PERL Beginners - Error in Script

Author

Error in Script

Prabu

2004-04-04, 8:30 am

Hi,
I have wrote a script to search for a pattern and replace it in
all files of a directory,that i specified at commandline.
I want another one thing is to be done in the script.That's,it should
search only for the type of files I specified at commandline.
That is,it should get the extension of file name and search only those
files in the directory.

I have made a attempt in this script,but it goes on asking extension for
all the files in directory.
Plz help me in getting the things right in the following script.
Here I have use Split operator to get the extension of filename.

#! /usr/bin/perl

print "Enter a path name: ";
my $path=<STDIN>;
chomp($path);
opendir THISDIR, "$path" or die "serious dainbramage: $!";
my @allfiles = readdir THISDIR;

# get all files
foreach $file (@allfiles){
$filetoopen = $path ."/" .$file;

# filter to check the type of file
print "Enter the type of extension:";
my $ext=<STDIN>;
chomp($ext);
($str1,$str2) = split(/./, $filetoopen);
if($str2 eq $ext)
{
print $str2;
print $filetoopen;
open(IN, "<$filetoopen") || die "cannot open file\n";
open(OUT, ">$test") || die "cannot open file\n";
while (<IN> ){
if (/$com/){
s/$com/td>\n<\\script>/g;
}
if (/$img/){
s/$img/\n<script>\n<img/g;
}
if (/$pattern/){
s/$pattern/$own/g;
# print $_;
}
if (/img/){
s/$img/document.write("<img/g;
}
if (/$com/){
s/$com/td>");/g;
}
print OUT $_;
}
close (OUT);
close (IN);
rename("$test","$filetoopen");
}}

Thanks inadvance,
Prabu.

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Martin Lercher

2004-04-04, 8:30 am

That's 'cause you have put the question inside the foreach loop:
> # get all files
> foreach $file (@allfiles){
> $filetoopen = $path ."/" .$file;
>
> # filter to check the type of file
> print "Enter the type of extension:";
> my $ext=<STDIN>;

Btw, it would be easier to just use the fileglob operator from the start
(with a pattern of the form "path/*.ext"):

#! /usr/bin/perl

print "Enter a glob pattern:";
my $pattern=<STDIN>;
chomp($pattern);
my @files = glob ($pattern) ;
@files or die "serious dainbramage: $!";

foreach my $file (@files) {
print $filetoopen;
open(IN, "<$filetoopen") || die "cannot open file\n";
....

Martin

John W. Krahn

2004-04-04, 10:31 am

Prabu wrote:
>
> Hi,

Hello,

> I have wrote a script to search for a pattern and replace it in
> all files of a directory,that i specified at commandline.
> I want another one thing is to be done in the script.That's,it should
> search only for the type of files I specified at commandline.
> That is,it should get the extension of file name and search only those
> files in the directory.
>
> I have made a attempt in this script,but it goes on asking extension for
> all the files in directory.

That is because you are asking for the extension inside the loop. Just
ask before you enter the loop.

> Plz help me in getting the things right in the following script.
> Here I have use Split operator to get the extension of filename.
>
> #! /usr/bin/perl

use warnings;
use strict;

> print "Enter a path name: ";
> my $path=<STDIN>;
> chomp($path);
> opendir THISDIR, "$path" or die "serious dainbramage: $!";

perldoc -q vars

> my @allfiles = readdir THISDIR;
>
> # get all files
> foreach $file (@allfiles){
> $filetoopen = $path ."/" .$file;
>
> # filter to check the type of file
> print "Enter the type of extension:";
> my $ext=<STDIN>;
> chomp($ext);

Move the previous four lines outside of the foreach loop.

> ($str1,$str2) = split(/./, $filetoopen);

The . character is special in a regular expression, it matches all
characters except the newline character.

> if($str2 eq $ext)
> {
> print $str2;
> print $filetoopen;
> open(IN, "<$filetoopen") || die "cannot open file\n";
> open(OUT, ">$test") || die "cannot open file\n";

Where did $test come from? You are using $! in your opendir() error
message, you should use it here as well.

> while (<IN> ){
> if (/$com/){
> s/$com/td>\n<\\script>/g;
> }
> if (/$img/){
> s/$img/\n<script>\n<img/g;
> }
> if (/$pattern/){
> s/$pattern/$own/g;

Where did $com, $img, $pattern and $own come from? There is no need to
do a match before you do a substitution with the same regular
expression.

> # print $_;
> }
> if (/img/){
> s/$img/document.write("<img/g;
> }
> if (/$com/){
> s/$com/td>");/g;

You have already removed $img and $com above. What did you think these
substitutions would accomplish?

> }
> print OUT $_;
> }
> close (OUT);
> close (IN);
> rename("$test","$filetoopen");

perldoc -q vars

You should verify that rename() succeeded.

> }}

----------------------------------------

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

print 'Enter a path name: ';
chomp( my $path = <STDIN> );

print 'Enter the type of extension: ';
chomp( my $ext = <STDIN> );

opendir THISDIR, $path or die "serious dainbramage: $!";
my @allfiles = map "$path/$_", grep /\Q$ext$/, readdir THISDIR;

# get all files
foreach my $filetoopen ( @allfiles ) {

print $filetoopen;
open IN, "<$filetoopen" or die "cannot open file: $!";
open OUT, ">$test" or die "cannot open file: $!";

while ( <IN> ) {
s/$com/td>\n<\\script>/g;
s/$img/\n<script>\n<img/g;
s/$pattern/$own/g;
s/$img/document.write("<img/g;
s/$com/td>");/g;
print OUT $_;
}
close OUT;
close IN;
rename $test, $filetoopen or warn "Cannot rename $test to
$filetoopen: $!";
}

__END__

John
--
use Perl;
program
fulfillment

David Kirol

2004-04-05, 6:30 am

You'll need to fix this also
> ($str1,$str2) = split(/./, $filetoopen);
It should be:
($str1,$str2) = split(/\./, $filetoopen);
So that split can funcrion as you expect.

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