer) SendMoveX 

func (p *Printer) SendMoveX(x uint16)

SendMoveX sends the move x command to the printer.

func (*Printer) SendMoveY 

func (p *Printer) SendMoveY(y uint16)

SendMoveY sends the move y command to the printer.

func (*Printer) SendReverse 

func (p *Printer) SendReverse()

SendReverse sends the reverse command to the printer.

func (*Printer) SendRotate 

func (p *Printer) SendRotate()

SendRotate sends the rotate command to the printer.

func (*Printer) SendSmooth 

func (p *Printer) SendSmooth()

SendSmooth sends the smooth command to the printer.

func (*Printer) SendUnderline 

func (p *Printer) SendUnderline()

SendUnderline sends the underline command to the printer.

func (*Printer) SendUpsidedown 

func (p *Printer) SendUpsidedown()

SendUpsidedown sends the upsidedown command to the printer.

func (*Printer) SetAlign 

func (p *Printer) SetAlign(align string)

SetAlign sets the alignment state and sends it to the printer.

func (*Printer) SetDPI 

func (p *Printer) SetDPI(resolution float64)

SetDPI sets resolution in dots per inch for the image

func (*Printer) SetEmphasize 

func (p *Printer) SetEmphasize(u byte)

SetEmphasize sets the emphasize state and sends it to the printer.

func (*Printer) SetFont 

func (p *Printer) SetFont(font string)

SetFont sets the font on the printer.

func (*Printer) SetFontFile 

func (p *Printer) SetFontFile(filepath string)

SetFontFile to choose a certien font to print the image with

func (*Printer) SetFontSize 

func (p *Printer) SetFontSize(width, height byte)

SetFontSize sets the font size state and sends the command to the printer.

func (*Printer) SetFontSizePoints 

func (p *Printer) SetFontSizePoints(fontSize float64)

SetFontSizePoint sets font size in points for some selected font

func (*Printer) SetHinting 

func (p *Printer) SetHinting(hintingVal string)

SetHinting sets hinting

func (*Printer) SetImageHight 

func (p *Printer) SetImageHight(hight int)

func (*Printer) SetLang 

func (p *Printer) SetLang(lang string)

SetLang sets the language state and sends it to the printer.

func (*Printer) SetReverse 

func (p *Printer) SetReverse(v byte)

SetReverse sets the reverse state and sends it to the printer.

func (*Printer) SetRotate 

func (p *Printer) SetRotate(v byte)

SetRotate sets the rotate state and sends it to the printer.

func (*Printer) SetSmooth 

func (p *Printer) SetSmooth(v byte)

SetSmooth sets the smooth state and sends it to the printer.

func (*Printer) SetSpacing 

func (p *Printer) SetSpacing(spacingVal float64)

SetSpacing set spacing between lines in image

func (*Printer) SetUnderline 

func (p *Printer) SetUnderline(v byte)

SetUnderline sets the underline state and sends it to the printer.

func (*Printer) SetUpsidedown 

func (p *Printer) SetUpsidedown(v byte)

SetUpsidedown sets the upsidedown state and sends it to the printer.

func (*Printer) SetWhiteOnBlack 

func (p *Printer) SetWhiteOnBlack(wonbVal bool)

SetWhiteOnBlack sets the background for the image to white for true or black for false

func (*Printer) Text 

func (p *Printer) Text(params map[string]string, text string) error

Text sends a block of text to the printer using the formatting parameters in params.

func (*Printer) TextToRaster 

func (p *Printer) TextToRaster(text string, fontSize float64, wb bool) (data []byte, width int, height int, err error)

TextToRaster takes a string, font size, boolean value if true will print text black background white if false will print text white background black return slice bytes of raster image with width and height

func (*Printer) Write 

func (p *Printer) Write(buf []byte) (int, error)

Write writes buf to printer.

func (*Printer) WriteNode 

func (p *Printer) WriteNode(name string, params map[string]string, data string)

WriteNode writes a node of type name with the supplied params and data to the printer.

func (*Printer) WriteString 

func (p *Printer) WriteString(s string) (int, error)

WriteString writes a string to the printer.

type Server 

type Server struct {
	// contains filtered or unexported fields
}

Server wrap

func NewServer 

func NewServer(w io.ReadWriter, opts ...ServerOption) (*Server, error)

NewServer creates a new ePOS server.

func (*Server) ServeHTTP 

func (s *Server) ServeHTTP(res http.ResponseWriter, req *http.Request)

ServeHTTP handles OPTIONS, Origin, and POST for an ePOS server.

type ServerOption 

type ServerOption func(*Server) error

ServerOption is a server option.

func WithLog 

func WithLog(f func(string, ...interface{})) ServerOption

WithLog is a server option to set a logging func.

Source Files

View all Source files

Directories

Path Synopsis
cmd
epos-server
example
image2pos

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