I treid one of my previous example to pass input and output files via command line arguments using perl?
Previous example:
[Is it possible to add the file out in the File::Find::Rule using perl?
code which i tried to add input and output file as command line arguments:(generate.pl).I got struck how to include command line arguments to read and copy the files along with perl modules.
use strict;
use warnings 'all';
use CGI qw(:all);
#generate the user file arguments
use Getopt::Long 'GetOptions';
use File::Path qw( make_path );
use File::Copy qw( copy move);
use File::Find::Rule qw( );
GetOptions(
'prjroot=s' => \my $input_dir,
'outdir=s' => \my $output_dir,
);
my %created;
for my $in (
File::Find::Rule
->file()
->name(qr/^[^.].*\.yfg$/)
->in($input_dir)
) {
my $match_file = substr($in, length($input_dir) + 1);
my ($match_dir) = $match_file =~ m{^(.*)/} ? $1 : '.';
my $out_dir = $output_dir . '/' . $match_dir;
my $out = $output_dir . '/' . $match_file;
make_path($out_dir) if !$created{$out_dir}++;
copy($in, $out);
}
Error occured:
./generate.pl: line 1: use: command not found
./generate.pl: line 2: use: command not found
./generate.pl: line 3: syntax error near unexpected token `('
./generate.pl: line 3: `use CGI qw(:all);'
perl execution should be as follows:
I should copy the contents from one directory to another directory along with perl modulES(I.E File::Find::Rule)
./generate.pl -prjroot "/home/bharat/DATA" -outdir "/home/bharat/DATA1"
Help me fix my issues .
You miss the perl comment in the first line:
#!<path_to_perl>/perl
use strict;
use warnings 'all';
use CGI qw(:all);
#generate the user file arguments
.....
Your program will also work if you call it with the perl Interpreter in front of your command:
perl ./generate.pl -prjroot "/home/bharat/DATA" -outdir "/home/bharat/DATA1"
You've already seen what the problem is. But I'll just add that perldoc perldiag gives pretty good explanations for any error message you get from Perl. In this case, searching for "command not found" would give you this:
%s: Command not found
(A) You've accidentally run your script through csh or another shell instead of Perl. Check the #! line, or manually feed your script into Perl yourself. The #! line at the top of your file could look like
#!/usr/bin/perl -w
And that's particularly impressive, given that this error isn't actually generated by Perl - but by your shell.
Related
I am trying to implement a perl script and I need to get a directory of my executed file.
For example if my file that I'm executing is at C:\Scripts\MyScript.pl I would like to get C:\Scripts.
I tried dirname but it does not seem to do what i want. It just prints .
I understand that I need to use dirname and abs_path together, however abs_path seems buggy to me because it returns some UNIX looking directory and then concatenates it with the actual path which obviously is invalid path in the end.
Here is my proof of concept.
# The initial variable with file
say $0; # C:\Users\sed\AppData\Roaming\npm\node_modules\my-test-module\my-test-file
# This is just a current directory
say dirname($0); # .
# This looks like a bug to me, the shell is opened in C:/Users/sed so it is related
say abs_path($0); # /c/Users/sed/C:/Users/sed/AppData/Roaming/npm/node_modules/my-test-module\my-test-file
# This is what I need, except I don't need that first UNIX looking part
say dirname(abs_path($0)); # /c/Users/sed/C:/Users/sed/AppData/Roaming/npm/node_modules/my-test-module
A quick look at:
perldoc File::Basename
shows why it may not be the best choice for what you need to do.
Please try File::Spec instead.
C:\Users\Ken> echo C:\Scripts\MyScript.pl | perl -MFile::Spec -lne "print $_; ($v,$d,$f)=File::Spec->splitpath($_); print $v.$d;"
C:\Scripts\MyScript.pl
C:\Scripts\
Type:
perldoc File::Spec
for more information. BTW, I tested with Strawberry perl v5.24.1
use FindBin qw( $RealBin );
say $RealBin;
Common use:
use lib $RealBin;
or
use lib "$RealBin/lib";
Using Strawberry Perl v5.26.1 I found that starting the script directly as in MyScript.pl gave a different result to starting it with Perl i.e. perl MyScript.pl. In the latter case I got the useless relative (dot) output.
The following worked for me in both cases:
use File::Basename;
use File::Spec;
my (undef, $this_script_folder, undef) = fileparse(File::Spec->rel2abs( __FILE__ ));
I'm trying to open an input file as an argument using the Getopt::Long module
This is the beginning of my script
#! /usr/bin/perl -s
use strict;
use warnings;
use Data::Dumper;
local $Data::Dumper::Useqq = 1;
use Getopt::Long qw(GetOptions);;
my $input='';
GetOptions('input|in=s' => \$input);
open(my $table1,'<', $input) or die "$! - [$input]"; #input file
And this is how I launch the script
$ script.pl -in /path/to/file.txt
I get as output:
No such file or directory - [] at script.pl line 13.
