Beefy Boxes and Bandwidth Generously Provided by pair Networks
more useful options
 
PerlMonks  

comment on

( #3333=superdoc: print w/replies, xml ) Need Help??
Dear Wise Monks, One of my programs has a simple counter that counts the number of times the program has run. Below is the relevent portion that handles this task. My problem is that sometimes the counter mysteriously loses count and starts from the beginning again, as if the contents were erased somehow. This happens during times when traffic is high and people are accessing the script at the same time on the internet. Can you shed light on why the file contents "disappear"? Thanks in advance.
$completeadd = "mycounter"; $semaphore_file = "mycounterlock"; open(SEM, ">$semaphore_file") || die "Cannot create semaphore $semapho +re_file: $!"; flock(SEM, LOCK_EX) || die "Lock failed: $!"; open(MFILE, ">>$completeadd") || die "file open1 failed: $!\n"; close(MFILE); open(MFILE, "$completeadd") || die "file open2 failed: $!\n"; @filedata1=<MFILE>; chomp @filedata1; close(MFILE); $hitcount=$filedata1[0]; if ($hitcount) { $hitcount=$hitcount + 1; } else { $hitcount = 1; } $filedata1[0]=$hitcount; writedata(@filedata1); release_lock();

In reply to Mysterious Disapperance of file contents by Gorby

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, 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, 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.
  • Log In?
    Username:
    Password:

    What's my password?
    Create A New User
    Chatterbox?
    and the web crawler heard nothing...

    How do I use this? | Other CB clients
    Other Users?
    Others examining the Monastery: (5)
    As of 2020-06-06 20:24 GMT
    Sections?
    Information?
    Find Nodes?
    Leftovers?
      Voting Booth?
      Do you really want to know if there is extraterrestrial life?



      Results (41 votes). Check out past polls.

      Notices?