in reply to searching the strings

Let's see if I understood everything:

foreach (@w) {
  print "working with $_... ";
  /^>>/                and do { print "error message\n"; next };
  /^\s*([<>])\s*(\S+)/ and do { print "separated '$1' from '$2'\n"; ne
+xt };
  /^\s*\|/             and do { print "pipefront\n"; next };
  /\|\s*$/             and do { print "pipeend\n"; next };
  print "\n";
}
__END__
working with >test.txt... separated '>' from 'test.txt'
working with <test.txt... separated '<' from 'test.txt'
working with >>test.txt... error message
working with  | test... pipefront
working with test |... pipeend

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This probably needs more refinement but I think I'll leave that to you ;).

Update: Code beautification.

--
David Serrano

Replies are listed 'Best First'.
Re^2: searching the strings
by blazar (Canon) on May 10, 2006 at 13:21 UTC 
    /^>>/ and do { print "error message\n"; next };

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    I like to use short-circuiting logical operators for flow control, and to omit unnecessary parentheses, but I'd avoid using do like that, if possible. How 'bout the following instead?

    print("error message\n"), next if /^>>/;
# or
(print "error message\n"), next if /^>>/;

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      I've seen it in the Camel ("2.6. Statements and declarations", "Bare blocks and case structures"), so I thought it would be ok. Indeed I think it's ok since it is listed only as one of several alternatives (another one of which is the one you posted).

      --
      David Serrano

[reply]
[d/l]

        The alternative the grandparent suggested
        print("error message\n"), next if /^>>/;
        could easily be confused for
        print("error message\n"); next if /^>>/;
        I don't think it's a very good idea.

        At least what you used is well established. It is quite ugly, though. I usually fall back to if/elsif. if/elsif even produces shorter lines: 

        foreach (@w) {
  print "working with $_... ";
  if    (/^>>/               ) { print "error message\n"            }
  elsif (/^\s*([<>])\s*(\S+)/) { print "separated '$1' from '$2'\n" }
  elsif (/^\s*\|/            ) { print "pipefront\n"                }
  elsif (/\|\s*$/            ) { print "pipeend\n"                  }
  else                         { print "\n"                         }
}

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