Open first line of a file

editor/editor.go

@@ -1,6 +1,9 @@
 package editor
 
 import (
+	"bufio"
+	"log"
+	"os"
 	"timshome.page/gilo/terminal"
 )
 
@@ -23,12 +26,28 @@ func New() *editor {
 	screen := terminal.Size()
 	cursor := &cursor { 0, 0 }
 	var rows []*row
+	rows = append(rows, NewRow(""))
 
 	return &editor{screen, cursor, rows }
 }
 
-func (e *editor) Open() {
-	e.rows = append(e.rows, NewRow("Hello, world!"))
+func (e *editor) Open(filename string) {
+	file, err := os.Open(filename)
+	if err != nil {
+		log.Fatalf("failed to open file")
+	}
+	defer file.Close()
+
+	scanner := bufio.NewScanner(file)
+	scanner.Split(bufio.ScanLines)
+
+	var lines []string
+
+	for scanner.Scan() {
+		lines = append(lines, scanner.Text())
+	}
+
+	e.rows = append(e.rows, NewRow(lines[0]))
 }
 
 func (e *editor) ProcessKeypress() bool {

gilo.go

@@ -3,6 +3,7 @@ package main
 import (
 	"fmt"
 	"golang.org/x/term"
+	"os"
 	"timshome.page/gilo/editor"
 	"timshome.page/gilo/terminal"
 )
@@ -22,7 +23,11 @@ func main() {
 	defer cleanup(oldState)
 
 	e := editor.New()
-	e.Open()
+
+	// If there is an argument passed, open it as a file to edit
+	if len(os.Args) >= 2 && os.Args[1] != "" {
+		e.Open(os.Args[1])
+	}
 
 	// The input loop
 	for {