What difference should putting the "print $_;" statement after the next statement make?

1st version

while (<$client_sock>) {
print $_;
next if (/Proxy-Connection:/);
print $server_sock $_;
last if ($_ =~ /^[\s\x00]*$/);
}

2nd version

while (<$client_sock>) {
next if (/Proxy-Connection:/);
print $_;
print $server_sock $_;
last if ($_ =~ /^[\s\x00]*$/);
}

The 1st version works for me, the 2nd doesn't. To me, they both do the same thing. Can someone explain to me the difference? My confusion is probably due to a misunderstanding of how $_ works.

Thanks
Greg

: What difference should putting the "print $_;" statement after the
: next statement make?
The order in which they are executed. If you're writing print $_; then you're not really taking advantage of $_. You could just put print; - $_ is the "default variable" for many operations. Having said that, the print $server_sock $_ line is a place you want to be explicit about it.

: 1st version
:
: while (<$client_sock>) {
: print $_;
: next if (/Proxy-Connection:/);
: print $server_sock $_;
: last if ($_ =~ /^[\s\x00]*$/);
: }
Will print the contents of $_ out, then test if it contains Proxy-Connection: and skip the rest of the loop if it does, going to the next line of input that can be read from $client_sock.

: 2nd version
:
: while (<$client_sock>) {
: next if (/Proxy-Connection:/);
: print $_;
: print $server_sock $_;
: last if ($_ =~ /^[\s\x00]*$/);
: }
This will check if $_ contains Proxy-Connection: and if it does jump over the statements in the while loop and try to fetch the next line.

: The 1st version works for me, the 2nd doesn't. To me, they both do
: the same thing.
It's like asking whether:-
print "hello!";
die;
And:-
die;
print "hello!";
Do the same thing really. Statements are executed in the order you write them.

: Can someone explain to me the difference? My confusion is probably
: due to a misunderstanding of how $_ works.
$_ is the default variable. Examples:-

while (<$some_handle>) {
    # $_ will contain each line we read from $some_handle
    s/foo/bar/; # Replace all instances of foo with bar in $_
    print; # Print the contents of $_ (with foos and bars).
}

# Also good in for loops.  This prints all elements in an
# array (bit of a waste...).
for (@array) {
    print;
}

# Or is you're lazy like me:-
print for (@array);

Hope this helps,

Jonathan

###
for(74,117,115,116){$::a.=chr};(($_.='qwertyui')&&
(tr/yuiqwert/her anot/))for($::b);for($::c){$_.=$^X;
/(p.{2}l)/;$_=$1}$::b=~/(..)$/;print("$::a$::b $::c hack$1.");