Re^2: Unix rename behaviour

[ioannis]

True, but I think the OP meant "cp" and not "mv" when refering to the rename(?) command. Although the cp(1) command will create a new inode, the already opened filehandles are pointing to older inodes.

[Anonymous Monk]

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;


Yields:

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

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

[BrowserUk]

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';