perl6 – 在Perl 6中捕获shell命令的异常

$cat prog.sh 
echo "error" >&2
exit 1

put "start";
  try {
    sHell "./prog.sh";
  }
put "end";

start
error
The spawned command './prog.sh' exited unsuccessfully (exit code: 1)
  in block <unit> at b.P6 line 2

put "start";
  try {
    sHell "./prog.sh";
    CATCH { default {} }
  }
put "end";

start
error
end

sHell在 sink之前不会抛出异常. @H_675_5@只有sHell的try块完全执行而没有抛出异常,返回块中的最后一个值,然后在try的上下文之外沉没,然后抛出异常.

@H_675_5@你可以看到这个：

put "start";
  try {
    sHell "./prog.sh";
    'something';
  }
put "end";

@H_675_5@现在sHell陷入了try,它被try的隐式CATCH捕获. try块返回块中的最后一个值’something’,然后安全地在try之外沉没.

@H_675_5@您还可以强制接收器在try中发生：

put "start";
try {
   sink sHell "./prog.sh"
}
put "end";

@H_675_5@您添加的CATCH块只是阻止try块从sHell返回返回值.

@H_675_5@你可以重新安排它们,看看它仍然会爆炸：

put "start";
try {
    CATCH { default {} }
    sHell "./prog.sh";
}
put "end";

@H_675_5@处理这个恕我直言的最好,最清晰的方法是自己检查sHell的返回,而不是让它下沉并抛出异常：

put "start";
if sHell "./prog.sh" {
    say 'ok'
}
else {
    say 'failed'
}
put "end";