There is a common mechanism for all descriptors, to check whether a descriptor is ready for reading/writing, please check out IO::Select.
The main point is to call can_read or can_write before you really go reading/writing. This way, you even don't need to bother blocking/non-blocking mode. More important, you gain a better control.
On the other hand, I attached a simple sample to show pipe:
parn.pl:
use strict;
use warnings;
$| ++;
print "Entering parn.pl...\n";
my $chld;
open($chld, "perl -w chld.pl|") || die "failed to open child process\n
+";
my @ready;
while (1) {
my $from_chld = <$chld>;
print $from_chld * 2, "\n";
}
chld.pl:
use strict;
use warnings;
$| ++;
while (<>) {
if ($_ < 100) {
print "$_";
}
}
Update: for getc, although it returns one char a time, but unfortunately, this only happens after return is hit. An alternative way is presented in perlfunc under getc.
-
Are you posting in the right place? Check out Where do I post X? to know for sure.
-
Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
<code> <a> <b> <big>
<blockquote> <br /> <dd>
<dl> <dt> <em> <font>
<h1> <h2> <h3> <h4>
<h5> <h6> <hr /> <i>
<li> <nbsp> <ol> <p>
<small> <strike> <strong>
<sub> <sup> <table>
<td> <th> <tr> <tt>
<u> <ul>
-
Snippets of code should be wrapped in
<code> tags not
<pre> tags. In fact, <pre>
tags should generally be avoided. If they must
be used, extreme care should be
taken to ensure that their contents do not
have long lines (<70 chars), in order to prevent
horizontal scrolling (and possible janitor
intervention).
-
Want more info? How to link
or How to display code and escape characters
are good places to start.
|