source/externaltask.cpp

   1 #include <cstdlib>
   2 #include <unistd.h>
   3 #include <sys/wait.h>
   4 #include <msp/fs/dir.h>
   5 #include <msp/io/console.h>
   6 #include <msp/io/file.h>
   7 #include <msp/io/print.h>
   8 #include <msp/time/units.h>
   9 #include "externaltask.h"
  10
  11 using namespace std;
  12 using namespace Msp;
  13
  14 ExternalTask::ExternalTask(const Arguments &a, const FS::Path &wd):
  15         argv(a),
  16         work_dir(wd),
  17         process(0),
  18         exit_code(-1),
  19         stdout_dest(PASSTHROUGH),
  20         stderr_dest(PASSTHROUGH),
  21         capture_pipe(0)
  22 {
  23         if(argv.empty())
  24                 throw invalid_argument("ExternalTask::ExternalTask");
  25 }
  26
  27 ExternalTask::~ExternalTask()
  28 {
  29         delete capture_pipe;
  30 }
  31
  32 string ExternalTask::get_command() const
  33 {
  34         string cmd;
  35         for(vector<string>::const_iterator i=argv.begin(); i!=argv.end(); ++i)
  36         {
  37                 if(i!=argv.begin())
  38                         cmd += ' ';
  39
  40                 for(string::const_iterator j=i->begin(); j!=i->end(); ++j)
  41                 {
  42                         if(*j=='"' || *j=='\'' || *j==' ' || *j=='\\' || *j=='&')
  43                                 cmd += '\\';
  44                         cmd += *j;
  45                 }
  46         }
  47
  48         return cmd;
  49 }
  50
  51 void ExternalTask::start()
  52 {
  53         IO::File *devnull = 0;
  54
  55         prepare();
  56
  57         process = new Process;
  58
  59         if(stdout_dest==IGNORE || stderr_dest==IGNORE)
  60         {
  61                 devnull = new IO::File("/dev/null", IO::M_WRITE);
  62                 if(stdout_dest==IGNORE)
  63                         process->redirect_cout(*devnull);
  64                 if(stderr_dest==IGNORE)
  65                         process->redirect_cerr(*devnull);
  66         }
  67
  68         if(stdout_dest==CAPTURE || stderr_dest==CAPTURE)
  69         {
  70                 capture_pipe = new IO::Pipe;
  71                 if(stdout_dest==CAPTURE)
  72                         process->redirect_cout(*capture_pipe);
  73                 if(stderr_dest==CAPTURE)
  74                         process->redirect_cerr(*capture_pipe);
  75         }
  76
  77         if(!work_dir.empty())
  78                 process->set_working_directory(work_dir);
  79
  80         Process::Arguments args(argv.begin()+1, argv.end());
  81         process->execute(argv.front(), args);
  82         if(capture_pipe)
  83                 capture_pipe->set_mode(IO::M_READ);
  84
  85         delete devnull;
  86 }
  87
  88 Task::Status ExternalTask::check()
  89 {
  90         return do_wait(false);
  91 }
  92
  93 Task::Status ExternalTask::wait()
  94 {
  95         return do_wait(true);
  96 }
  97
  98 Task::Status ExternalTask::do_wait(bool block)
  99 {
 100         if(process)
 101         {
 102                 if(process->wait(block))
 103                 {
 104                         exit_code = process->get_exit_code();
 105                         delete process;
 106                         process = 0;
 107                 }
 108
 109                 // Do this after waiting to avoid a race condition
 110                 while(capture_pipe && IO::poll(*capture_pipe, IO::P_INPUT, Time::zero))
 111                 {
 112                         char buf[1024];
 113                         unsigned len = capture_pipe->read(buf, sizeof(buf));
 114                         if(len)
 115                                 output.append(buf, len);
 116                         else
 117                                 break;
 118                 }
 119
 120                 if(process)
 121                         return RUNNING;
 122                 else
 123                         signal_finished.emit(!exit_code);
 124         }
 125
 126         return exit_code ? ERROR : SUCCESS;
 127 }
 128
 129 void ExternalTask::set_stdout(Destination d)
 130 {
 131         stdout_dest = d;
 132 }
 133
 134 void ExternalTask::set_stderr(Destination d)
 135 {
 136         stderr_dest = d;
 137 }
 138
 139 string ExternalTask::run_and_capture_output(const Arguments &argv, const FS::Path &wd)
 140 {
 141         ExternalTask task(argv, wd);
 142         task.set_stdout(CAPTURE);
 143         task.set_stderr(IGNORE);
 144         task.start();
 145         if(task.wait()!=SUCCESS)
 146                 throw runtime_error(format("%s failed", argv.front()));
 147         return task.get_output();
 148 }