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