Initial commit

go.mod

@@ -0,0 +1,14 @@
+module dmesg
+
+go 1.22.5
+
+require (
+	github.com/alexjch/go-dmesg v0.0.1 // indirect
+	github.com/gokrazy/gokrazy v0.0.0-20250128195218-b3656e138176 // indirect
+	github.com/gokrazy/internal v0.0.0-20240629150625-a0f1dee26ef5 // indirect
+	github.com/google/renameio/v2 v2.0.0 // indirect
+	github.com/kenshaw/evdev v0.1.0 // indirect
+	github.com/mdlayher/watchdog v0.0.0-20201005150459-8bdc4f41966b // indirect
+	github.com/spf13/pflag v1.0.5 // indirect
+	golang.org/x/sys v0.20.0 // indirect
+)

go.sum

@@ -0,0 +1,17 @@
+github.com/alexjch/go-dmesg v0.0.1 h1:9OCcZIsb9c/+P5gl+w8DpKXYi7I6aaINlQgkEiz9OCw=
+github.com/alexjch/go-dmesg v0.0.1/go.mod h1:wSeufifwO3dOS31bBz+ovoEahUflK1kQo8uB+pvPOcg=
+github.com/gokrazy/gokrazy v0.0.0-20250128195218-b3656e138176 h1:zRHdeXtfNyir8WOKPYW/C4GH1l7Y/41iGYWzBoDOw8I=
+github.com/gokrazy/gokrazy v0.0.0-20250128195218-b3656e138176/go.mod h1:1yOdp952OIkgR9lBNUzV+mBSIcvPV0RCaCmBq9WKTJw=
+github.com/gokrazy/internal v0.0.0-20240629150625-a0f1dee26ef5 h1:XDklMxV0pE5jWiNaoo5TzvWfqdoiRRScmr4ZtDzE4Uw=
+github.com/gokrazy/internal v0.0.0-20240629150625-a0f1dee26ef5/go.mod h1:t3ZirVhcs9bH+fPAJuGh51rzT7sVCZ9yfXvszf0ZjF0=
+github.com/google/renameio/v2 v2.0.0 h1:UifI23ZTGY8Tt29JbYFiuyIU3eX+RNFtUwefq9qAhxg=
+github.com/google/renameio/v2 v2.0.0/go.mod h1:BtmJXm5YlszgC+TD4HOEEUFgkJP3nLxehU6hfe7jRt4=
+github.com/kenshaw/evdev v0.1.0 h1:wmtceEOFfilChgdNT+c/djPJ2JineVsQ0N14kGzFRUo=
+github.com/kenshaw/evdev v0.1.0/go.mod h1:B/fErKCihUyEobz0mjn2qQbHgyJKFQAxkXSvkeeA/Wo=
+github.com/mdlayher/watchdog v0.0.0-20201005150459-8bdc4f41966b h1:7tUBfsEEBWfFeHOB7CUfoOamak+Gx/BlirfXyPk1WjI=
+github.com/mdlayher/watchdog v0.0.0-20201005150459-8bdc4f41966b/go.mod h1:bmoJUS6qOA3uKFvF3KVuhf7mU1KQirzQMeHXtPyKEqg=
+github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
+github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
+golang.org/x/sys v0.0.0-20201005065044-765f4ea38db3/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.20.0 h1:Od9JTbYCk261bKm4M/mw7AklTlFYIa0bIp9BgSm1S8Y=
+golang.org/x/sys v0.20.0/go.mod h1:/VUhepiaJMQUp4+oa/7Zr1D23ma6VTLIYjOOTFZPUcA=

main.go

@@ -0,0 +1,71 @@
+// SPDX-License-Identifier: MIT
+package main
+
+import (
+	"bufio"
+	"fmt"
+	"os"
+	"os/signal"
+	"syscall"
+
+	"github.com/alexjch/go-dmesg/pkg/dmesg"
+	"github.com/gokrazy/gokrazy"
+)
+
+// Primitives are:
+//   - scanner, a bufio.Scanner that reads from /dev/kmsg
+//   - decoder, a dmesg.Decoder that wraps a scanner and decodes log records
+//     {decoder{scanner}}}
+var LEVELS = map[uint8]string{
+	0: "Emergency",
+	1: "Alert",
+	2: "Critical",
+	3: "Error",
+	4: "Warning",
+	5: "Notice",
+	6: "Info",
+	7: "Debug",
+}
+
+func NewScanner() (*dmesg.Scanner, error) {
+	// Open /dev/kmsg for reading in a non-blocking manner
+	f, err := os.OpenFile("/dev/kmsg", syscall.O_RDONLY|syscall.O_NONBLOCK, 0)
+	if err != nil {
+		return nil, fmt.Errorf("Failed to open kernel log: %w", err)
+	}
+	f.Seek(0, 3)
+	// Wrap an os.File in a bufio.Scanner
+	scanner := bufio.NewScanner(f)
+	return &dmesg.Scanner{
+		Scanner:    *scanner,
+		ReadCloser: f,
+	}, nil
+}
+func main() {
+	gokrazy.WaitForClock()
+	// Handle Ctrl-C
+	c := make(chan os.Signal, 1)
+	signal.Notify(c, os.Interrupt)
+	// Create a scanner
+	scan, err := NewScanner()
+	if err != nil {
+		panic(err)
+	}
+	defer scan.Close()
+	// Create a decoder
+	dec, err := dmesg.NewDecoder(scan)
+	if err != nil {
+		panic(err)
+	}
+	// Stop the decoder when Ctrl-C is pressed
+	go func() {
+		<-c
+		dec.Stop()
+	}()
+	// Follow the decoder until Ctrl-C is pressed
+	if err := dec.Follow(func(r *dmesg.Record) {
+		fmt.Printf("%9s: %v: %s\n", LEVELS[r.Priority], r.Timestamp, r.Message)
+	}); err != nil {
+		panic(err)
+	}
+}