Re: Permission denied when opening files in Windows

I'd recommend adding an 'or die' statement to your open statement like:

open(my $fh2, ">", $output) or die "Unable to open file '$output':  $!
+\n";
[download]

Your code has a check on closing the file, but not on opening the file. Modifying your open statement to something like what I listed above will show you when the code encounters an issue with opening a file. I personally like to use the die message listed above because it will show me both the file name/path that was provided to open as well as the reason for failing to open the file.

Comment on Re: Permission denied when opening files in Windows Download Code

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Re^2: Permission denied when opening files in Windows by Laurent_R (Canon) on Mar 27, 2015 at 19:00 UTC
I agree with you, but would suggest it is better not to have `"\n"` at the end of the `die` message. You get more information from ~~`$!`~~ `die` without it. Update: Thanks tye: more information from `die`, not from `$!` as originally written. Je suis Charlie.	[reply] [d/l] [select]
Re^3: Permission denied when opening files in Windows ($! $^E) by tye (Sage) on Mar 28, 2015 at 04:44 UTC
it is better not to have "\n" at the end of the die message. You get more information from $! without it. The extra information has nothing to do with `$!` (see die for details). BTW, since you (the OP) are using Windows, you may want to include $^E in addition to $! as $^E will sometimes have a more to-the-point explanation, especially in "permission denied" scenarios. - tye	[reply] [d/l]
Re^3: Permission denied when opening files in Windows by dasgar (Priest) on Mar 29, 2015 at 17:13 UTC
I'm not saying that you're wrong about that, but can you point me to where this behavior change of $! is documented? I have never tried testing to see if `die "$!"` provides more information than `die "$!\n"`. The reason that I have been including "\n" is that I'm primarily working on Windows and I have seen instances where not using "\n", the next command prompt is being displayed on the last output line of the die statement. That's not necessarily a major issue, but I do find that to be a bit annoying. By adding "\n", this puts the next command prompt on a new line. After seeing your post, I've looked at the perldocs for open, perliol, perlopentut, and perlvar and I was not able to find anything that indicated that "\n" would affect the contents of $!. If what you are saying is true, then it might a good idea if the perldoc for open could be updated since there are a few examples of open or die structure that has "$!\n" in the input to the die statement. On the other hand, I did find information in perlvar that corroborates what tye said about $^E potentially providing more detailed information on some operating systems (including Windows).	[reply] [d/l] [select]
Re^4: Permission denied when opening files in Windows by Anonymous Monk on Mar 29, 2015 at 18:56 UTC
I have never tried testing to see if `die "$!"` provides more information than `die "$!\n"`. It does: `$ perl -e 'open FOO, "<", "dontexist" or die "$!\n"' No such file or directory $ perl -e 'open FOO, "<", "dontexist" or die "$!"' No such file or directory at -e line 1.` [download] It can also provide information on the currently open file, see e.g. second example here. I was not able to find anything that indicated that "\n" would affect the contents of $!. AFAIK it doesn't. Perhaps Laurent_R meant to say "You get more information from `die` without it."	[reply] [d/l] [select]
Re^4: Permission denied when opening files in Windows by Laurent_R (Canon) on Mar 30, 2015 at 05:41 UTC
Sorry, I typed this a bit too fast. As pointed out by tye and anonymous monk, the difference is associated with `die` rather that with `$!` Je suis Charlie.	[reply] [d/l] [select]