Very new to Perl. Running Perl on Padre and Windows 10 OS.
The script from my book is written for Unix. I don't know how to correct it so that it works with Windows.
Here is the script as written in my book (FOR UNIX):
use warnings;
#write to a file with a filehandle. Sriptname: file.handle
my $file="/home/jody/ellie/perl/newfile";
open(my $fh, ">", $file) || die "Can't open newfile: $!\n";
print $fh "hello world.\n";
print $fh "hello world again.\n";
At the command line
$perl file.handle
$cat newfile
the output should be looking like this:
hello world.
hello world again.
I made the following changes but with no success
use warnings;
#Write to a file with a filehandle. Scriptname: file.handle
my $file='C:\newfile.txt';
open (my $fh, ">", $file) || die "Can't open newfile: $!\n";
print $fh "hello world.\n";
print $fh "hello world again.\n";
When I run script I get the following output:
can't open newfile: permission denied**
When I run the script with debug I get the following information:
uncaught exception for user code
can't open newfile: permission denied
at handlingfiles.pl line 5
press any key to continue
What am i doing wrong?
As #choroba mentioned in a comment, C:\newfile.txt will [try to] write to the Windows root directory (e.g. C:\). So, you probably want just newfile.txt.
Cygwin: If you're using the perl that comes with cygwin, you can probably use /home/jody/newfile.txt as this perl supports the POSIX file syntax. If you installed cygwin at (e.g.) D:\cygwin, then the /home directory will end up in D:cygwin\home. Note you do ls /home to see what users have been defined.
Otherwise, if you want a full path, what is the full path for your .pl script. Obviously, you could write to that directory.
Side note: I've been writing perl for many years and on those rare occasions when I do use it on Windows, I vastly prefer using the cygwin version [that also has many scripts, tools, etc. and functions like a POSIX environment]. YMMV
Perl is asked to open the file for writing, so that is what it does. On Windows, normal users cannot write to the root directory of a drive, and Windows rejects its request. Try something like C:\Users\User\My Documents\newfile.txt.
Related
I just created a text test.conf file with some information. How can I read it on Perl?
I am new to Perl and I am not sue would will I need to do.
I tried the following:
C:\Perl\Perl_Project>perl
#!/usr/local/bin/perl
open (MYFILE, 'test.conf');
while (<MYFILE>)
{ chomp; print "$_\n"; }
close (MYFILE);
I tried installing Perl on my laptop that has Windows 7 OS, and using command line.
Instead of using command line, write your program in a file (you can use any editor to write your program, I would suggest use Notepad++) and save as myprogram.pl in the same directory where you have your .conf file.
use warnings;
use strict;
open my $fh, "<", "test.conf" or die $!;
while (<$fh>)
{
chomp;
print "$_\n";
}
close $fh;
Now open a command prompt and go to the same path where you have your both file myprogram.pl and test.conf file and execute your program by typing this:
perl myprogram.pl
You can give full path of your input file inside program and can run your program from any path from command prompt by giving full path of your program:
perl path\to\myprogram.pl
Side note: Always use use warnings; and use strict; at the top of your program and to open file always use lexical filehandle with three arguments with error handling.
This is an extended comment more than an answer, as I believe #serenesat has given you everything you need to execute your program.
When you do "command line" Perl, it's typically stuff that is relatively brief or trivial, such as:
perl -e "print 2 ** 16"
Anything that goes beyond a few lines, and you're probably better off putting that in a file and having Perl run the file. You certainly can put larger programs on the command line, but when it comes to going back in and editing lines, it becomes more of a hassle than a shortcut.
Also, for what it's worth the -n and -p parameters allow you to process the contents of a stream, meaning you could do something like this:
perl -ne "print if /oracle/i" test.conf
I'm at my first attempt to use mod_perl. I'm totally new to it. I opted for ModPerl::PerlRun because I don't want to make any modification to the scripts I already have
I followed the instructions in Installing Apache2/Modperl on Ubuntu 12.04
I uploaded script.pl to /perl, and the script looks like it's running fine except for this
open(my $fh, '<:encoding(UTF-8)', 'page_template.htm') or die $!;
It won't open the file and dies with the message
No such file or directory at /var/www/perl/script.pl
Update
Note that the documentation for ModPerl::PerlRun has this to say
META: document that for now we don't chdir() into the script's dir, because it affects the whole process under threads.
