Finished linux basic cpu diagnostics

internal/processor/linux_cpu.go

@@ -8,40 +8,73 @@ import (
 	"log"
 	"os"
 	"regexp"
+	"strconv"
 	"strings"
 )
 
 var numberRegex *regexp.Regexp = regexp.MustCompile(`\d+`)
 
 func getLinuxCpuInfo() (ProcessorInformation, error) {
-	procFile, err := os.Open("/proc/loadavg")
+	procFile, err := os.Open("/proc/stat")
 	if err != nil {
-		return ProcessorInformation{}, fmt.Errorf("Could not find /proc/meminfo. Are you sure you are on linux?")
+		return ProcessorInformation{}, fmt.Errorf("Could not find /proc/stat. Are you sure you are on linux?")
 	}
 	defer procFile.Close()
 
 	fileReader := bufio.NewScanner(procFile)
 
-	//var idleTime uint64
-	//var kernelTime uint64
-	//var userTime uint64
+	var idleTime uint64
+	var nice uint64
+	var kernelTime uint64
+	var userTime uint64
+	var iowait uint64
+	var irq uint64
+	var softirq uint64
 
-	for fileReader.Scan() {
+	for linesExtracted := 0; fileReader.Scan(); linesExtracted++ {
 		line := fileReader.Text()
 
 		if strings.HasPrefix(line, "cpu ") {
+			/*
+			* fields[0] name of the core, we are extracting the first row so "total cpu", we don't care about subsequent cores (yet?)
+			* fields[1] a useless space to skip
+			* fields[2] cpu ticks spent on user processes
+			* fields[3] cpu ticks spent on low priority processes
+			* fields[4] cpu ticks spent on kernel processes
+			* fields[5] idle time measured in cpu ticks
+			* fields[6] cpu ticks spent on iowait (disk/network)
+			* fields[7] irq (hardware interrupt)
+			* fields[8] softirq (software interrupt)
+			* fields[9] steal < for virtualization
+			* fields[10] guest < for virtualization
+			* fields[11] guest_nice < for virtualization
+			 */
 			fields := strings.Split(line, " ")
-			for _, field := range fields {
-				fmt.Print(field)
-			}
+
+			userTime, _ = strconv.ParseUint(fields[2], 10, 64)
+			nice, _ = strconv.ParseUint(fields[3], 10, 64)
+			kernelTime, _ = strconv.ParseUint(fields[4], 10, 64)
+			idleTime, _ = strconv.ParseUint(fields[5], 10, 64)
+			iowait, _ = strconv.ParseUint(fields[6], 10, 64)  // a type of idle time
+			irq, _ = strconv.ParseUint(fields[7], 10, 64)     // active time
+			softirq, _ = strconv.ParseUint(fields[8], 10, 64) // active time
+		}
+
+		// ? Possibly extract more rows later on, for example breaking down each core and not just the combined value
+		if linesExtracted >= 1 {
+			break
 		}
 	}
 
 	if fileReader.Err() != nil {
-		return ProcessorInformation{}, fmt.Errorf("There was an error while reading /proc/meninfo. Error: %v", fileReader.Err())
+		return ProcessorInformation{}, fmt.Errorf("There was an error while reading /proc/stat. Error: %v", fileReader.Err())
 	}
 
-	return ProcessorInformation{}, nil
+	return ProcessorInformation{
+		IdleTimeSinceBoot:   idleTime + iowait,
+		KernelTimeSinceBoot: kernelTime + irq + softirq,
+		UserTimeSinceBoot:   userTime + nice,
+	}, nil
 }
 
 func GetCPUInformation() ProcessorInformation {