mirror of
https://github.com/42wim/matterbridge
synced 2024-11-09 07:10:25 +00:00
81 lines
2.8 KiB
Markdown
81 lines
2.8 KiB
Markdown
|
# go-qrcode #
|
||
|
|
|
||
|
|
<img src='https://skip.org/img/nyancat-youtube-qr.png' align='right'>
|
||
|
|
|
||
|
|
Package qrcode implements a QR Code encoder. [](https://travis-ci.org/skip2/go-qrcode)
|
||
|
|
|
||
|
|
A QR Code is a matrix (two-dimensional) barcode. Arbitrary content may be encoded, with URLs being a popular choice :)
|
||
|
|
|
||
|
|
Each QR Code contains error recovery information to aid reading damaged or obscured codes. There are four levels of error recovery: Low, medium, high and highest. QR Codes with a higher recovery level are more robust to damage, at the cost of being physically larger.
|
||
|
|
|
||
|
|
## Install
|
||
|
|
|
||
|
|
go get -u github.com/skip2/go-qrcode/...
|
||
|
|
|
||
|
|
A command-line tool `qrcode` will be built into `$GOPATH/bin/`.
|
||
|
|
|
||
|
|
## Usage
|
||
|
|
|
||
|
|
import qrcode "github.com/skip2/go-qrcode"
|
||
|
|
|
||
|
|
- **Create a PNG image:**
|
||
|
|
|
||
|
|
var png []byte
|
||
|
|
png, err := qrcode.Encode("https://example.org", qrcode.Medium, 256)
|
||
|
|
|
||
|
|
- **Create a PNG image and write to a file:**
|
||
|
|
|
||
|
|
err := qrcode.WriteFile("https://example.org", qrcode.Medium, 256, "qr.png")
|
||
|
|
|
||
|
|
- **Create a PNG image with custom colors and write to file:**
|
||
|
|
|
||
|
|
err := qrcode.WriteColorFile("https://example.org", qrcode.Medium, 256, color.Black, color.White, "qr.png")
|
||
|
|
|
||
|
|
All examples use the qrcode.Medium error Recovery Level and create a fixed
|
||
|
|
256x256px size QR Code. The last function creates a white on black instead of black
|
||
|
|
on white QR Code.
|
||
|
|
|
||
|
|
The maximum capacity of a QR Code varies according to the content encoded and
|
||
|
|
the error recovery level. The maximum capacity is 2,953 bytes, 4,296
|
||
|
|
alphanumeric characters, 7,089 numeric digits, or a combination of these.
|
||
|
|
|
||
|
|
## Documentation
|
||
|
|
|
||
|
|
[](https://godoc.org/github.com/skip2/go-qrcode)
|
||
|
|
|
||
|
|
## Demoapp
|
||
|
|
|
||
|
|
[http://go-qrcode.appspot.com](http://go-qrcode.appspot.com)
|
||
|
|
|
||
|
|
## CLI
|
||
|
|
|
||
|
|
A command-line tool `qrcode` will be built into `$GOPATH/bin/`.
|
||
|
|
|
||
|
|
```
|
||
|
|
qrcode -- QR Code encoder in Go
|
||
|
|
https://github.com/skip2/go-qrcode
|
||
|
|
|
||
|
|
Flags:
|
||
|
|
-o string
|
||
|
|
out PNG file prefix, empty for stdout
|
||
|
|
-s int
|
||
|
|
image size (pixel) (default 256)
|
||
|
|
|
||
|
|
Usage:
|
||
|
|
1. Arguments except for flags are joined by " " and used to generate QR code.
|
||
|
|
Default output is STDOUT, pipe to imagemagick command "display" to display
|
||
|
|
on any X server.
|
||
|
|
|
||
|
|
qrcode hello word | display
|
||
|
|
|
||
|
|
2. Save to file if "display" not available:
|
||
|
|
|
||
|
|
qrcode "homepage: https://github.com/skip2/go-qrcode" > out.png
|
||
|
|
```
|
||
|
|
|
||
|
|
## Links
|
||
|
|
|
||
|
|
- [http://en.wikipedia.org/wiki/QR_code](http://en.wikipedia.org/wiki/QR_code)
|
||
|
|
- [ISO/IEC 18004:2006](http://www.iso.org/iso/catalogue_detail.htm?csnumber=43655) - Main QR Code specification (approx CHF 198,00)<br>
|
||
|
|
- [https://github.com/qpliu/qrencode-go/](https://github.com/qpliu/qrencode-go/) - alternative Go QR encoding library based on [ZXing](https://github.com/zxing/zxing)
|