There is a small perl script using Net:SSH2 module
#!/usr/bin/perl
use strict;
use warnings;
use Net::SSH2;
my $ssh2 = Net::SSH2->new();
$ssh2->connect('testhost') or die $!;
if ($ssh2->auth_publickey('admin', 'id_rsa.pub', 'id_rsa')) {
print "Connected\n";
} else {
print "failed";
}
my $sess = $ssh2->channel() or die "Unable to create chan\n";
$sess->blocking(1);
$sess->shell();
print $sess "sudo /root/remote.pl\n";
print "$_\n" while <$sess>;
$sess->send_eof;
$sess->close;
After executing this, sometimes I see output of /root/remote.pl and sometimes I don't. I believe that the problem is in output buffering, but I don't how to solve this.
If this script is used on a linux system, why not using perl back-tilt to use linux commands instead of using a module?
Example:
#!/usr/bin/perl
use strict;
use warnings;
# Command
my $cmd = "ssh login:password#host; sudo /root/remote.pl; exit";
# Execute the command
`$cmd`
PS: if the remote.pl script has some print, you should see them.
Related
I wrote a routine to "safely" execute some command, and I wanted to capture STDOUT and STDERR in string variables using open(STDOUT, '+<', \$stdout) and similar for STDERR.
I verified via print "Test\n" and print STDERR "Test2\n" that the redirection works inside the routine (I can find the outputs in $stdout and $stderr).
However when I run the command through system() (Perl's version), the output still goes to the terminal.
So I wonder: Is opening a scalar value available for Perl's own I/O only?
And if so, how would I capture the STDOUT and STDERR from the system() call without using temporary files (having their own issues)?
(I've seen https://stackoverflow.com/a/109672/6607497 already)
The preferred solution (if such exists) should use as few extra packages as possible, and it should run with SLES 12 or SLES 15 (openSUSE Leap 15.2).
Those distributions only offer a limited set of Perl modules.
You can easily do this using IPC::Run to capture output.
Test script that writes to standard output and error:
#!/bin/sh
# demo.sh
echo "To Standard Output"
echo "To Standard Error" >&2
and perl script that runs it:
#!/usr/bin/env perl
use warnings;
use strict;
use IPC::Run qw/run/;
my ($out, $err);
run ["sh", "demo.sh"], \undef, \$out, \$err;
print "Standard output: ", $out;
print "Standard error: ", $err;
gives the following output:
$ perl demo.pl
Standard output: To Standard Output
Standard error: To Standard Error
Alternative using IPC::Run3 (Which might be more desirable if you don't need any of IPC::Run's more advanced features):
#!/usr/bin/env perl
use warnings;
use strict;
use IPC::Run3;
my ($out, $err);
run3 ["sh", "demo.sh"], \undef, \$out, \$err;
print "Standard output: ", $out;
print "Standard error: ", $err;
#!/usr/bin/perl
use strict;
use autodie;
use Capture::Tiny 'capture_merged';
my $ID=732636;
my $User="vispsh1";
my $Password="monitor1";
print "viewing item...\n";
open (my $file, '>', 'output.xls') or die "cannot open file";
my $mks_cmd="im viewissue --user='$User' --password='$Password' $ID";
print $file capture_merged { system($mks_cmd)};
# print $mks_cmd;
print "Done\n";
This is my script, the file is created but, it is not redirecting anything to output.xls, i can do it by using below command
C:\perl>perl -w mks.pl > sample.xls
but, i want to do it through the script to automate it fully!
Please help, Thankyou.
I have a perl script and its been executing from "/root/pkt/sw/se/tool" path and would need the complete directory path inside the script.
Can you please let me know how would i get the complete path?
sample.pl
our ($tool_dir);
use strict;
use warnings;
BEGIN {
$tool_dir = $0;
my $home_path = $tool_dir
$home_path =~ s|\w*/\w*/\w*$||;
my $target_path ="obj/Linux-i686/usr/share/ddlc/lib";
$lib_dir = "$home_path$target_path";
unshift(#INC, $lib_dir);
}
And i am executing this script from "pkt/sw/se/tool" path but here i am getting only "pkt/sw/se/tool" instead of "/root/pkt/sw/se/tool"
my perl script is available under /root/pkt/sw/se/tools/sample.pl
You can use the CWD module (http://perldoc.perl.org/Cwd.html) (code take from that page)
use Cwd;
my $dir = getcwd;
use Cwd 'abs_path';
my $abs_path = abs_path($file);
or you could execute the pwd command
$cwd = `pwd`;
If you just want the directory, not the full path, you could check out an existing answer at Print current directory using Perl
Use one of the modules already mentioned, never use backticks - unless you fully understand the risks and implications of doing so. If you do want to run 'pwd' then call it via something like IPC::Run3.
