There is a function for this in the math lib Float64Frombits, a similar question: https://stackoverflow.com/questions/22491876/convert-byte-array-uint8-to-float64-in-golang
On Friday, 18 May 2018 10:31:11 UTC+8, John Fox wrote: > > Hello all. I am creating a custom exporter for FreeNAS > https://github.com/Maelos/freenas_exporter and am stuck on the conversion > of the string of bytes provided by the commands output to a float. Here is > my code, what I have tried, and my results: > > What I have tried and results (commented so you can try and see each > https://play.golang.org/p/sevfk7Nt2w4 > > Attempt 1 = binary.LittleEndian.Uint64([]bytes) to math.Float64frombits > Attempt 2 = bytes to string, String to float (strconv) > Attempt 3 = Bytes to bytes.Reader to binary.Read(slice of bytes, > binary.LittleEndian, floatVariableToFill) to error check > > Please let me know what more I can provide. I will keep hacking away at > it tomorrow, but hoping I can get this done soon. Full go play write up > below: > > package main > > > import ( > //You may need to edit these in or out depending upon the attempt > "bytes" > "encoding/binary" > "fmt" > //"strconv" > //"math" > ) > > > func main() { > > > // I have been able to test this part and I do get a return of "[50 10]" > which is correct (converts string "2" for 2 CPUs). The exact statement may > be a bit different. > // I am running the script on the latest FreeNAS whic his built from > 11.1STABLE FreeBSD. I have Go installed and am building the files on the > shell > //numCPUCmd := exec.Command("bash", "-c","/usr/local/bin/ipmitool -I > lanplus -H ipmiAddress -U ipmiUser -f /root/ipmi_password sdr elist all | > grep -c -i \"cpu.*temp\"") > //numCPUBytes, _ := numCPUCmd.Output() //returns a slice of bytes and an > error > > > > > // ATTEMPT 1 > var flty float64 > sob := []byte{50, 10} > fmt.Printf("\n%T %v\n\n", sob, sob) > > > buf := bytes.NewReader(sob) > err := binary.Read(buf, binary.LittleEndian, &flty) > if err != nil { > fmt.Println("binary.Read failed:", err) > } > fmt.Println(flty) > > /*Result > []uint8 [50 10] > > > binary.Read failed: unexpected EOF > 0 > */ > > //////////////////////////////////////////////////////// > //ATTEMPT 2 > /* > var f float64 > text := []byte{50, 10} // A decimal value represented as Latin-1 text > > > f, err := strconv.ParseFloat(string(text), 64) > if err != nil { > panic(err) > } > fmt.Println(f) > */ > /*Result > panic: strconv.ParseFloat: parsing "2\n": invalid syntax > > > goroutine 1 [running]: > main.main() > /tmp/sandbox657430918/main.go:44 +0x160 > */ > > //////////////////////////////////////////////// > //ATTEMPT3 > /* > sob := []byte{50, 10} > bits := binary.LittleEndian.Uint64(sob) > fmt.Printf("\n\n%T %v\n\n", bits, bits) > > > flty := math.Float64frombits(bits) > fmt.Printf("\n\n%T %v\n\n", flty, flty) > > > inty := int(flty) > fmt.Printf("\n\n%T %v\n\n", inty, inty) > */ > /* Result > panic: runtime error: index out of range > > > goroutine 1 [running]: > encoding/binary.binary.littleEndian.Uint64(...) > /usr/local/go/src/encoding/binary/binary.go:76 > main.main() > /tmp/sandbox742704811/main.go:62 +0x20 > */ > } > > -- You received this message because you are subscribed to the Google Groups "golang-nuts" group. To unsubscribe from this group and stop receiving emails from it, send an email to golang-nuts+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