so it is probably not workable to simply do a chdir in your program's code, and the second option below should be used
Original*
The current working directory of your CGI program isn't what you think. It is most likely to tbe the root directory /
You can either use chdir to set the working directory of the script
use File::Basename 'dirname';
chdir dirname(__FILE__);
or simply add the full path to the name of the file that you want to open, for instance
open my $fh, '<:encoding(UTF-8)', '/perl/page_template.htm' or die $!;
Note that you can't use FindBin, as your program is being run as a subroutine of Apache's main mod_perl process, so $FindBin::Bin will be equal to the directory of the Apache executable httpd and not of your own program file
I am beginner to Perl and I have to create a .pl file and I have folder containing near about 30 exe files(inside Folder1 in G:\Folder1). All of them must be executed by click to the .pl file.
My try is :
use strict; use warnings;
use autodie; # automatic error handling
while (defined(my $file = glob 'C:\shekhar_Axestrack_Intern*.exe'))
{
open my $fh, "<", $file; # lexical file handles, automatic error handling
while (defined( my $line = <$fh> )) {
do system $fh ;
}
close $fh;
}
Please let me know if my logic correct ? Could some one please correct me if i am wrong ?
Use system to execute an exe:
while (my $file = glob 'C:\shekhar_Axestrack_Intern\*.exe') {
system $file;
}
In addition, I have the feeling that you meant to write 'C:\shekhar_Axestrack_Intern*.exe'
instead of 'C:\shekhar_Axestrack_Intern*.exe'.
I think pl2bat may help you. It allows you to wrap Perl code into a batch file.
BTW why are you using echo in your Perl script? You should use print.
Edit: You have edited your question and now you want to know how to run all exe files from a folder using Perl?
Use the system command to run the exe files providing the full path.
See: How to run an executable file using Perl on Windows XP?
Edit 2: do system $fh ; This is not how you do it, please get a book (I'd suggest Beginning Perl by Ovid) and start learning Perl.
I am working on a simple perl program for my first assignment in my programming class. I literally have been stuck on this first part for more than a day. I cannot get my program to simply open a text file that is in the same directory as the program.
#!/usr/bin/perl -w
use strict;
my($fileName, $line);
print "Please enter name of file to be opened: ", "\n";
$fileName = <STDIN>;
chop($fileName);
#Associates FILE filehandle with the file: "filename.txt"
open(FILE, $fileName) or die("Can't open '$fileName': $!");
while(my $line = <FILE>){
print $line;
}
I am using strawberry perl. To run the program I am dragging and dropping the program into the command line to get the address of the program. It then attempts to run it.
It initially gave me a readline on closed filehandle error, and then I included the or die("Can't open '$fileName': $!"); portion of the code.
Now it says that there is no such file at the directory, but I know that the test.txt file is there because I just created it.
Picture of the code results: http://imgur.com/R8s7FFE
File directory that shows locations of my files: http://imgur.com/nUfM4lA)
The prompt is showing C:\Users\jacjar\Documents as the current working directory
So this is where the program will look for test.txt
But it is not in that directory
text.txt is in L:\College\Junior Year\1st Semester\COSC 320 (Programming Languages)
Move your test.txt file to the C: path shown above and it will work
Do you realize you are trying to open C:\User\jacjar\Documents\test.txt?
Guys im really confused now. Im new to learning Perl. The book ive read sometimes do Perl codes and sometimes do Linux commands.
Is there any connection between them? (Perl codes and linux commands)
I want to open multiple files using Perl code, i know how to open a single file in Perl using:
open (MYFILE,'somefileshere');
and i know how to view multiple files in Linux using ls command.
So how to do this? can i use ls in perl? And i want to open certain files only (perl files) which dont have file extension visible (I cant use *.txt or etc. i guess)
A little help guys
Use system function to execute linux command, glob - for get list of files.
http://perldoc.perl.org/functions/system.html
http://perldoc.perl.org/functions/glob.html
Like:
my #files = glob("*.h *.m"); # matches all files with a .h or .m extension
system("touch a.txt"); # linux command "touch a.txt"
Directory handles are also quite nice, particularly for iterating over all the files in a directory. Example:
opendir(my $directory_handle, "/path/to/directory/") or die "Unable to open directory: $!";
while (my $file_name = <$directory_handle>) {
next if $file_name =~ /some_pattern/; # Skip files matching pattern
open (my $file_handle, '>', $file_name) or warn "Could not open file '$file_name': $!";
# Write something to $file_name. See <code>perldoc -f open</code>.
close $file_handle;
}
closedir $directory_handle;