Re^3: Unix rename behaviour

Well, he meant "rename" when he said "rename"?! (it's linked to perl rename)

-> Code should look like this

$ cat foo.pl 
#!/usr/bin/perl -w
##################
open(OUT,">testfileA");
print OUT "This is testfileA\n";
close(OUT);

open(OUT,">testfileB");
print OUT "This is testfileB\n";
close(OUT);

open(IN,"/tmp/testfileA");

rename ("testfileB", "testfileA");

print <IN>;
close IN;
[download]

Yields:

$ ./foo.pl 
readline() on closed filehandle IN at ./foo.pl line 15.
[download]

So the answer is "neither - rename closes the filehandle". I.

Comment on Re^3: Unix rename behaviour Select or Download Code

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Re^4: Unix rename behaviour by BrowserUk (Patriarch) on May 03, 2006 at 10:04 UTC
So the answer is "neither - rename closes the filehandle". I think you missed the bit about "... two concurrent (Perl) processes ..." and "... when the second process next reads via it's open handle ..." A better test would be `#!/usr/bin/perl use strict; use warnings; open OUT, '>', 'junk.1' or die $!; print OUT 'X'x 20 . "$_\n" for 1 .. 20; close OUT; open OUT, '>', 'junk.2' or die $!; print OUT 'Y'x 20 . "$_\n" for 1 .. 20; close OUT; open IO, '+<', 'junk.1' or die $!; seek IO, 0, 0; print scalar <IO>; system $^X, '-le', q[ print rename( 'junk.2', 'junk.1' ) ? 'worked' : +'failed']; print scalar <IO>; seek IO, 0, 0; print scalar <IO>; close IO; unlink 'junk.1';` [download] Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error. Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal? "Science is about questioning the status quo. Questioning authority". In the absence of evidence, opinion is indistinguishable from prejudice.	[reply] [d/l]

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Re^4: Unix rename behaviour
by BrowserUk (Patriarch) on May 03, 2006 at 10:04 UTC

So the answer is "neither - rename closes the filehandle".

I think you missed the bit about "... two concurrent (Perl) processes ..." and "... when the second process next reads via it's open handle ..."

A better test would be

#!/usr/bin/perl
use strict;
use warnings;

open OUT, '>', 'junk.1' or die $!;
print OUT 'X'x 20 . "$_\n" for 1 .. 20;
close OUT;

open OUT, '>', 'junk.2' or die $!;
print OUT 'Y'x 20 . "$_\n" for 1 .. 20;
close OUT;

open IO, '+<', 'junk.1' or die $!;
seek IO, 0, 0;
print scalar <IO>;

system $^X, '-le', q[ print rename( 'junk.2', 'junk.1' ) ? 'worked' : 
+'failed'];

print scalar <IO>;

seek IO, 0, 0;

print scalar <IO>;

close IO;

unlink 'junk.1';
[download]

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

Lingua non convalesco, consenesco et abolesco. -- Rule 1 has a caveat! -- Who broke the cabal?

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

[reply]
[d/l]