Refactored popen/pclose into custom implementation and added c++ wrappers

Author: mikucionisaau

source/matplot/backend/gnuplot.cpp

@@ -70,15 +70,16 @@ namespace matplot::backend {
         }
 
         // Open the gnuplot pipe_
+        int perr;
         if constexpr (windows_should_persist_by_default) {
-            pipe_ = POPEN("gnuplot --persist", "w");
+            perr = popen2("gnuplot --persist", "w", &pipe_);
         } else {
-            pipe_ = POPEN("gnuplot", "w");
+            perr = popen2("gnuplot", "w", &pipe_);
         }
 
         // Check if everything is OK
-        if (!pipe_) {
-            std::cerr << "Opening the gnuplot pipe_ failed!" << std::endl;
+        if (perr != 0) {
+            std::cerr << "Opening the gnuplot pipe_ failed: " std::strerror(perr) << std::endl;
             std::cerr
                 << "Please install gnuplot 5.2.6+: http://www.gnuplot.info"
                 << std::endl;
@@ -97,8 +98,8 @@ namespace matplot::backend {
         flush_commands();
         run_command("exit");
         flush_commands();
-        if (pipe_) {
-            PCLOSE(pipe_);
+        if (pipe_.file != nullptr) {
+            pclose2(&pipe_);
         }
     }
 
@@ -281,8 +282,7 @@ namespace matplot::backend {
         if constexpr (dont_let_it_close_too_fast) {
             last_flush_ = std::chrono::high_resolution_clock::now();
         }
-        fputs("\n", pipe_);
-        fflush(pipe_);
+        proc_flush(&pipe_, "\n");
         if constexpr (trace_commands) {
             std::cout << "\n\n\n\n" << std::endl;
         }
@@ -294,19 +294,19 @@ namespace matplot::backend {
     }
 
     void gnuplot::run_command(const std::string &command) {
-        if (!pipe_) {
+        if (pipe_.file != nullptr) {
             return;
         }
-        size_t pipe_capacity = gnuplot_pipe_capacity(pipe_);
+        size_t pipe_capacity = gnuplot_pipe_capacity(pipe_.file);
         if (command.size() + bytes_in_pipe_ > pipe_capacity) {
             flush_commands();
             bytes_in_pipe_ = 0;
         }
         if (!command.empty()) {
-            fputs(command.c_str(), pipe_);
+            proc_write(&pipe_, command);
         }
-        // fputs("; ", pipe_);
-        fputs("\n", pipe_);
+        // proc_write(&pipe_, "; ");
+        proc_write(&pipe_, "\n");
         bytes_in_pipe_ += command.size();
         if constexpr (trace_commands) {
             std::cout << command << std::endl;

source/matplot/backend/gnuplot.h

@@ -7,6 +7,7 @@
 
 #include <matplot/detail/config.h>
 #include <matplot/backend/backend_interface.h>
+#include <matplot/util/popen.h>
 #include <array>
 #include <chrono>
 #include <tuple>
@@ -115,8 +116,8 @@ namespace matplot::backend {
         }
 
       private:
-        // Pipe to gnuplot process
-        FILE *pipe_;
+        // Process pipe to gnuplot
+        ProcPipe pipe_;
 
         // How many bytes we put in the pipe
         size_t bytes_in_pipe_{0};

source/matplot/util/common.cpp

@@ -50,26 +50,8 @@ namespace matplot {
                iequals(str, "no");
     }
 
-    struct pipe_deleter {
-        int operator()(FILE* pipe) const {
-            if (int status = PCLOSE(pipe); status != -1)
-                return status;
-            throw std::system_error{errno, std::system_category(), "pclose"};
-        }
-    };
-
     std::string run_and_get_output(const std::string &cmd) {
-        std::unique_ptr<FILE, pipe_deleter> pipe(POPEN(cmd.c_str(), "r"));
-        if (!pipe) {
-            throw std::system_error{errno, std::system_category(), cmd};
-        }
-        std::array<char, 128> buffer{};
-        std::string result;
-        while (fgets(buffer.data(), static_cast<int>(buffer.size()),
-                     pipe.get()) != nullptr) {
-            result += buffer.data();
-        }
-        return result;
+        return shell_read(cmd);
     }
 
     std::string escape(std::string_view label) {