What BrowserUk says - use INIT, not BEGIN, since BEGIN blocks are executed in the compile phase of the perl script.

I want to write something of a generic tracer for any perl script.

Why? GNU/Linux has tools for that ready - strace(1), ltrace(1). I suspect an XY problem here. What are you trying to to with that which you are ostensibly trying to do?

Then, perl is linked against many libraries, and it can well be that most of those syscalls happen inside calls to functions in these libraries. To verify that, you can use ltrace(1), which displays library calls, together with the -S switch to display system calls as well.

In reply to Re^3: tracing system calls a perl script is making by shmem
in thread tracing system calls a perl script is making by gideondsouza

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.