initial commit

cli.go

@@ -0,0 +1,41 @@
+// Command-line arguments parsing and formatted console output.
+package cli
+
+import (
+	"os"
+	"sync"
+)
+
+// Terminal capabilites.
+type TerminalInfo struct {
+	IsTTY         bool
+	SupportsColor bool
+	Width         int
+}
+
+// Returns cached TerminalInfo for os.Stdin.
+var GetStdinInfo = sync.OnceValue(func() TerminalInfo {
+	return GetTerminalInfo(os.Stdin)
+})
+
+// Returns cached TerminalInfo for os.Stdout.
+var GetStdoutInfo = sync.OnceValue(func() TerminalInfo {
+	return GetTerminalInfo(os.Stdout)
+})
+
+// Returns cached TerminalInfo for os.Stderr.
+var GetStderrInfo = sync.OnceValue(func() TerminalInfo {
+	return GetTerminalInfo(os.Stderr)
+})
+
+type ExitReason uint8
+
+const (
+	UserError     ExitReason = 1
+	BadUsage                 = 2
+	InternalError            = 3
+)
+
+func ShortCircuit() {
+	os.Exit(0)
+}