Examples:
#!/usr/bin/perl
use strict;
use warnings;
use Cwd;
use IPC::Run3;
# CWD
my $working_dir_cwd = getcwd;
print "Woring Dir (Cwd): $working_dir_cwd\n";
# IPC::Run3
my ($in, $out, $err);
my #command = qw/pwd/;
run3 \#command, $in, \$out, \$err or die $?;
print "Working Dir (pwd): $out\n";
You can use FindBin to locate directory of original perl script.
use FindBin;
use lib "$FindBin::Bin/../../../obj/Linux-i686/usr/share/ddlc/lib";
So I have:
test.pl > test.log
is there a way to know inside test.pl that I am outputing to 'test.log'? At the end of my script I want to do some manipulation of test.log without hardcoding the name.
Maybe. The following works on Linux, but will not be very portable to other systems...
#!/usr/bin/env perl
use strict;
use warnings;
my $out = readlink("/proc/$$/fd/1");
print STDERR "I am being output to $out\n";
Naturally, this is probably a bad idea. Better to explicitly open the file and write to it in Perl, rather than having the shell set up redirections.
You can redirect standard output from perl, with minimal changes to your script,
test.pl test.log
my ($file) = #ARGV;
if (#ARGV) {
open STDOUT, ">", $file or die $!;
}
print "output is redirected to $file\n";
# use $file at the end
Is there any method to execute foo2.pl from foo1.pl in Perl, and append the foo2.txt to the foo1.txt then create foo3.txt? thanks.
i.e.
foo1.pl
print "Hello"; # output to foo1.txt;
foo2.pl
print "World"; # output to foo2.txt;
How to create foo3.txt file based on foo1.pl.
foo3.txt
Hello
World
Something like append foo2.txt to foo1.txt.
As i know, I can open foo1.txt and foo2.txt, then include the lines in foo3.pl.
print FOO3_TXT (<FOO1_TXT>);
print FOO3_TXT (<FOO2_TXT>);
Is there any good method?
Update my test (ActivePerl 5.10.1)
My foo.pl
#!C:\Perl\bin\perl.exe
use strict;
use warnings;
print "world\n";
my hw.pl (foo.pl and hw.pl at the same directory)
#!C:\Perl\bin\perl.exe
use strict;
use warnings;
print 'hello ';
print `./foo.pl`;
Output
**D:\learning\perl>hw.pl
hello '.' is not recognized as an internal or external command,
operable program or batch file.**
If hw.pl updated {}:
#!C:\Perl\bin\perl.exe
use strict;
use warnings;
print q{hello }, qx{./foo.pl};
Now Output. (a little different for the loacation of hello)
D:\learning\perl>hw.pl
'.' is not recognized as an internal or external command,
operable program or batch file.
hello
[Update].
Fixed. see answer,
run this as a script
perl foo1.pl > foo3.txt;
perl foo2.pl >> foo3.txt;
contents of foo1.pl
!#/bin/perl
print "Hello";
contents of foo2.pl
!#/bin/perl
print "World";
or
simply use the cat command if you are running linux to append foo2.txt to foo1.txt.
Just in case you are being literal about execute foo2.pl from foo1.pl in Perl then this is what you can do:
print 'hello ';
print qx(perl foo2.pl);
qx is another way to run system commands like backticks. Thus perl foo2.pl is run with the output being sent back to your calling perl script.
So here the same using backticks. Also it uses a direct call to script (which is better):
print 'hello ';
print `./foo2.pl`;
And if you are expecting lots of output from the script then its best not to load it all into memory like above two examples. Instead use open like so:
print 'hello ';
open my $foo2, '-|', './foo2.pl';
print <$foo2>;
close $foo2;
And you can wrap this up into one print statement for "hello world" example:
print 'hello ', do {
open my $foo2, '-|', './foo2.pl';
<$foo2>;
};
/I3az/
Using a shell script (for example, a .bat file on Windows) to run various Perl scripts and combine their output is one way to solve the problem. However, I usually find that Perl itself provides a more powerful and flexible environment than shell scripts. To use Perl in this way, one place to start is by learning about the system and exec commands.
For example:
# In hello.pl
print "Hello\n";
# In world.pl
print "World\n";
# In hello_world.pl.
use strict;
use warnings;
system 'perl hello.pl > hello_world.txt';
system 'perl world.pl >> hello_world.txt';
You can use the following code also
file1.pl
use strict;
use warnings;
open (FH,">file") or die "$! can't open";
print FH "WELCOME\n";
file2.pl
use strict;
use warnings;
open (FH,">>file") or die "$! can't open";
print FH "WELCOME2\n";
The file content is
WELCOME
WELCOME2
If you know beforhand that the script you want to execute from inside the other script is also Perl, you should use do EXPR (https://perldoc.perl.org/functions/do.html).
This executes the contents of the file EXPR in the context of the running perl process and saves you from starting new cmd.exe and perl.exe instances.
hello.pl:
print "Hello";
do "world.pl";
wordl.pl:
print "World";