Add GZ_CONSOLE_COLOR env variable to control terminal color output

README.md

@@ -61,6 +61,13 @@ See the [installation tutorial](https://gazebosim.org/api/common/5/install.html)
 
 Please refer to the [examples directory](https://github.com/gazebosim/gz-common/tree/main/examples).
 
+Console color output can be controlled with `GZ_CONSOLE_COLOR`:
+
+* `yes`: always emit ANSI color codes.
+* `no`: never emit ANSI color codes.
+
+Only `yes` and `no` are recognized. Other values are ignored with a warning.
+
 # Folder Structure
 
 Refer to the following table for information about important directories and files in this repository.

src/Console.cc

@@ -28,6 +28,34 @@
 using namespace gz;
 using namespace common;
 
+#define CONSOLE_COLOR_ON 1
+#define CONSOLE_COLOR_OFF 0
+
+static int consoleColorMode = CONSOLE_COLOR_ON;
+
+/////////////////////////////////////////////////
+static void UpdateConsoleColorMode()
+{
+  std::string consoleColor;
+  if (!env("GZ_CONSOLE_COLOR", consoleColor))
+    return;
+
+  const auto value = lowercase(trimmed(consoleColor));
+  if (value == "yes")
+  {
+    consoleColorMode = CONSOLE_COLOR_ON;
+  }
+  else if (value == "no")
+  {
+    consoleColorMode = CONSOLE_COLOR_OFF;
+  }
+  else
+  {
+    std::cerr << "Invalid value for GZ_CONSOLE_COLOR='" << consoleColor
+      << "'. Valid values are: yes, no." << std::endl;
+  }
+}
+
 
 FileLogger common::Console::log("");
 
@@ -156,7 +184,11 @@ int Logger::Buffer::sync()
       outstr.pop_back();
 
     std::stringstream ss;
-    ss << "\033[1;" << this->color << "m" << outstr << "\033[0m";
+    if (consoleColorMode == CONSOLE_COLOR_OFF)
+      ss << outstr;
+    else
+      ss << "\033[1;" << this->color << "m" << outstr << "\033[0m";
+
     if (lastNewLine)
       ss << std::endl;
 
@@ -190,7 +222,7 @@ int Logger::Buffer::sync()
 
     {
       std::lock_guard<std::mutex> lk(this->syncMutex);
-      if (vtProcessing)
+      if (vtProcessing && consoleColorMode != CONSOLE_COLOR_OFF)
         outStream << "\x1b[" << this->color << "m" << outstr << "\x1b[m";
       else
         outStream << outstr;
@@ -234,6 +266,8 @@ void FileLogger::Init(const std::string &_directory,
 {
   std::string logPath;
 
+  UpdateConsoleColorMode();
+
   if (_directory.empty() ||
 #ifndef _WIN32
     _directory[0] != '/'

src/Console_TEST.cc

@@ -549,3 +549,71 @@ TEST_F(Console_TEST, NoInitAndLogNoHome)
   // This should not throw
   gzlog << "this is a test" << std::endl;
 }
+
+/////////////////////////////////////////////////
+/// \brief Test Console color output with GZ_CONSOLE_COLOR=yes
+TEST_F(Console_TEST, ConsoleColorYes)
+{
+  common::Console::SetVerbosity(3);
+  EXPECT_TRUE(common::setenv("GZ_CONSOLE_COLOR", "yes"));
+
+  // Initialize 
+  auto path = common::uuid();
+  gzLogInit(path, "test.log");
+
+  // stdout to check for ANSI codes
+  testing::internal::CaptureStdout();
+  gzmsg << "color yes test" << std::endl;
+  std::string output = testing::internal::GetCapturedStdout();
+
+#ifndef _WIN32
+  // Check for ANSI escape sequence
+  EXPECT_TRUE(output.find("\033[") != std::string::npos);
+#endif
+
+  EXPECT_TRUE(common::unsetenv("GZ_CONSOLE_COLOR"));
+  common::Console::SetVerbosity(1);
+  gzLogClose();
+}
+
+/////////////////////////////////////////////////
+/// \brief Test Console color output with GZ_CONSOLE_COLOR=no
+TEST_F(Console_TEST, ConsoleColorNo)
+{
+  common::Console::SetVerbosity(3);
+  EXPECT_TRUE(common::setenv("GZ_CONSOLE_COLOR", "no"));
+
+  // Initialize 
+  auto path = common::uuid();
+  gzLogInit(path, "test.log");
+
+  // stdout to check for no ANSI codes
+  testing::internal::CaptureStdout();
+  gzmsg << "color no test" << std::endl;
+  std::string output = testing::internal::GetCapturedStdout();
+
+  // Check for no ANSI escape sequence
+  EXPECT_TRUE(output.find("\033[") == std::string::npos);
+
+  EXPECT_TRUE(common::unsetenv("GZ_CONSOLE_COLOR"));
+  common::Console::SetVerbosity(1);
+  gzLogClose();
+}
+
+/////////////////////////////////////////////////
+/// \brief Test invalid GZ_CONSOLE_COLOR value warning
+TEST_F(Console_TEST, ConsoleColorInvalid)
+{
+  EXPECT_TRUE(common::setenv("GZ_CONSOLE_COLOR", "maybe"));
+
+  // check stderr to check for warning message
+  testing::internal::CaptureStderr();
+  auto path = common::uuid();
+  gzLogInit(path, "test.log");
+  std::string output = testing::internal::GetCapturedStderr();
+
+  EXPECT_TRUE(output.find("Invalid value for GZ_CONSOLE_COLOR") != std::string::npos);
+
+  EXPECT_TRUE(common::unsetenv("GZ_CONSOLE_COLOR"));
+  gzLogClose();
+}