From f016b99e0897074e59c88ac0d473e6c4692b4b20 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?J=C3=A9r=C3=B4me=20BOULMIER?= <jerome.boulmier@outlook.fr>
Date: Wed, 6 May 2020 22:28:05 +0200
Subject: [PATCH] Redirect process output to dev null

---
 include/utils/process.hpp |  2 ++
 src/utils/command.cpp     |  1 +
 src/utils/process.cpp     | 19 +++++++++++++++++--
 3 files changed, 20 insertions(+), 2 deletions(-)

diff --git a/include/utils/process.hpp b/include/utils/process.hpp
index 8210ac49..c5d91c01 100644
--- a/include/utils/process.hpp
+++ b/include/utils/process.hpp
@@ -8,6 +8,8 @@ namespace process_util {
   bool in_parent_process(pid_t pid);
   bool in_forked_process(pid_t pid);
 
+  void redirect_process_output_to_dev_null();
+
   void exec(char* cmd, char** args);
   void exec_sh(const char* cmd);
 
diff --git a/src/utils/command.cpp b/src/utils/command.cpp
index 1d08ae4b..ef44c0c5 100644
--- a/src/utils/command.cpp
+++ b/src/utils/command.cpp
@@ -37,6 +37,7 @@ int command<output_policy::IGNORED>::exec(bool wait_for_completion) {
 
   if (process_util::in_forked_process(m_forkpid)) {
     setpgid(m_forkpid, 0);
+    process_util::redirect_process_output_to_dev_null();
     process_util::exec_sh(m_cmd.c_str());
   } else {
     if (wait_for_completion) {
diff --git a/src/utils/process.cpp b/src/utils/process.cpp
index b11541de..79b1bce0 100644
--- a/src/utils/process.cpp
+++ b/src/utils/process.cpp
@@ -1,9 +1,11 @@
+#include "utils/process.hpp"
+
+#include <fcntl.h>
 #include <sys/wait.h>
 #include <unistd.h>
 
 #include "errors.hpp"
 #include "utils/env.hpp"
-#include "utils/process.hpp"
 #include "utils/string.hpp"
 
 POLYBAR_NS
@@ -23,6 +25,19 @@ namespace process_util {
     return pid == 0;
   }
 
+  void redirect_process_output_to_dev_null() {
+    auto redirect = [](int fd_to_redirect) {
+      int fd = open("/dev/null", O_WRONLY);
+      if (fd < 0 || dup2(fd, fd_to_redirect) < 0) {
+        throw system_error("Failed to redirect process output");
+      }
+      close(fd);
+    };
+
+    redirect(STDOUT_FILENO);
+    redirect(STDERR_FILENO);
+  }
+
   /**
    * Execute command
    */
@@ -105,6 +120,6 @@ namespace process_util {
   bool notify_childprocess() {
     return wait_for_completion_nohang() > 0;
   }
-}
+}  // namespace process_util
 
 POLYBAR_NS_END