initial commit

tplCmd/funcs_templatecmd.go

@@ -0,0 +1,73 @@
+package tplCmd
+
+import (
+	`bytes`
+	`os`
+	`os/exec`
+	`text/template`
+)
+
+// ToCmd returns an (os/)exec.Cmd from a TemplateCmd. t should be a tunnelbroker.FetchedTunnel, generally.
+func (c *TemplateCmd) ToCmd(t any) (cmd *exec.Cmd, err error) {
+
+	var progName string
+	var envs []string
+	var tpl *template.Template
+	var args []string
+	var buf *bytes.Buffer = new(bytes.Buffer)
+
+	buf.Reset()
+	if tpl, err = template.New("").Parse(c.Program); err != nil {
+		return
+	}
+	if err = tpl.Execute(buf, t); err != nil {
+		return
+	}
+	progName = buf.String()
+
+	if c.Args != nil && len(c.Args) > 0 {
+		args = make([]string, len(c.Args))
+		for idx, arg := range c.Args {
+			buf.Reset()
+			if tpl, err = template.New("").Parse(arg); err != nil {
+				return
+			}
+			if err = tpl.Execute(buf, t); err != nil {
+				return
+			}
+			args[idx] = buf.String()
+		}
+
+	}
+
+	if c.EnvVars != nil && len(c.EnvVars) > 0 {
+		envs = make([]string, len(c.EnvVars))
+		for idx, env := range c.EnvVars {
+			buf.Reset()
+			if tpl, err = template.New("").Parse(env); err != nil {
+				return
+			}
+			if err = tpl.Execute(buf, t); err != nil {
+				return
+			}
+			envs[idx] = buf.String()
+		}
+	}
+	if !c.IsolateEnv {
+		if envs != nil && len(envs) > 0 {
+			envs = append(os.Environ(), envs...)
+		} else {
+			envs = os.Environ()
+		}
+	}
+
+	if args != nil && len(args) > 0 {
+		cmd = exec.Command(progName, args...)
+	} else {
+		cmd = exec.Command(progName)
+	}
+
+	cmd.Env = envs
+
+	return
+}