goutils

commit 31ab1e2879765fc05589d10e2b68603275b269df
Author: Matsuda Kenji <info@mtkn.jp>
Date:   Tue, 17 Sep 2024 15:25:42 +0900

first commit

Diffstat:
A
cat/main.go
 | 
45
+++++++++++++++++++++++++++++++++++++++++++++
A
false/main.go
 | 
5
+++++
A
go.mod
 | 
3
+++
A
true/main.go
 | 
7
+++++++

4 files changed, 60 insertions(+), 0 deletions(-)
diff --git a/cat/main.go b/cat/main.go
@@ -0,0 +1,45 @@
+package main
+
+import (
+	"fmt"
+	"io"
+	"os"
+)
+
+func main() {
+	if len(os.Args) == 1 {
+		cat(os.Stdin)
+		return
+	}
+	for _, fname := range os.Args[1:] {
+		f, err := os.Open(fname)
+		if err != nil {
+			fmt.Fprintf(os.Stderr, "cat: %v\n", err)
+			os.Exit(1)
+		}
+		if err := cat(f); err != nil {
+			fmt.Fprintf(os.Stderr, "cat: %v\n", err)
+			f.Close()
+			os.Exit(1)
+		}
+		f.Close()
+	}
+}
+
+func cat(f *os.File) error {
+	buf := make([]byte, 8192)
+	for {
+		n, err := f.Read(buf)
+		if n == 0 && err == io.EOF {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		_, err = os.Stdout.Write(buf[:n])
+		if err != nil {
+			return err
+		}
+	}
+	return nil
+}
diff --git a/false/main.go b/false/main.go
@@ -0,0 +1,5 @@
+package main
+
+import "os"
+
+func main() { os.Exit(1) }
diff --git a/go.mod b/go.mod
@@ -0,0 +1,3 @@
+module git.mtkn.jp/goutils
+
+go 1.23.0
diff --git a/true/main.go b/true/main.go
@@ -0,0 +1,7 @@
+package main
+
+import "os"
+
+func main() {
+	os.Exit(0)
+}