Line 13 is the line with open(....
Is there a mistake in the script?
You are using Perl's built-in option parsing with the -s in your shebang line. In a command like script.pl -in /path/to/file.txt that makes perl set the variable $in to 1 and remove the corresponding entry from #ARGV before Getopt::Long ever sees it
Just remove -s from the shebang line and everything it will work for you
No, there is no mistake in the script. Your code is doing what you told it to do.
It's calling the die "$! - [$input]"; part of that line, because the open returned a false value.
No such file or directory is the content of $!. That's the error it encountered. And between the [] there is the value of $input, which is empty. So there's your problem. You're passing an empty string to open, and that fails.
You are calling it the wrong way.
Getopt::Long requires options that are longer than one letter to be prefixed by --. This means that -in should be --in.
$ script.pl --in /path/to/file.txt
Because you didn't do that, Getopt::Long didn't see your option, and didn't parse it. A bit higher you initialized $input = '', so it stayed the empty string.
You could add a check to make sure that the input file is always provided.
use strict;
use warnings;
use Getopt::Long qw(GetOptions);;
my $input = '';
GetOptions('input|in=s' => \$input);
die 'the --input option is required!' unless $input;
open(my $table1,'<', $input) or die "$! - [$input]"; #input file
I'm unable to execute the HTML::Template function in the CGI.
I'm following a simple tutorial that I found here: http://metacpan.org/pod/HTML::Template
I created a new file on my server in the home path as test.tmpl.
I created a new file named frt.cgi ... (is that the issue here? should it be a different file extention??)
#!/usr/local/bin/perl -w
use HTML::Template;
# open the html template
my $template = HTML::Template->new(filename => '/test.html');
# fill in some parameters
$template->param(HOME => $ENV{HOME});
$template->param(PATH => $ENV{PATH});
# send the obligatory Content-Type and print the template output
print "Content-Type: text/html\n\n", $template->output;
I've modified the 1st line to reflect my host provided program path for perl. I don't know what the -w does I just know I've tried this with and without it. Also I've tried changing the code a bit like this:
use warnings;
use strict;
use CGI qw(:standard);
use HTML::Template;
I've searched...
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE+&submit=search
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE
https://stackoverflow.com/search?q=HTML%3A%3ATEMPLATE+PERL&submit=search
Yet I still do not see the answer.
I even searched google for .TMPL Encoding because I thought there may be some special type needed. Please help.
If you look in your server logs, you'll probably see an error message along the lines of:
HTML::Template->new() : Cannot open included file /test.html : file not found.
You need to provide the path on the file system, not a URI relative to the generated document.
First, you likely specified the wrong path - change /test.html to test.html.
Also, it is possible that there is no $ENV{HOME} variable in your system so set up flag die_on_bad_params to 0:
my $template = HTML::Template->new(
filename => 'test.html',
die_on_bad_params => 0,
);
Also, don't forget to mark your Perl file as executable by chmod 755.
Option -w makes Perl to enable warnings, so there is no point to write use warnings; afterwards.
You can check what Perl command line options do by using module B::Deparse, like this ($^W variable disables/enables warnings):
perl -w -MO=Deparse -e "print;"
This would print:
BEGIN { $^W = 1; }
print $_;
i am trying to put some word in tempfile via commandline
temp file creat but word not past in tempfile
#!/usr/bin/perl -w
system ('clear');
$TMPFILE = "mktemp /tmp/myfile/devid.XXXXXXXXXX";
$echo = "echo /"hello world/" >$TMPFILE";
system ("$TMPFILE");
system ("$echo");
Please Help to Solve This
To capture the name output by mktemp, do this instead:
chomp($TMPFILE = `mktemp /tmp/myfile/devid.XXXXXXXXXX`);
But Perl can do all the things you are doing without resorting to the shell.
Avoid using external commands from perl script as much as possible.
you can use: File::Temp module in this case, see this
Here's a specific demonstration of the advice that others have given you: where possible, use Perl directly rather than invoking system. Also, you should get in the habit of including use strict and use warnings in your Perl scripts.
use strict;
use warnings;
use File::Temp;
my $ft = File::Temp->new(
UNLINK => 0,
TEMPLATE => '/tmp/myfile/devid.XXXXXXXXXX',
);
print "Writing to temp file: ", $ft->filename, "\n";
print $ft "Hello, world.\n";
Say I have this perl "program" called simple.pl:
#!/usr/bin/perl
use xyz; # xyz is bogus and doesn't exist
And I also have this "program", called simple2.pl:
#!/usr/bin/perl
system("simple.pl");
my $abc = `simple.pl`;
printf("abc %s\n", $abc);
for both system and backtick, I get this message:
Can't exec "simple.pl": No such file or directory at scripts/perl/simple2.pl line 7.
