MPI Module

rachanaj has asked for the wisdom of the Perl Monks concerning the following question:

Hi,
I am trying to use the MPI module for the first time. I use the following command:

$>mpirun -np 1 mpitest.pl

and get the following error:

: bad interpreter: No such file or directorypitest.pl: /usr/local/bin/perl

The code is attached below:

#!/usr/bin/perl

use Parallel::MPI qw(:all);

# Start up MPI
MPI_Init();

# Find out process rank
$my_rank = MPI_Comm_rank(MPI_COMM_WORLD);

# Find out number of processes
$num_procs = MPI_Comm_size(MPI_COMM_WORLD);

$infilename = "sequences.txt";

open(INFILE, $infilename);
@sequences = <INFILE>;
close(INFILE);

$num_seq = $#sequences + 1;

$seq_per_file = int $num_seq / $num_procs;

$start_seq = $my_rank * $seq_per_file;

if ($my_rank < $num_procs)
{
    $end_seq = ($my_rank + 1) * $seq_per_file - 1;
}
else #deal with last processor separately
{
    $end_seq = $num_seq;
}

foreach ($start_seq..$end_seq)
{
    ; #Stuff to do with sequences
    
}

MPI_Finalize();
[download]

Any ideas about the problem are welcome.
Thanks
-Rachana

Comment on MPI Module Download Code

Replies are listed 'Best First'.
Re: MPI Module by muntfish (Chaplain) on Nov 26, 2004 at 10:28 UTC
As BUU already suggested, this is probably because `/usr/local/bin/perl` does not exist. What is curious though, is that your code says `#!/usr/bin/perl` not `#!/usr/local/bin/perl` ...? Maybe that was just a typo/cut'n'paste error on your part. If not then I'm not sure what's going on. One other thing that could cause this error is some spurious CR/LF characters on the end of the `#!` line. For example if you developed the Perl script on a Windows machine then FTPed it to your Unix box, but forgot to transfer it in ASCII mode, then the `#!` line will have an ASCII-13 at the end which confuses most Unix shells. Some Unix editors (I think EMACS does this) will show this up as: `#!/usr/bin/perl^M` . Not sure if that's the problem in this case but it's something to look out for. s^^unp(;75N=&9I<V@`ack(u,^;s\|$.+\`\|"$`$'\"$&\"$"\|ee;/m.+h/&&print$&	[reply] [d/l] [select]
Re: MPI Module by BUU (Prior) on Nov 26, 2004 at 10:16 UTC
The error you quote: `bad interpreter: No such file or directorypitest.pl: /usr/local/bin/perl` is not a perl error, it is a bash (or possibly some other shell) that is attempting to run the interpreter specified on the shebang line of the file. The specified interpreter doesn't exist, so it errors.	[reply] [d/l]