Initial commit

internal/shutils/handlers/exec.go

@@ -0,0 +1,63 @@
+/*
+ * LURE - Linux User REpository
+ * Copyright (C) 2023 Elara Musayelyan
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package handlers
+
+import (
+	"context"
+	"fmt"
+	"time"
+
+	"mvdan.cc/sh/v3/interp"
+)
+
+func InsufficientArgsError(cmd string, exp, got int) error {
+	argsWord := "arguments"
+	if exp == 1 {
+		argsWord = "argument"
+	}
+
+	return fmt.Errorf("%s: command requires at least %d %s, got %d", cmd, exp, argsWord, got)
+}
+
+type ExecFunc func(hc interp.HandlerContext, name string, args []string) error
+
+type ExecFuncs map[string]ExecFunc
+
+// ExecHandler returns a new ExecHandlerFunc that falls back to fallback
+// if the command cannot be found in the map. If fallback is nil, the default
+// handler is used.
+func (ef ExecFuncs) ExecHandler(fallback interp.ExecHandlerFunc) interp.ExecHandlerFunc {
+	return func(ctx context.Context, args []string) error {
+		name := args[0]
+
+		if fn, ok := ef[name]; ok {
+			hctx := interp.HandlerCtx(ctx)
+			if len(args) > 1 {
+				return fn(hctx, args[0], args[1:])
+			} else {
+				return fn(hctx, args[0], nil)
+			}
+		}
+
+		if fallback == nil {
+			fallback = interp.DefaultExecHandler(2 * time.Second)
+		}
+		return fallback(ctx, args)
+	}
+}