There's a potential subtle problem with using env, which is that you typically can't pass arguments to the perl binary this way, like for example 

#!/usr/bin/env perl -w

[download]

On my Debian Linux this produces 

$ ./666330.pl
/usr/bin/env: perl -w: No such file or directory

[download]

This is not a problem with env (running /usr/bin/env perl -w 666330.pl from the command line would work fine...), but rather with many Unix kernels, which treat everything after the interpreter specified on the shebang line (here /usr/bin/env) as a single argument, i.e. it would pass "perl -w" to /usr/bin/env as the program name to execute... which of course doesn't exist. This can easily be seen with strace: 

$ strace -e trace=execve ./666330.pl
execve("./666330.pl", ["./666330.pl"], [/* 24 vars */]) = 0
execve("/home/almut/bin/perl -w", ["perl -w", "./666330.pl"], [/* 24 v
+ars */]) = -1 ENOENT (No such file or directory)
execve("/usr/local/bin/perl -w", ["perl -w", "./666330.pl"], [/* 24 va
+rs */]) = -1 ENOENT (No such file or directory)
execve("/usr/bin/perl -w", ["perl -w", "./666330.pl"], [/* 24 vars */]
+) = -1 ENOENT (No such file or directory)
execve("/bin/perl -w", ["perl -w", "./666330.pl"], [/* 24 vars */]) = 
+-1 ENOENT (No such file or directory)
execve("/usr/bin/X11/perl -w", ["perl -w", "./666330.pl"], [/* 24 vars
+ */]) = -1 ENOENT (No such file or directory)
/usr/bin/env: perl -w: No such file or directory

[download]

In reply to Re^2: Can I write a transparent shell wrapper to start the correct build of Perl? by almut
in thread Can I write a transparent shell wrapper to start the correct build of Perl? by thparkth

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.