如何指定Perl系统调用的超时限制?

见 alarm 功能。pod示例:

eval {
    local $SIG{ALRM} = sub { die "alarm\n" }; # NB: \n required
    alarm $timeout;
    $nread = sysread SOCKET, $buffer, $size;
    alarm 0;
};
if ($@) {
    die unless $@ eq "alarm\n";   # propagate unexpected errors
    # timed out
}
else {
    # didn't
}

在CPAN上有一些模块可以更好地包装这些内容,例如: Time::Out

use Time::Out qw(timeout) ;

timeout $nb_secs => sub {
  # your code goes were and will be interrupted if it runs
  # for more than $nb_secs seconds.
};

if ($@){
  # operation timed-out
}

IPC::Run 的运行方法,而不是系统。并设置超时。

怎么样 System::Timeout ?

此模块扩展 system

timeout("3", "sleep 9"); # timeout exit after 3 seconds

我刚刚用了 timeout 命令在Perl+Linux之前,您可以这样测试:

for(0..4){
  my $command="sleep $_";  #your command
  print "$command, ";
  system("timeout 1.1s $command");  # kill after 1.1 seconds
  if   ($? == -1  ){ printf "failed to execute: $!" }
  elsif($?&127    ){ printf "died, signal %d, %scoredump", $?&127, $?&128?'':'no '}
  elsif($?>>8==124){ printf "timed out" }
  else             { printf "child finished, exit value %d", $? >> 8 }
  print "\n";
}

4.317秒后输出:

sleep 0, child finished, exit value 0
sleep 1, child finished, exit value 0
sleep 2, timed out
sleep 3, timed out
sleep 4, timed out

这个 超时