how to continue in the loop after traping signal in perl

tprayush · 05-02-2010, 05:10 PM

hi all....

plz tel me how can i solve this....here's the situation (this is just a sample!!)..

Code:

$ cat sigtrap
#!/usr/bin/perl
$SIG{'INT'} = 'ABORT';
    sub ABORT {
    print "\nStop the loop?? (y/n) : ";
        chop($ch=<STDIN>);
       
 if ($ch =~ /[yY]/)
    {     
    
         
    exit(1);

     }
  else
   {
     redo;
   }
    }
$no=0;
while (1)
 {
   print "$no\n";
   sleep 2;
   $no++
 }

Code:

$ ./sigtrap
0
1
2
3
^C
Stop the loop?? (y/n) : n
Can't "redo" outside a loop block at ./sigtrap line 16, <STDIN> line 1.

by using 'trap' in bash...we can continue in loop....if we write 'trap' in the loop...

but how can i solve this in perl!! plz help!!

thanx.

Sergei Steshenko · 05-02-2010, 05:22 PM

Quote:

Originally Posted by tprayush

hi all....

plz tel me how can i solve this....here's the situation (this is just a sample!!)..

Code:

$ cat sigtrap
#!/usr/bin/perl
$SIG{'INT'} = 'ABORT';
    sub ABORT {
    print "\nStop the loop?? (y/n) : ";
        chop($ch=<STDIN>);
       
 if ($ch =~ /[yY]/)
    {     
    
         
    exit(1);

     }
  else
   {
     redo;
   }
    }
$no=0;
while (1)
 {
   print "$no\n";
   sleep 2;
   $no++
 }

Code:

$ ./sigtrap
0
1
2
3
^C
Stop the loop?? (y/n) : n
Can't "redo" outside a loop block at ./sigtrap line 16, <STDIN> line 1.

by using 'trap' in bash...we can continue in loop....if we write 'trap' in the loop...

but how can i solve this in perl!! plz help!!

thanx.

You could use better indentation - the code looks disorderly.

Reading from STDIN in signal handler is a very bad idea - the handler should be as quick as possible.

Use signal handler to set a flag and analyze the flag value inside your loop. Depending on the flag value do or do not read from STDIN and continue or not depending on the value read from STDIN.