Mercurial > hg > repoheat / changeset

--- a/src/Makefile	Tue Jan 21 18:09:14 2025 +0100
+++ b/src/Makefile	Tue Jan 21 18:25:59 2025 +0100
@@ -23,7 +23,7 @@
 
 include ../config.mk
 
-SRC=main.cpp
+SRC=main.cpp process.cpp
 OBJ=$(SRC:%.cpp=../build/%.o)
 OUTPUT=../build/fallusmeter
 
@@ -44,3 +44,7 @@
 	@echo "Compiling $<"
 	$(CXX) -o $@ $(CXXFLAGS)  -c $<
 
+../build/process.o: process.cpp process.h
+	@echo "Compiling $<"
+	$(CXX) -o $@ $(CXXFLAGS)  -c $<
+

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/process.cpp	Tue Jan 21 18:25:59 2025 +0100
@@ -0,0 +1,104 @@
+/* Copyright 2025 Mike Becker. All rights reserved.
+*
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include "process.h"
+
+#include <cstdio>
+#include <cstdlib>
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/wait.h>
+
+using namespace fm;
+
+process::process(std::string path): m_path(std::move(path)) {
+}
+
+bool process::exec(std::vector<std::string> args) {
+    // fd-pair for the pipe
+    int pipefd[2];
+
+    if (pipe(pipefd)) {
+        perror("pipe");
+        return false;
+    }
+
+    pid_t pid = fork();
+    if (pid == 0) {
+        // connect the pipe and close the end we don't use
+        if (dup2(pipefd[1], STDOUT_FILENO) == -1) {
+            perror("pipe");
+            exit(EXIT_FAILURE);
+        }
+        close(pipefd[0]);
+
+        // create the execv argument list
+        char *argv[args.size() + 2] = {};
+        auto slash = m_path.find_last_of('/');
+        if (slash == std::string::npos) {
+            argv[0] = m_path.data();
+        } else {
+            argv[0] = m_path.data() + slash + 1;
+        }
+        unsigned i = 0;
+        for (auto&& arg : args) {
+            argv[++i] = arg.data();
+        }
+        argv[args.size() + 1] = nullptr;
+
+        // execute the child program
+        if (execv(m_path.c_str(), argv)) {
+            perror("execl");
+            exit(EXIT_FAILURE);
+        }
+        return true; // unreachable, but the compiler doesn't know that
+    } else if (pid > 0) {
+        // close the end of the pipe we don't use
+        close(pipefd[1]);
+
+        // read all the output
+        char buf[64];
+        ssize_t r;
+        while ((r = read(pipefd[0], buf, sizeof(buf))) > 0) {
+            m_output.append(buf, r);
+        }
+        if (r < 0) {
+            perror("read");
+        }
+        close(pipefd[0]);
+
+        // wait for the process to completely finish
+        int status = -1;
+        waitpid(pid, &status, 0);
+
+        return status == 0;
+    } else {
+        perror("fork");
+        return false;
+    }
+}
+
+const std::string &process::output() const {
+    return m_output;
+}

--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/process.h	Tue Jan 21 18:25:59 2025 +0100
@@ -0,0 +1,46 @@
+/* Copyright 2025 Mike Becker. All rights reserved.
+*
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ *
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+ * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+ * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+ * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+ * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#ifndef PROCESS_H
+#define PROCESS_H
+
+#include <string>
+#include <vector>
+
+namespace fm {
+
+class process {
+    std::string m_path;
+    std::string m_output;
+public:
+    explicit process(std::string path);
+    ~process() = default;
+
+    [[nodiscard]] bool exec(std::vector<std::string> args);
+    [[nodiscard]] const std::string &output() const;
+};
+
+}
+
+#endif //PROCESS_H