First try wrapping your sample code in code tags to make it readable, so it looks like this: 
foreach $x (@x) {  
   open ($x, ">>$log") or die;  
   print while (<$x>);  
   printf "%7d",$x; 
}  

close ($x);

[download]
A more common idiom for printing to a file would be this: 

open (OUTPUT, ">>$log") or die "Error opening file $log ($!)\n";
my $line = join ' ', @x;
print OUTPUT $line, "\n";
close (OUTPUT) or die "Error closing file $log ($!)\n";

[download]
Catching possible errors from your system IO operations in $! is generally a good practice. Also, the version I showed doesn't reopen the filehandle every time you want to print a array element to the file. The join operator is very useful, do a perldoc -f join if you've never seen it before. A perldoc -f open would probably be helpful to you as well.

Hope that this helps. :)

In reply to Re: efficient Array printing to a file by biosysadmin
in thread efficient Array printing to a file by Anonymous Monk

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post, it's "PerlMonks-approved HTML":


  • Posts are HTML formatted. Put <p> </p> tags around your paragraphs. Put <code> </code> tags around your code and data!
  • Titles consisting of a single word are discouraged, and in most cases are disallowed outright.
  • Read Where should I post X? if you're not absolutely sure you're posting in the right place.
  • Please read these before you post! —
  • Posts may use any of the Perl Monks Approved HTML tags:
    a, abbr, b, big, blockquote, br, caption, center, col, colgroup, dd, del, details, div, dl, dt, em, font, h1, h2, h3, h4, h5, h6, hr, i, ins, li, ol, p, pre, readmore, small, span, spoiler, strike, strong, sub, summary, sup, table, tbody, td, tfoot, th, thead, tr, tt, u, ul, wbr
  • You may need to use entities for some characters, as follows. (Exception: Within code tags, you can put the characters literally.)
            For:     Use:
    & &amp;
    < &lt;
    > &gt;
    [ &#91;
    ] &#93;
  • Link using PerlMonks shortcuts! What shortcuts can I use for linking?
  • See Writeup Formatting Tips and other pages linked from there for more info.