From a5585150f0ff8d27ddd22792f521f1374a3eedd8 Mon Sep 17 00:00:00 2001
From: Bent Bisballe Nyeng <deva@aasimon.org>
Date: Fri, 20 Jan 2023 08:37:29 +0100
Subject: Add env to execute function.

---
 src/execute.cc | 82 ++++++++++++++++++++++++++++++++++++++++++++--------------
 1 file changed, 63 insertions(+), 19 deletions(-)

(limited to 'src/execute.cc')

diff --git a/src/execute.cc b/src/execute.cc
index 20a4a02..b4013d0 100644
--- a/src/execute.cc
+++ b/src/execute.cc
@@ -20,6 +20,28 @@ https://stackoverflow.com/questions/4259629/what-is-the-difference-between-fork-
 
 namespace
 {
+class Env
+	: public std::vector<char*>
+{
+public:
+	Env(const std::vector<std::string>& args)
+	{
+		for(const auto& arg : args)
+		{
+			push_back(strdup(arg.data()));
+		}
+		push_back(nullptr);
+	}
+
+	~Env()
+	{
+		for(auto ptr : *this)
+		{
+			free(ptr);
+		}
+	}
+};
+
 int parent_waitpid(pid_t pid)
 {
 	int status;
@@ -33,8 +55,11 @@ int parent_waitpid(pid_t pid)
 }
 } // namespace ::
 
+extern char **environ; // see 'man environ'
+
 int execute(const std::string& command,
             const std::vector<std::string>& args,
+            const std::map<std::string, std::string>& env,
             bool verbose)
 {
 	std::vector<const char*> argv;
@@ -45,22 +70,22 @@ int execute(const std::string& command,
 	}
 	argv.push_back(nullptr);
 
-	if(verbose)
+	std::string cmd;
+	for(const auto& arg : argv)
 	{
-		std::string cmd;
-		for(const auto& arg : argv)
+		if(arg == nullptr)
 		{
-			if(arg == nullptr)
-			{
-				break;
-			}
-			if(!cmd.empty())
-			{
-				cmd += " ";
-			}
-			cmd += arg;
+			break;
 		}
+		if(!cmd.empty())
+		{
+			cmd += " ";
+		}
+		cmd += arg;
+	}
 
+	if(verbose)
+	{
 		std::cout << cmd << std::endl;
 	}
 
@@ -68,23 +93,42 @@ int execute(const std::string& command,
 	auto pid = vfork();
 	if(pid == 0)
 	{
-		execv(command.data(), (char**)argv.data());
+		std::vector<std::string> venv;
+		for(const auto& [key, value] : env)
+		{
+			venv.push_back(key + "=" + value);
+		}
+
+		for(auto current = environ; *current; ++current)
+		{
+			venv.push_back(*current);
+		}
+
+		Env penv(venv);
+		execve(command.data(), (char**)argv.data(), penv.data());
 		std::cout << "Could not execute " << command << ": " <<
 			strerror(errno) << "\n";
-		_exit(1); // execv only returns if an error occurred
+		_exit(1); // execve only returns if an error occurred
 	}
-	auto ret = parent_waitpid(pid);
+	return parent_waitpid(pid);
 #elif 0
 	pid_t pid;
+	std::vector<std::string> venv;
+	for(const auto& [key, value] : env)
+	{
+		venv.push_back(key + "=" + value);
+	}
+	Env penv(venv);
 	if(posix_spawn(&pid, command.data(), nullptr, nullptr,
-	               (char**)argv.data(), nullptr))
+	               (char**)argv.data(), penv.data()))
 	{
 		return 1;
 	}
-	auto ret = parent_waitpid(pid);
+	return parent_waitpid(pid);
 #else
-	auto ret = system(cmd.data());
+	(void)parent_waitpid;
+	return system(cmd.data());
 #endif
 
-	return ret;
+	return 1;
 }
-- 
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