menu for dmenu

menu

// This program gathers and pipes a user-created menu into
// dmenu and allows the user to pick and execute apps:
//
// dmenurc file -> menu -> dmenu -> run chosen app :)
//
// NOTE: dmenu MUST be installed for this program to work!
//
// The goals of this project:
//
//	1. < 100 lines code
//	2. Simple & elegant coding
//	3. Fast & efficient execution.
//
//		"Do one thing,
//		 and do it well."
//
//		—Linux Credo
//
// Compile with:
// $ g++ -O2 -Wall menu.cpp -o menu
//
// Make a 9menurc style file in ~/.config/dmenurc with
// application name, a colon, and the application command.
// If no colon is entered, the command will be shown and
// run as its name. Below, 'midori', will run as 'midori'.
//
// Example:
//
// midori
// htop:st -e htop
// surf:surf
// mutt:mutt
//
//
// Run with:
// $ menu
//

#include<experimental/string_view>
#include<iostream>
#include<string>
#include<fstream>
#include<regex>

using namespace std;

std::string exec(const char* cmd) {

        std::array<char, 128> buffer;
        std::string result;
        std::shared_ptr<FILE> pipe(popen(cmd, "r"), pclose);
        if (!pipe) throw std::runtime_error("popen() failed!");

                while (!feof(pipe.get()))
                        if (fgets(buffer.data(), 128, pipe.get()) != nullptr){
                                result += buffer.data();
        }

	// Get ride of extra return carriage
        return result.substr(0, result.length() - 1);
}


std::string appSearch(const std::string & searchedApp, const bool & search)
{
	std::string s;
	std::string appName;
	std::string appCommand;
        std::string apps = "";

	std::size_t colonPos;

        ifstream myFile("/home/user/.config/dmenurc");

	while (getline (myFile, s))
	{

		colonPos = s.find(":");			// A colon divides entry name from command
		if (colonPos!=std::string::npos)
	        {
			appName = s.substr(0, colonPos);
			appCommand = s.substr(colonPos + 1);
		}else					// App has no colon to delimit command. Run as name.
			appName = appCommand = s;

		apps += appName + "\\n";

		// We found our app, and we have our command to run, so exit and run it!
		if (!search && appName == searchedApp)
			return appCommand;
	}

	myFile.close();

	// Nothing found, so just send back the parameters entered to be used as a command
	if (!search && searchedApp != "")
		return searchedApp;
	else if (!search && searchedApp == "")	// User didn't select an app to run
		return "";

	// Remove last return carriage from app list
	return apps.substr(0, apps.length() - 2);
}


int main(int argc, char* argv[])
{

	std::string sysStrCmd	= "";
        const char * sysCharCmd;

	// Prepare dmenu applist; true bool indicates search, and false, run command
	sysStrCmd = "echo \"" +  appSearch("", true) + "\" | dmenu -b -f";

	// Now execute the above command parameters. Save the resulting command to sysStrCmd
	if ((sysStrCmd = appSearch(exec(sysCharCmd = sysStrCmd.c_str()), false)) == "")
		return 0;

	system((sysCharCmd = sysStrCmd.c_str()));

	return 0;

}