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 <fcntl.h>
  11 #include <cstdlib>
  12 #include <cstring>
  13 #include "misc.h"
  14
  15 using namespace std;
  16 using namespace Msp;
  17
  18 /**
  19 Runs a command and returns its output as a string.  The exit status of the
  20 command is lost.
  21 */
  22 string run_command(const StringList &argv)
  23 {
  24         int pfd[2];
  25         pipe(pfd);
  26
  27         string result;
  28
  29         pid_t pid=fork();
  30         if(pid==0)
  31         {
  32                 char *argv_[argv.size()+1];
  33
  34                 unsigned j=0;
  35                 for(StringList::const_iterator i=argv.begin(); i!=argv.end(); ++i)
  36                         argv_[j++]=strdup(i->c_str());
  37                 argv_[j]=0;
  38
  39                 close(pfd[0]);
  40                 dup2(pfd[1], 1);
  41                 close(pfd[1]);
  42                 int devnull=open("/dev/null", O_WRONLY);
  43                 dup2(devnull, 2);
  44                 close(devnull);
  45
  46                 execvp(argv_[0], argv_);
  47                 ::exit(1);
  48         }
  49         else if(pid==-1)
  50                 cerr<<"Failed to execute "<<argv.front()<<'\n';
  51         else
  52         {
  53                 close(pfd[1]);
  54                 while(1)
  55                 {
  56                         char buf[1024];
  57                         int len=read(pfd[0], buf, sizeof(buf));
  58                         if(len<=0)
  59                         {
  60                                 if(waitpid(pid, 0, WNOHANG))
  61                                         break;
  62                         }
  63                         else
  64                                 result.append(buf, len);
  65                 }
  66         }
  67
  68         return result;
  69 }
  70
  71