refactor and and support for init from argv

include/spdlog/cfg/argv_loader.h

@@ -0,0 +1,47 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+#include <spdlog/cfg/text_loader.h>
+#include <spdlog/details/os.h>
+
+//
+// Init levels and patterns from env variables SPDLOG_LEVEL
+// Inspired from Rust's "env_logger" crate (https://crates.io/crates/env_logger).
+// Note - fallback to "info" level on unrecognized levels
+//
+// Examples:
+//
+// set global level to debug:
+// export SPDLOG_LEVEL=debug
+//
+// turn off all logging except for logger1:
+// export SPDLOG_LEVEL="off,logger1=debug"
+//
+// turn off all logging except for logger1 and logger2:
+// export SPDLOG_LEVEL="off,logger1=debug,logger2=info"
+
+namespace spdlog {
+namespace cfg {
+// search for SPDLOG_LEVEL= in the args and use it to init the levels
+void init_from_argv(int args, char *argv[])
+{
+    if (args < 2)
+    {
+        return;
+    }
+    const std::string spdlog_level_prefix = "SPDLOG_LEVEL=";
+    for (int i = 0; i < args; i++)
+    {
+        std::string arg = argv[i];
+        if (arg.find(spdlog_level_prefix) == 0)
+        {
+            auto cfg_string = arg.substr(spdlog_level_prefix.size());
+            auto levels = text_loader::load_levels(cfg_string);
+            spdlog::details::registry::instance().set_levels(levels);
+            return;
+        }
+    }
+}
+} // namespace cfg
+} // namespace spdlog

include/spdlog/cfg/env.h

@@ -2,10 +2,8 @@
 // Distributed under the MIT License (http://opensource.org/licenses/MIT)
 
 #pragma once
-
-#include <spdlog/common.h>
-#include <string>
-#include <unordered_map>
+#include <spdlog/cfg/text_loader.h>
+#include <spdlog/details/os.h>
 
 //
 // Init levels and patterns from env variables SPDLOG_LEVEL
@@ -24,11 +22,12 @@
 // export SPDLOG_LEVEL="off,logger1=debug,logger2=info"
 
 namespace spdlog {
-namespace env {
-void load_levels();
-} // namespace env
+namespace cfg {
+void init_from_env()
+{
+    auto cfg = details::os::getenv("SPDLOG_LEVEL");
+    auto levels = text_loader::load_levels(cfg);
+    spdlog::details::registry::instance().set_levels(levels);
+}
+} // namespace cfg
 } // namespace spdlog
-
-#ifdef SPDLOG_HEADER_ONLY
-#include "env-inl.h"
-#endif // SPDLOG_HEADER_ONLY

include/spdlog/cfg/text_loader-inl.h

@@ -4,7 +4,7 @@
 #pragma once
 
 #ifndef SPDLOG_HEADER_ONLY
-#include <spdlog/cfg/env.h>
+#include <spdlog/cfg/text_loader.h>
 #endif
 
 #include <spdlog/spdlog.h>
@@ -16,7 +16,8 @@
 #include <sstream>
 
 namespace spdlog {
-namespace env {
+namespace cfg {
+namespace text_loader {
 
 using name_val_pair = std::pair<std::string, std::string>;
 
@@ -106,11 +107,11 @@ inline details::registry::logger_levels extract_levels_(const std::string &input
     return rv;
 }
 
-SPDLOG_INLINE void load_levels()
+SPDLOG_INLINE details::registry::logger_levels load_levels(const std::string &cfg)
 {
-    auto levels = extract_levels_(details::os::getenv("SPDLOG_LEVEL"));
-    spdlog::details::registry::instance().set_levels(levels);
+    return extract_levels_(cfg);
 }
 
-} // namespace env
+} // namespace text_loader
+} // namespace cfg
 } // namespace spdlog

include/spdlog/cfg/text_loader.h

@@ -0,0 +1,37 @@
+// Copyright(c) 2015-present, Gabi Melman & spdlog contributors.
+// Distributed under the MIT License (http://opensource.org/licenses/MIT)
+
+#pragma once
+
+#include <spdlog/common.h>
+#include <string>
+#include <unordered_map>
+
+//
+// Init levels and patterns from env variables SPDLOG_LEVEL
+// Inspired from Rust's "env_logger" crate (https://crates.io/crates/env_logger).
+// Note - fallback to "info" level on unrecognized levels
+//
+// Examples:
+//
+// set global level to debug:
+// export SPDLOG_LEVEL=debug
+//
+// turn off all logging except for logger1:
+// export SPDLOG_LEVEL="off,logger1=debug"
+//
+// turn off all logging except for logger1 and logger2:
+// export SPDLOG_LEVEL="off,logger1=debug,logger2=info"
+
+namespace spdlog {
+namespace cfg {
+namespace text_loader {
+details::registry::logger_levels load_levels(const std::string &cfg);
+}
+
+} // namespace cfg
+} // namespace spdlog
+
+#ifdef SPDLOG_HEADER_ONLY
+#include "text_loader-inl.h"
+#endif // SPDLOG_HEADER_ONLY