source/misc.cpp

   1 /* $Id$
   2
   3 This file is part of builder
   4 Copyright © 2006-2007 Mikko Rasa, Mikkosoft Productions
   5 Distributed under the LGPL
   6 */
   7
   8 #include <iostream>
   9 #include <sys/wait.h>
  10 #include "misc.h"
  11
  12 using namespace std;
  13 using namespace Msp;
  14
  15 /**
  16 Runs a command and returns its output as a string.  The exit status of the
  17 command is lost.
  18 */
  19 string run_command(const StringList &argv)
  20 {
  21         int pfd[2];
  22         pipe(pfd);
  23
  24         string result;
  25
  26         pid_t pid=fork();
  27         if(pid==0)
  28         {
  29                 char *argv_[argv.size()+1];
  30
  31                 unsigned j=0;
  32                 for(StringList::const_iterator i=argv.begin(); i!=argv.end(); ++i)
  33                         argv_[j++]=strdup(i->c_str());
  34                 argv_[j]=0;
  35
  36                 close(pfd[0]);
  37                 dup2(pfd[1], 1);
  38                 dup2(pfd[1], 2);
  39
  40                 execvp(argv_[0], argv_);
  41                 ::exit(1);
  42         }
  43         else if(pid==-1)
  44                 cerr<<"Failed to execute "<<argv.front()<<'\n';
  45         else
  46         {
  47                 close(pfd[1]);
  48                 while(1)
  49                 {
  50                         char buf[1024];
  51                         int len=read(pfd[0], buf, sizeof(buf));
  52                         if(len<=0)
  53                         {
  54                                 if(waitpid(pid, 0, WNOHANG))
  55                                         break;
  56                         }
  57                         else
  58                                 result.append(buf, len);
  59                 }
  60         }
  61
  62         return result;
  63 }
  64
  65