add CLI Command::get_arg_maybe()

2 files changed, 15 insertions, 0 deletions

diff --git a/src/cli/cli.cpp b/src/cli/cli.cpp
index e58f1a68d..8cf2de99e 100644
--- a/src/cli/cli.cpp
+++ b/src/cli/cli.cpp
@@ -128,6 +128,15 @@ std::string Command::get_arg_or(const std::string& opt_name, const std::string&
    return m_args->get_arg_or(opt_name, otherwise);
    }
 
+std::optional<std::string> Command::get_arg_maybe(const std::string& opt_name) const
+   {
+   auto arg = m_args->get_arg(opt_name);
+   if(arg.empty())
+      return std::nullopt;
+   else
+      return arg;
+   }
+
 size_t Command::get_arg_sz(const std::string& opt_name) const
    {
    return m_args->get_arg_sz(opt_name);
diff --git a/src/cli/cli.h b/src/cli/cli.h
index b7f81277d..2f2080ea9 100644
--- a/src/cli/cli.h
+++ b/src/cli/cli.h
@@ -10,6 +10,7 @@
 #include <botan/build.h>
 #include <functional>
 #include <ostream>
+#include <optional>
 #include <map>
 #include <memory>
 #include <string>
@@ -146,6 +147,11 @@ class Command
       */
       std::string get_arg_or(const std::string& opt_name, const std::string& otherwise) const;
 
+      /*
+      * Like get_arg() but if the argument was not specified or is empty, returns std::nullopt
+      */
+      std::optional<std::string> get_arg_maybe(const std::string& opt_name) const;
+
       size_t get_arg_sz(const std::string& opt_name) const;
 
       uint16_t get_arg_u16(const std::string& opt_name) const;