On Tue, Sep 24, 2002 at 12:15:08PM -0400, Erik Price wrote:
>
> PS: I'm trying to think of an elegant and simple way to read <STDIN> if
> there is any standard input and read <DATA> if not. Yes, I could just
> test for <STDIN> != "" or something and use "if" statements, but that
> would basically mean repeating the same chunk of code with a different
> file handle inside the <>. Any good ideas that let me just use the
> same block in either case?
You haven't said much about your problem, but you can use a simple
variable in <> such as:
$fh = is_there_any_standard_input() ? \*STDIN : \*DATA;
while (<$fh>) {
...
}
Or in one step (fails on old Perls):
while (readline(is_there_any_standard_input() ? \*STDIN : \*DATA)) {
...
}
You can't use angle brackets for expressions like this, because Perl
regards them as the glob() operator. readline($fh) is the same as
<$fh>.
How you detect whether "there is any standard input" (or what you mean
by that) is another interesting question. Here is one answer.
sub is_there_any_standard_input {
return (-f(STDIN) || -p(STDIN)); # true if STDIN is a file or pipe
}
Hope this helps.
--
John Tobey <[EMAIL PROTECTED]>
\____^-^
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