calculate disk usage in golang (Linux only) by parse output of command `df`

diskusage.go

import(
     "fmt"
     "strconv"
     "strings"
     "os/exec"
     "log"
)
 
func main() {
    out, _ := exec.Command("df", "-P").Output()
    ret, err := parseDfOutput(string(out))
    if err != nil {
        log.Println(err)
    }   
    fmt.Println(ret)
}
 
func parseDfOutput(out string) (float64, error) {
    outlines := strings.Split(out, "\n")
    l := len(outlines)
    var total, used float64 = 0, 0
    for _, line := range outlines[1:l-1] {
        parsedLine := strings.Fields(line)
        t, err := strconv.ParseFloat(parsedLine[1], 64) 
        if err != nil {
            return 0, err   
        }   
        u, err := strconv.ParseFloat(parsedLine[2], 64) 
        if err != nil {
            return 0, err 
        }   
        total += t
        used += u
    }   
    return used/total, nil 
}