all tasks

Task/Take-notes-on-the-command-line/Go/take-notes-on-the-command-line.go

@@ -0,0 +1,46 @@
+package main
+
+import (
+    "fmt"
+    "io"
+    "os"
+    "strings"
+    "time"
+)
+
+const fn = "NOTES.TXT"
+
+func main() {
+    if len(os.Args) == 1 {
+        f, err := os.Open(fn)
+        if err != nil {
+            // don't report "file does not exist" as an error, but
+            // if it seems to be there but just can't be opened for
+            // some reason, print original error from open attempt.
+            if _, statErr := os.Stat(fn); statErr == nil {
+                fmt.Println(err)
+            }
+            return
+        }
+        if _, err = io.Copy(os.Stdout, f); err != nil {
+            fmt.Println(err)
+        }
+        if cErr := f.Close(); err == nil && cErr != nil {
+            fmt.Println(err)
+        }
+        return
+    }
+    f, err := os.OpenFile(fn, os.O_RDWR|os.O_APPEND|os.O_CREATE, 0666)
+    if err != nil {
+        fmt.Println(err)
+        return
+    }
+    _, err = fmt.Fprint(f, time.Now().Format(time.RFC1123),
+        "\n\t", strings.Join(os.Args[1:], " "), "\n")
+    if err != nil {
+        fmt.Println(err)
+    }
+    if cErr := f.Close(); err == nil && cErr != nil {
+        fmt.Println(cErr)
+    }
+}