77 lines
1.5 KiB
Go
77 lines
1.5 KiB
Go
package main
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import "fmt"
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import "log"
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import "os"
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import "strconv"
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import "strings"
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const (
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markerMiles = "mi"
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markerKm = "km"
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markerFeet = "ft"
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markerMeter = "m"
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MilesToKm float64 = 1.609344
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FeetsToMeters float64 = 3.28084
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)
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var (
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inUnit string
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inVal float64
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asMeter float64
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err error
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convVal float64
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)
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func main() {
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if len(os.Args) < 3 {
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log.Fatalln("Needs 2 arguments")
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}
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input := os.Args[1]
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convTo := os.Args[2]
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switch {
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case strings.HasSuffix(input, markerKm):
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inUnit = markerKm
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case strings.HasSuffix(input, markerFeet):
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inUnit = markerFeet
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case strings.HasSuffix(input, markerMeter):
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inUnit = markerMeter
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case strings.HasSuffix(input, markerMiles):
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inUnit = markerMiles
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default:
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log.Fatalln("Invalid input:", input)
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}
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inVal, err = strconv.ParseFloat(input[:len(input)-len(inUnit)], 64)
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if err != nil {
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log.Fatalln("Invalid input number", err)
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}
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switch inUnit {
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case markerMiles:
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asMeter = inVal * MilesToKm * 1000
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case markerKm:
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asMeter = inVal * 1000
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case markerFeet:
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asMeter = inVal * FeetsToMeters
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case markerMeter:
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asMeter = inVal
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}
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// fmt.Println(inVal, inUnit, asMeter, convTo)
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switch convTo {
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case markerMiles:
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convVal = asMeter / (MilesToKm * 1000)
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case markerKm:
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convVal = asMeter / 1000
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case markerFeet:
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convVal = asMeter / FeetsToMeters
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case markerMeter:
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convVal = asMeter
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default:
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log.Fatalln("Invalid unit: " + convTo)
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}
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fmt.Printf("%.2f%s\n", convVal, convTo)
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}
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