Can't exec "simple.pl": No such file or directory at scripts/perl/simple2.pl line 9.
Not very useful for the user calling simple2.pl. Is there a way to get a more useful message?
Note. simple.pl does exist in the current directory. The real problem is that simple.pl doesn't compile. simple2 responds by saying simple doesn't exist. it's a misleading message.
If I had a way to even capture the compile message that would be a start.
This means system couldn't find an executable named "simple.pl" on your PATH. If your simple.pl is in the current directory, you could try to change "simple.pl" to "./simple.pl".
Actually, I don't see how to make this message more descriptive. If you were perl, how would you report this error?
BTW, I wouldn't try to run "simple2.pl" from inside of simple2.pl :)
Yes, check to see if the file exists and is executable, and if it isn't, print a more descriptive message.
unless (-ex $filename) {
print "I am unable to execute file $filename.";
}
If perl say it can't find the file, then it can't find the file. And the problem is more your code. Look at this example.
sidburn#sid:~/perl$ cat test.pl
#!/usr/bin/env perl
use strict;
use warnings;
use xyz;
sidburn#sid:~/perl$ cat test2.pl
#!/usr/bin/env perl
use strict;
use warnings;
system('test.pl');
sidburn#sid:~/perl$ cat test3.pl
#!/usr/bin/env perl
use strict;
use warnings;
system('./test.pl');
If you execute test2.pl you get:
sidburn#sid:~/perl$ ./test2.pl
Can't exec "test.pl": No such file or directory at ./test2.pl line 4.
If you execute test3.pl you get:
sidburn#sid:~/perl$ ./test3.pl
Can't locate xyz.pm in #INC (#INC contains: /home/sidburn/perl510/lib/5.10.1/i686-linux /home/sidburn/perl510/lib/5.10.1 /home/sidburn/perl510/lib/site_perl/5.10.1/i686-linux /home/sidburn/perl510/lib/site_perl/5.10.1 .) at ./test.pl line 4.
BEGIN failed--compilation aborted at ./test.pl line 4.
If you don't provide a relative or absolute path then perl lookup the command in your $PATH environment variable. If it is not there it can't find the file.
You need to provide "./" if it is in the current directory. But note "current directory" doesn't mean the directory where your script relies.
If you want the later then you probably want to do a
use FindBin;
with this you can do something like this:
#!/usr/bin/env perl
use strict;
use warnings;
use FindBin;
use File::Spec::Functions;
my $exe = catfile($FindBin::RealBin, 'test.pl');
print $exe, "\n";
system($exe);
if you want to check if system returns correctly, you need to check the return value from the system() command or $? later that holds the value.
if ( $? != 0 ) {
die "Cannot execute $exe.\n";
}
if you want to suppress messages from your program you need to redirect STDOUT, STDERR before starting your program with system().
Or use something like IPC::System::Simple
Or IPC::Open3 (in the core).
Bonus points for enabling the warnings pragma! Have an upvote!
You want to use backticks or qx// to capture the output of an external program, not system. To substitute your own error message that will make sense to your users (more points for you!), then you might do something as in
#! /usr/bin/perl
use strict;
use warnings;
no warnings 'exec';
chomp(my $abc = `simple2.pl`);
if ($? == 0) {
printf("abc %s\n", $abc);
}
else {
die "$0: unable to calculate abc\n";
}
In case you're unfamiliar, $? is
$CHILD_ERROR
$?
The status returned by the last pipe close, backtick command, successful call to wait or waitpid, or from the system operator.
When $? is zero, it indicates success.
Remember that the warnings pragma is lexical, so rather than disabling the warning for the whole program, you might do it for just one sub:
sub calculate_abc {
no warnings 'exec';
# ...
}
If you are trying to execute something you know is a Perl script, why not invoke the interpreter directly rather than dealing with the system knowing how to execute the file?
my $file = 'simple.pl';
-e $file or die "file '$file' not found";
system "perl $file";
# or
print `perl $file`;
to run with the same installation of perl that is running your current script:
system "$^X $file"; # or `$^X $file`
$^X is a special Perl variable that contains the file name of the running interpreter.
I had the exact same issue and figured out that perl wasn't installed. So the bash script was trying to execute the perl without an interpreter.
ls /usr/bin/perl
Try specifying the full path to the "simple.pl" file.