Re: How to verify whether a directory exists

[B. Fongo]

I tried several alternatives to solve the problem, but failed. In most 
cases, the script couldn't create a directory if there is a text file 
with the same name. Rob's suggestion works better; except that it 
overrides the directory without warning - if it already existing. But it 
remians some how streng, because the content of the directory remains 
intact.

mkdir $dir || die "Failed to create $dir: $!\n" unless -d $dir;

It's okay anyway - as long as it's able to create a directory - even if 
a file (other than a directory) with the same name is found.

Thanks guys



Rob Dixon wrote:

Wiggins D'Anconia wrote:
 

B. Fongo wrote:
   

I want to use mkdir(blah blah, o777), but want to first find out
whether the directory "blah blah" exists.
I'm not if the -e option will bw right here. Let's say:
      unless (-e blah_blah) mkdir(blah_blah, 0777);
# Is this okay?
     

In general -e checks for file existence, -d checks to see if an existing
file is a directory (or complains that the file doesn't exist).
perldoc -f -e

So your above code leaves a condition, where blah_blah exists but is
*not* a directory which is likely to cause you problems. But since you
haven't told us what happens in this failure case it is hard for us to
say, but,
if (-e blah_blah) {
    unless (-d blah_blah) {
        die "File exists but is not directory";
    }
}
else {
    # don't forget to check mkdir's failure
    mkdir(blah_blah, 0777) or die "Can't make directory: $!";
}
   

Just a note:

There's no need to do a separate -e call to check whether a directory
exists, -d won't throw an error. A simple
 die "$dir is not directory" unless -d $dir;

Will check that $dir both exists and is a directory, which
is probably all that is needed.
Rob



 



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