Added flag to introduce cursor starting positions

cmd/micro/buffer.go

@@ -8,6 +8,8 @@ import (
 	"os/exec"
 	"os/signal"
 	"path/filepath"
+	"strconv"
+	"strings"
 	"time"
 	"unicode/utf8"
 )
@@ -85,10 +87,36 @@ func NewBuffer(txt []byte, path string) *Buffer {
 	}
 
 	// Put the cursor at the first spot
+	cursorStartX := 0
+	cursorStartY := 0
+	// If -cursor LINE,COL was passed, use start position LINE,COL
+	if len(*flagLineColumn) > 0 {
+		positions := strings.Split(*flagLineColumn, ",")
+		if len(positions) == 2 {
+			lineNum, errPos1 := strconv.Atoi(positions[0])
+			colNum, errPos2 := strconv.Atoi(positions[1])
+			if errPos1 == nil && errPos2 == nil {
+				cursorStartX = colNum
+				cursorStartY = lineNum - 1
+				// Check to avoid line overflow
+				if cursorStartY > b.NumLines {
+					cursorStartY = b.NumLines - 1
+				} else if cursorStartY < 0 {
+					cursorStartY = 0
+				}
+				// Check to avoid column overflow
+				if cursorStartX > len(b.Line(cursorStartY)) {
+					cursorStartX = len(b.Line(cursorStartY))
+				} else if cursorStartX < 0 {
+					cursorStartX = 0
+				}
+			}
+		}
+	}
 	b.Cursor = Cursor{
 		Loc: Loc{
-			X: 0,
-			Y: 0,
+			X: cursorStartX,
+			Y: cursorStartY,
 		},
 		buf: b,
 	}

cmd/micro/micro.go

@@ -87,6 +87,13 @@ func LoadInput() []*Buffer {
 		// We go through each file and load it
 		for i := 1; i < len(os.Args); i++ {
 			filename = os.Args[i]
+
+			// Need to skip arguments that are not filenames
+			if filename == "-cursor" {
+				i++ // also skip the LINE,COL for -cursor
+				continue
+			}
+
 			// Check that the file exists
 			if _, e := os.Stat(filename); e == nil {
 				// If it exists we load it into a buffer
@@ -197,6 +204,9 @@ func RedrawAll() {
 // Passing -version as a flag will have micro print out the version number
 var flagVersion = flag.Bool("version", false, "Show the version number")
 
+// Passing -cursor LINE,COL will start the cursor at position LINE,COL
+var flagLineColumn = flag.String("cursor", "", "Start the cursor at position `LINE,COL`")
+
 func main() {
 	flag.Parse()
 	if *flagVersion {