Re^2: if -s clause on a FILEHANDLE

what exactly is


select( (select(OUT),$|=1)[0] )
[download]

saying? I still want to state

if ( -s "@ftapes" ) {

    .....
}
[download]

right? not just if ( "@ftapes" )

Comment on Re^2: if -s clause on a FILEHANDLE Select or Download Code

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Re^3: if -s clause on a FILEHANDLE by Fletch (Bishop) on Jun 08, 2004 at 14:42 UTC
The select stuff is a hackish shortcut from the dawn of time (or at lest the perl4 days) to set autoflush on a handle without changing the current default output handle afterwards. The chunk inside the inner parens is a list consisting of the previous default output handle (what you were getting with `my $svsel = select OUT;`) and then setting `$\|` on the default output handle (which is then `OUT` since the `select` executes first). The list value is subscripted to get just the first element (the old saved handle) and that's passed to `select` to reset the default output handle. And no, you don't want `-s "@ftapes"`. `-s` gets the size of a file (either by name or for an already opened filehandle). Yours would attempt to find the size of a file named after the contents of `@ftapes` joined by `$,`. Using an array in a scalar context evaluates to the number of items in the array; if you found any items then `@ftapes` will have a non-zero number of elements and evaluate to a true boolean value.	[reply] [d/l] [select]
Re^4: if -s clause on a FILEHANDLE by drock (Beadle) on Jun 08, 2004 at 21:43 UTC
Is there a ideal way to "touch" a file instead of opening a file then >$foo it? for example, `my $foo="/tmp/ftapes_runfile"; open (RUNFILE, ">$foo") \|\| die "could not open runfile: $!;" close (RUNFILE);` [download] thanks!	[reply] [d/l]