I am puzzled as to how to test for a read() failure across two platform we deploy to here.

Background:
I am writing coverage tests, using Devel::Cover. The coverage tests are for a module that reads encoded files and turns their contents into an object representation.

Problem:
I have tests that check the modules behaviour when there are various problems with the file e.g. file doesn't exist, is zero length, is actually a directory, we dont have adequate permissions etc.

But the problem I am having is testing read failures on a file I have successfully opened. And to have those tests work on both Linux and Solaris (others would be nice - but those at a minimum).

Partial Solution:
I have tests that work correctly (that is, cause a read() to fail on a successfully opened file) on Linux, but they dont work on Solaris.

To get the Linux test working, I did this

<File.t>
...
my $obj = Widget::File->new(filename   => $testfile, # a real file
                            otherstuff => ...);
my $dirh = IO::File->new('/', O_RDONLY); # reading a dirhandle forces 
+a read() failure on Linux
$obj->{fh} = $dirh;

# invoke a method that calls read() internally
eval {
    $obj->header(); # read()ing from a dirhandle forces an EISDIR erro
+r
};

like($@, qr(Error in reading file header - Is a directory at ));
</File.t>

[download]

But this doesn't work on Solaris - instead I get this 

./t/File..........NOK 71#     Failed test (./t/File.t at line 191)
#                   ''
#     doesn't match '(?-xism:Error in reading file header - Is a direc
+tory at )'
./t/File..........ok 73/0# Looks like you failed 1 tests of 73.

[download]

Now I expect that Solaris is actually returning EISDIR in errno at the C library level, but this isn't propagating up to Perl in Solaris the same way it does in Linux - and hence the regex error.

BTW
Solaris perl == 5.8.1
Linux perl == 5.8.3

So, please, can anyone advise me on a better way for testing cross platform read failures?

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

In reply to Testing for read() failures on different platforms by leriksen

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