I could not able to run the exe using perl code.
my $XSD = "C:\\IParser\\Iparser\.exe --xsds \"$dir\\$out\_xsd\.xml\"";
system($XSD);
The above $xsd run in commend prompt it will execute fine. when I run through perl source code it shows error as
the handle is invalid
I don't no what is the problem behind this. Please help.
This could be because of closed handles to STDIN, STDOUT and STDERR (or any of them). Most probably if you run this as a daemon or from service.
Try opening the standard handles before running the process (assuming you're on windows according to path):
open(STDIN, "<NUL");
open(STDOUT, ">NUL");
open(STDERR, ">NUL");
Related
Whew that is a long-winded title. But it explains my issue:
I have a crontab that runs a perl script.
That perl script runs a cap task, which outputs to STDOUT some status messages.
The perl script is supposed to capture the STDOUT (currently using backticks) from cap and parse it.
Now, this works 100% fine when I run the script from a bash user. However, when I run the script from a crontab, the perl script doesn't capture any output from the cap task.
Has anyone dealt with anything like this before? Thanks.
Maybe your cap executables are died without emitting any message to stdout. Did you checking the success state of execution?
Could you tried this?
$check_result = `$cmd 2>&1`;
if ($?){
die "$cmd failed with $check_result, $!";
}
I have written a Perl wrapper around a shell script. I am using IPC::Run::Simple to execute system commands. As an example:
run ("mkdir ~$usr/12.2.0_cp/faiz_cpv/$pdate") or die "Error $ERR";
run ("cp ~$usr/12.2.0_cp/faiz_cpv/MPlist.lst ~$usr/12.2.0_cp/faiz_cpv/$pdate") || die "Error: $ERR";
run ("cd ~$usr/12.2.0_cp/faiz_cpv/$pdate; sh /opsutils/mfg_top/rel/CPV/bin/list_generation.sh . MPlist.lst mfg_relall_us\#oracle.com") or die "error $ERR";
.
.
One of these shell scripts requires the user of the script to enter their password. That is, a message is printed on stdout and the password is accepted via the shell. A number of calls are made to this shell script during the entire process which means a user must reenter his password a number of times.
Is there a way by which I can request user for the password at the command line itself, and pass that password implicitly instead of prompting user for the password again and again?
Perl has mkdir and chdir built in and File::Copy provides a copy routine. Its generally safer and faster to use them than shelling out. Though it will not translate ~ for you. File::chdir makes changing a directory and running a command a little safer.
For the rest, use the full IPC::Run to control interacting with your program and Term::ReadLine::Gnu to read the password without displaying it. Sorry this is just a sketch and not a full answer.
Synopsis
I execute a shell command from Perl and when run from the command line it works, but when run in the debugger it does not work. Running it as a Win32::Daemon shows the same behaviour.
The Source Code
I execute a command either with backticks
print `$cmd`
or like this:
open FH, "$cmd |" or die "Couldn't execute $cmd: $!\n";
while(defined(my $line = <FH>)) {
chomp($line);
print "$line\n";
}
close FH;
The command reads like this:
$cmd = '"C:\path\to\sscep.exe" getca -f "C:\path\to\config\capi_sscep.cnf"'
Even creating a small test script that just executes this command does only work if run from command line.
The System
Windows x64
Active Perl v5.16.0, MSWin32-x64-multi-thread
Eclipse Juno 20120614-1722
What works
I works to open an administrator prompt (necessary for script execution) and to:
perl script.pl
Output gets printed to screen, $? is 0.
What does not work
Starting Eclipse and running a debug session with the same perl script.pl call.
Also not working is adding a service and executing the command (created with Win32::Daemon). The daemon itself is working perfectly fine and starting the perl script as expected. Only the command does not get executed. $? is 13568 or 53 if shifted with $? >> 8, no output gets printed. The exit code does not belong to the program.
Further Details
The tool I am calling is called sscep and is extended by me. It uses the OpenSSL API and loads the capi engine (Windows CryptoAPI). But the command itself does at least print output before any serious action starts. I can happily provide the source code for this, but I doubt it will help.
I was able to narrow this further down: The problem only exists in the combination of the Perl program (CertNanny) and the binary (sscep). Calling dir inside CertNanny works, calling sscep in a test Perl script works, too. So what could possibly be done in Perl to break a single binary from being called...?
Any ideas where this problem might originate from or how I can possibly narrow it down?
Here is what I believe the problem to be: when you run your program on the command line, the system() command goes through the shell (cmd.exe); when you run your program elsewhere, it does not. Unfortunately, the two methods handle command line arguments differently. Here is an article that seems like it should help you solve the problem.
In my experience, this sort of thing is a mess in Windows. I have had trouble with this issue in Perl, also.
I have a Perl script which I want to run every 4 hours through cron. But somehow it fails to execute through cron and runs fine if I run it through command line. Following is the command which I set in crontab:
perl -q /path_to_script/script.pl > /dev/null
Also, when I run this command on command prompt, it does not execute but when I go in the leaf folder in path_to_script and execute the file, it runs fine.
Also, where will the log files of this cron job be created so that I can view them?
You should probably change the working directory to "leaf folder".
Try this in your crontab command:
cd /path_to_script; perl script.pl >/dev/null
Wrt. log files. Cron will mail you the output. But since you sent stdout to /dev/null, only stderr will be mailed to you.
If you want the output saved in a log file, then pipe the stderr/stdout output of the script into a file, like so:
cd /path_to_script; perl script.pl 2>&1 >my_log_file
Usually cron will send you mail with the output of your program. When you're figuring it out, you probably want to check the environment. It won't necessarily be the same environment as your login shell (since it's not a login shell):
foreach my $key ( keys %ENV ) {
printf "$key: $$ENV{$key}\n";
}
If you're missing something you need, set it in your crontab:
SOME_VAR=some_value
HOME=/Users/Buster
If you need to start in a particular directory, you should chdir there. The starting directory from a cron job probably isn't what you think it is. Without an argument, chdir changes to your home directory. However, sometimes those environment variables might not be set in your cron session, so it's probably better to have a default value:
chdir( $ENV{HOME} || '/Users/Buster' );
At various critical points, you should give error output. This is a good thing even in non-cron programs:
open my $fh, '<', $some_file or die "Didn't find the file I was expecting: $!";
If you redirect things to /dev/null, you lose all that information that might help you solve the problem.
looks like you may have missed the
#!/usr/bin/perl
at the start of your perl script which is why you might need perl -q to run it
once you have added that line you can run it directly from the command line using
/path_to_script/script.pl
If you use a command in your perl program, i advise you to put the full path to the command in your program.
I have try to load environment but it is not more helpful.
After a oversee with one colleague, i think it's from interaction between perl and the system environment.
Best regards,
Moustapha Kourouma
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.