I have the following code in my perl script which obviously generates a csv file:
open(OUTPUT,">Test.csv");
When I click on the perl script, it generates the output file.
But when I call this script from a command prompt or C# or JAVA, SQL Script (xp_cmdshell), the script does not generate the output file.
I already have full permission for EVERYONE on the folder.
You don't check the success of the operation. Everytime use
open OUTPUT, '>', 'Test.csv' or die $!;
or turn on autodie.
Related
I am trying to execute a perl script to delete file1.txt in a directory.
When I execute the perl script using command prompt, I faced an error : Use of uninitialized value in chdir at C:/Debug/test.pl line 7.
Example:
C:\Debug>test.pl C:\Debug
However if I invoke perl in front of test.pl, the perl script is executed successfully and file1.txt was deleted.
Example:
C:\Debug>perl test.pl C:\Debug
Please find test.pl code as follow:
use strict;
use warnings;
use File::Copy;
my ($working_dir) = #ARGV;
chdir $working_dir or die "Can't change directory$!";
unlink "file1.txt";
I have mks_toolkit v8.7.5 with perl.exe installed. The .pl extension is associated with "C:\Program Files (x86)\MKS Toolkit\mksnt\perl.exe" "%1" %*.
I have no problem execute hello.pl (Hello World) without invoking perl in front of it.
Example:
C:\Debug>hello.pl
Anyway, users who face this problem can try to check the properties of your file, make sure the file is not read only and has full admin access.
I am working on a cgi script where I get an uploaded an audio file, downsample it to 8000Hz and then get it recognised later.
I am facing an error while downsampling the file. The code for downsampling goes like:
1) Code for File Upload:
use CGI;
use strict;
use File::Copy qw(copy);
use CGI::Carp 'fatalsToBrowser';
my $PROGNAME = "file_upload.cgi";
my $cgi = new CGI();
print "Content-type: text/html\n\n";
my $upfile = $cgi->param('upfile');
# Get the basename in case we want to use it.
my $basename = GetBasename($upfile);
no strict 'refs';
if (! open(OUTFILE, ">../cgi-bin/upload/".$basename) ) {
print "Can't open for writing - $!";
exit(-1);
}
2)Code for downsample:
my $source_file="/var/www/cgi-bin/upload/$upfile";
system("sox $source_file -r 8000 /var/www/cgi-bin/upload/temp.wav".";"."mv /var/www/cgi-bin/upload/temp.wav $source_file");
where:
source_file is the path for uploaded audio file
$upfile is the name of the uploaded wav file
temp.wav is the temporary downsampled file which is overwritten on the original file using mv command
Error
sox FAIL formats: can't open input file `/var/www/cgi-bin/upload/file1.wav': WAVE: RIFF header not found
file1.wav is the file I uploaded
Please help me understand why the sox command is not executing despite it being correctly written?
This isn't really an answer to your question as we don't have enough information yet.
Have you tried running the command from your Unix command line? I'd assume you get the same error. What do you get if you run file on the file that you have saved? How big is the file before and after you upload it?
You don't show the code that writes the uploaded file. I suspect there's a bug in that. If you add that to your question, we could help you find it.
Where is GetBasename() defined? Can we see the code?
Your sox command seems strange. You're running sox on a file called temp.wav and then copying that file over your uploaded file. Perhaps there are a couple of steps that you aren't telling us.
Some other suggestions for improvement:
Use cgi->new, not new CGI. The latter has some strange corner cases that you will have real problems debugging if you ever come across them.
If you're loading the CGI module, then why not use its header method instead of writing your own (technically incorrect) header.
no strict 'refs' is a really bad idea (and, as far as I can see, isn't needed here).
Please use the three-arg version of open() and lexical filehandles
open my $out_fh, '>', "../cgi-bin/upload/$basename"
Include the file path in your error message
my $file = "../cgi-bin/upload/$basename";
if (!open my $out_fh, '>', $file) {
print "Can't open file '$file' for writing - $!";
exit(-1);
}
You are loading the File::Copy module, but then moving your file using a shell command.
Allowing random users to upload files into a directory under your cgi-bin directory is a massive potential security hole. You should find another directory to store the uploaded files.
Oh, and then there's the whole - why on Earth would you be writing CGI programs in 2017!
The issue is resolved. The reason why I was having problem executing the sox and copy commands was because of where I was placing the two commands in code. Basically a beginners error. So I was opening the file as mentioned in the problem statement. I put the copy and sox commands for execution before I closed the filehandler and hence they were not getting executed successfully.
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 need to write a script that opens a file then closes it then opens it again. For example:
#!/usr/bin/perl
open(File,">>test.csv");
print File "1234\n";
close(File);
open(File,">>test.csv");
print File "5678\n";
close(File);
when this code runs on eclipse , it works fine but when I try running the script from the cmd; the file is opened for the first time only and the csv file contains 1234 only.
Probably you keep open the file somewhere.
To know this kind of error, you have to use "die" command with "open" as follows,
open(File,">>test.csv") || die $!;
This will throw you error if any (like Permission denied at line 1.).
Also it is recommended to use 'use strict;' and 'use warnings;' at top of the program to notify any error.
As I am still new to Unix and Perl, I'm finding a simple and direct method to grab the Unix command that I had run using Perl script.
What I know is "history" can track back the commands that I had run, but it is not working in Perl using back ticks history to run it.
I tried to put "history > filename" in vi text editor in a temporary file, use command "source" it, and it works, but command "source" also not working in Perl script using back ticks.
Can anyone guide me about my problems? direct me to correct method to solve my problems? T.T
Thanks.
You can't. Shells (well, bash and tcsh, anyway, your shell might, but probably doesn't, vary) only save command history in interactive mode. Commands run in a subshell by a perl script won't be added to the history file.
This will get the history of commands that were run by the user in interactive mode:
$data_file = "~/.bash_history";
open(DAT, $data_file) || die("Could not open file!");
#fileData = <DAT>;
close(DAT);
foreach $command (#fileData) {
# Do things here.
}
As mentioned by Wobble, though, this history file will not include commands run from a Perl script - you'll have to have the script append the command to a file when it runs it, thus creating it's own history file (or, append it to ~/.bash_history, which will have it share the history file with interactive shells).
If you have access to the perl script (that is, you can change it), you can simply write each command run in the perl script to a chosen text file:
sub run_program
{
my $program = shift;
open PROGS, ">>my-commands.txt", or die $!;
print PROGS $program."\n";
`$program`;
close(PROGS);
}
then just run `run_program($command) every time you wish to run a command in the script.