trying to rename filenames and extensions then add a header in line1 of each file

[jonathan184]

trying to rename filenames and extensions then add a header in line1 of each file

if the header existed in line 1 to go to the next file.

but i am getting error explciti errors

Here is my code I am using

#!/usr/bin/perl
 
user warnings;
use strict;
use Tie::File;
 
 
opendir(DIR, ".") or die $!;
 
my @files = readdir(DIR); # reads everything in the dir
close(DIR);    #
 
$i = 1;    #declared variable
# While loop implemented with the array
while (@files) {
 
   @row = split(/\./,$_); # will return each line listed in the read  filename. ext - or whatever is listed
 
   $name = $row[0];    # will read everything on the left of the . meaning will read the file name alone
   chomp($name);
 
   $new_name = $name.$i.'.txt' # The new name variable is declared so that the the filename left of the. will include the $i ands concatnate then end in .txt
   rename($_, $new_name);    # will return filename, ==> which will rename to the newname in the variable above.
 
   $i++;
 
################ Adding line 1 - Header information for each file that does not have it###############
 
 
tie @files, 'Tie::File', '$new_name' || die "Can't open: $!\n";
$numrows = @files;
 
$insertpoint = $numrows - 1;
$newrec="PARTY_UID|NAME|ADDR_ADDR|ADDR_ADDR_LINE_2|ADDR_ADDR_LINE_3|ADDR_ADDR_NAME|ADDR_ZIPCODE|ADDR_POBOX|ADDR_CITY|ADDR_PROVINCE|ADDR_COUNTRY|MAIN_PH_NUM|MAIN_FAX_PH_NUM|LANG_ID|X_VAT_NUM|TAX_JURIDICTION_CODE|ACCOUNT_GROUP|COMPLETE_DELIVERIES|INCO_TERMS1|INCO_TERMS2|CUSTOMER_GROUP|CUSTOMER_GROUP3|CUSTOMER_GROUP5|PRICE_LIST_TO_USE|SALES_ORG|BASE_CURCY_CD|PAY_TERM_NAME|CREATED|CREATED_BY|TAX_EXEMPT_FLG|X_PPL_HOLD|X_PPL_HOLD_DATE|X_CREDIT_HOLD
";
splice @rows, $insertpoint, 0, $newrec;
untie @rows; 
 
 
};

[rickumali]

. . . add a header in line1 of each file . . . if the header existed in line 1 to go to the next file.

Hello! I'm only going to tackle this first "requirement." I'd approach this without loading the entire file contents into an array, and using splice. Instead, I'd do something like this:

$line_count = 0;
while (<>) {
    $line_count++;
 
    if ($line_count == 1) {
        # First line. Check if header row exists using fancy Perl RE
 
        if (!/^HEADER$/) {
            print "HEADER\n";
        }
    }
    print;
}
 

As you can see, all the action happens when the program sees the first line. In the first line, if the HEADER row is not present, then print it. If the HEADER row is present, then don't print it.

I copied the above into a small Perl program file, and ran it locally (in Cygwin).

21:40:34 575> cat -n /tmp/newfile.txt
     1  HEADER
     2  This
     3  is
     4  a
     5  sample
     6  file.
 
21:40:39 576> perl addheader.pl </tmp/newfile.txt           
Processed 6 lines.
HEADER
This
is
a
sample
file.
 
21:41:27 579> cat -n /tmp/oldfile.txt 
     1  This
     2  is
     3  a
     4  sample
     5  file without the header row.
 
21:41:57 581> perl addheader.pl </tmp/oldfile.txt 
Processed 5 lines.
HEADER
This
is
a
sample
file without the header row.
 

I spend plenty of time in front of huge files (on the order of 500 to 1000 megabytes), and I try to avoid slurping in a large file into an array if I can help it. For this operation (adding a header row), it makes sense tackle it in a "streaming" fashion.