[EMAIL PROTECTED] wrote:
>
> Case 3. (this is the difficult case for me) the script is invoked
> with no file and no pipe to it. I would like the script to
> end quietly, such as
>>test.input.source
>>
>
> Instead, it waits for input.
>
>> test.input.source
> no command line args - switching to STDIN
>
>
> and now it waits forever.
select / IO::Select is what you are looking for. i suggested the following
to someone who asked exactly the same question a while back. if you have
searched this group hard enough, you would have found the solution:
#!/usr/bin/perl -w
use strict;
#--
#-- script.pl
#--
use IO::Select;
if(@ARGV){
print join("\n", "get file: ",@ARGV) . "\n";
}else{
my $buf;
my $line;
my $io = IO::Select->new(\*STDIN);
while($io->can_read(0)){
last unless(sysread(STDIN,$buf,1024));
$line .= $buf;
}
if(defined $line){
print "get line $line";
}else{
print STDERR "no input\n";
}
}
__END__
[panda]$ script.pl
no input
[panda]$ script.pl file.html
get file:
file.html
[panda]$ echo "hi" | script.pl
get line hi
[panda]$
perldoc -f select
perldoc IO::Select
david
--
sub'_{print"@_ ";* \ = * __ ,\ & \}
sub'__{print"@_ ";* \ = * ___ ,\ & \}
sub'___{print"@_ ";* \ = * ____ ,\ & \}
sub'____{print"@_,\n"}&{_+Just}(another)->(Perl)->(Hacker)
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