http://www.perlmonks.org?node_id=897551

sashawn has asked for the wisdom of the Perl Monks concerning the following question:

Hello, I have a file with name: PPSFAR65_DKMAR_CUST_QUERY-3865422.xls. Everyday it needs to be renamed to PPSFAR65_DKMAR_CUST_QUERY.xls. It was working fine till I started getting couple more files: PPSFAR66_MARBS_CUST_QUERY-3865420.xls and PPSFAR67_PMNT_ON_SIS_INVC-3865419.xls. With the addition of the new files, even though I pass parameter, PPSFAR65_DKMAR_CUST_QUERY.xls, it goes and updates file PPSFAR67_PMNT_ON_SIS_INVC-3865419.xls as that is the latest file. Here is code I have: 
#!/usr/bin/perl
# Syntax : /../perl /.../PS_file_Rename.pl -s /..../Source_directory -
+f filename.xls
#    .. -> path of Perl.exe
#   ... -> path of the script PS_file_Rename.pl
# -s option - Source_Folder
# -f option - Filename to use for renaming
use Getopt::Std;
use Data::Dumper;
use POSIX qw(strftime);
use vars qw($opt_s $opt_f);
getopts('s:f:');
$ff="$opt_s"."\\"."$opt_f";
#if the file name already exists delete it
if (-e $ff)
{
       unlink($ff) or  warn scalar localtime(time()), " WARN Can't del
+ete $ff : $!";
}
my $path =  $opt_s."\\*.*";
$path =~ s|\\|/|g;
#find the newest file
my $newestfile = (sort{(stat $b)[10] <=> (stat $a)[10]}glob $path)[0];
#rename the newest file to the name passed
rename($newestfile,$ff) or  warn scalar localtime(time()), " WARN Can'
+t rename $newestfile : $!";
@files = glob $opt_s."\\*.*";
foreach my $file (@files)
{
    if($file ne $ff)
   {
       unlink($file) or  warn scalar localtime(time()), " WARN Can't d
+elete ".$opt_s."\\".$file." : $!";
  }
}

[download]

Replies are listed 'Best First'.
Re: Rename file
by wind (Priest) on Apr 05, 2011 at 17:04 UTC

    Perl::Tidy to the rescue.

    Here's the code in a slightly more readable format. Will let other monks carry the torch from here:

    #!/usr/bin/perl
# Syntax : /../perl /.../PS_file_Rename.pl -s /..../Source_directory -
+f filename.xls
# .. -> path of Perl.exe
# ... -> path of the script PS_file_Rename.pl
# -s option - Source_Folder
# -f option - Filename to use for renaming

use Getopt::Std;
use Data::Dumper;
use POSIX qw(strftime);

use vars qw($opt_s $opt_f);

getopts('s:f:');
$ff = "$opt_s" . "\\" . "$opt_f";

#if the file name already exists delete it
if ( -e $ff ) {
    unlink($ff)
      or warn scalar localtime( time() ), " WARN Can't delete $ff : $!
+";
}
my $path = $opt_s . "\\*.*";
$path =~ s|\\|/|g;

#find the newest file
my $newestfile = (sort {(stat $b)[10] <=> (stat $a)[10]} glob $path)[0
+];

#rename the newest file to the name passed
rename( $newestfile, $ff )
  or warn scalar localtime( time() ), " WARN Can't rename $newestfile 
+: $!";
@files = glob $opt_s . "\\*.*";
foreach my $file (@files) {
    if ( $file ne $ff ) {
        unlink($file)
          or warn scalar localtime( time() ),
          " WARN Can't delete " . $opt_s . "\\" . $file . " : $!";
    }
}

    [download]
[reply]
[d/l]
      thank you for making readable...this is my first time post here...messed it up...
[reply]

        No problem. You can and should simply go back and edit your original post. Follow the basic example in this faq on how to add formatting using <p></p> and <code></code> tags: How do I post a question effectively?

        Additional formatting tags are available here, Perl Monks Approved HTML tags, but the former are all one normally ever needs. You can even use the reformatted text that I provided in your original post.

        Each of these faqs are linked to below the textarea where one posts a question. There are other resources available there too.

        Finally, one caveat is that you should add an "Update" note at the bottom of your post whenever you make a change. Especially to a question node.

[reply]
Re: Rename file
by jpl (Monk) on Apr 05, 2011 at 17:36 UTC

    Your comments pretty much say it all 

      my $path = $opt_s . "\\*.*";
  $path =~ s|\\|/|g;

  #find the newest file
  my $newestfile =
   (sort {(stat $b)[10] <=> (stat $a)[10]} glob $path)[0];

    [download]

    You are globbing over all files with extensions in $opt_s, and finding the newest. You need to restrict attention to those matching everything up to the extension in $opt_f. (Left as an exercise). I cringe a bit at re-invoking stat() for each comparison. If you simply read the $opt_s directory, and keep track of the latest file matching the $opt_f pre-extension, you can fix the problem and save a lot of stat()s. (Perhaps those are the only files you want to remove, too... hard to know from your description).

[reply]
[d/l]
      hi...there will always be files only with extension, .xls i agree that right now,script is finding latest file instead of matching to $opt_f pre-extension. How can I match to that? I was actually trying to match that but didn't had success. Existing file is: PPSFAR65_DKMAR_CUST_QUERY-3865422.xls my $opt_f value will be PPSFAR65_DKMAR_CUST_QUERY.xls. i appreciate your suggestions. thank you.
[reply]
Re: Rename file
by jethro (Monsignor) on Apr 05, 2011 at 16:53 UTC
    Your post is unreadable. Edit it and use <p> for formatting paragraphs and put <code> tags around any code.
[reply]

Back to Seekers of Perl Wisdom