add an initial hacky svn-runner capturing subversion standard output

src/SvnRunner.cc

@@ -0,0 +1,73 @@
+#include "SvnRunner.h"
+#include <stdio.h>
+#include <unistd.h>
+#include <stdlib.h>
+#include <sys/types.h>
+#include <sys/wait.h>
+
+void SvnRunner::exec_svn(std::vector<std::string> arguments)
+{
+    int fd[2];
+    int pipe_rc = pipe(fd);
+    if (pipe_rc == -1)
+    {
+        perror("pipe");
+        return;
+    }
+    pid_t pid = fork();
+    if (pid == -1)
+    {
+        perror("fork");
+        return;
+    }
+    if (pid == 0)
+    {
+        close(fd[0]);
+        int dup2_rc = dup2(fd[1], STDOUT_FILENO);
+        if (dup2_rc == -1)
+        {
+            perror("dup2");
+            return;
+        }
+        char const * argv[arguments.size() + 2];
+        argv[0] = "svn";
+        argv[arguments.size() + 1] = NULL;
+        for (unsigned int i = 0; i < arguments.size(); i++)
+        {
+            argv[i + 1] = arguments[i].c_str();
+        }
+        int exec_rc = execvp("/usr/bin/svn", (char **)argv);
+        if (exec_rc == -1)
+        {
+            perror("exec");
+            exit(1);
+        }
+    }
+    else
+    {
+        close(fd[1]);
+        size_t n = 100;
+        char * line = (char *)malloc(n);
+        FILE * in = fdopen(fd[0], "r");
+        ssize_t getline_rc;
+        for (;;)
+        {
+            getline_rc = getline(&line, &n, in);
+            if (getline_rc == -1)
+                break;
+            printf("Got >%s<\n", line);
+        }
+        fclose(in);
+        int status;
+        int waitpid_rc = waitpid(pid, &status, 0);
+        if (waitpid_rc == -1)
+        {
+            perror("waitpid");
+        }
+        if (WEXITSTATUS(status) != 0)
+        {
+            fprintf(stderr, "Warning: svn exit status = %d\n", WEXITSTATUS(status));
+        }
+        free(line);
+    }
+}

src/SvnRunner.h

@@ -0,0 +1,8 @@
+#include <string>
+#include <vector>
+
+class SvnRunner
+{
+public:
+    static void exec_svn(std::vector<std::string> arguments);
+};

src/svi.cc

@@ -1,8 +1,10 @@
 #include <iostream>
+#include "SvnRunner.h"
 
 using namespace std;
 
 int main(int argc, char * argv[])
 {
     cout << "Hello there." << endl;
+    SvnRunner::exec_svn({"ls"});
 }