Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.
Simple port forwarding using SSH
Answer:
Assume you are working at office, you want to browse the example.com securely, you can do so by using a computer at home (e.g. HOME_IP)to build a secure tunnel using ssh.
# sudo ssh -L 80:example.com:80 HOME_IP
Then in your browser, type http://localhost and you can view the example.com securely.
Determine file type using the file command
Answer:
If you want to determine file type, you can try the file command:
# file /usr/share/perl5/Time/Zone.pm
/usr/share/perl5/Time/Zone.pm: Perl5 module source text
# file /usr/share/vim/vim72/doc/usr_90.txt
/usr/share/vim/vim72/doc/usr_90.txt: ASCII English text
How to find a Perl Module's Path
Answer:
For example, we want to know where the module JSON and related modules exist in the local file system, we can try:
# perl -MJSON -e'print $_ . " => " . $INC{$_} . "\n" for keys %INC'
attributes.pm => /usr/share/perl/5.10/attributes.pm
XSLoader.pm => /usr/local/lib/perl/5.10.0/XSLoader.pm
warnings/register.pm => /usr/share/perl/5.10/warnings/register.pm
Carp.pm => /usr/share/perl/5.10/Carp.pm
Exporter/Heavy.pm => /usr/share/perl/5.10/Exporter/Heavy.pm
common/sense.pm => /usr/local/share/perl/5.10.0/common/sense.pm
vars.pm => /usr/share/perl/5.10/vars.pm
Exporter.pm => /usr/share/perl/5.10/Exporter.pm
strict.pm => /usr/share/perl/5.10/strict.pm
constant.pm => /usr/local/share/perl/5.10.0/constant.pm
warnings.pm => /usr/share/perl/5.10/warnings.pm
JSON/XS.pm => /usr/local/lib/perl/5.10.0/JSON/XS.pm
overload.pm => /usr/share/perl/5.10/overload.pm
base.pm => /usr/share/perl/5.10/base.pm
JSON.pm => /usr/local/share/perl/5.10.0/JSON.pm
How to install GCC (C/C++) compiler in Ubuntu Linux
Answer:
It is easy to install standard GCC (C/C++) compiler in Ubuntu, just a single command:
# sudo apt-get install build-essential
Besides the core compiler, other useful build related tools will also be installed.
That's all.
Show the Domain Name Servers for a domain
Answer:
To show the Domain Name Servers for a domain, use the command below:
E.g. example.com
# nslookup -type=ns example.com
Server: 203.98.160.11
Address: 203.98.160.11#53
Non-authoritative answer:
example.com nameserver = b.iana-servers.net.
example.com nameserver = a.iana-servers.net.
Authoritative answers can be found from:
a.iana-servers.net internet address = 192.0.34.43
b.iana-servers.net internet address = 193.0.0.236
b.iana-servers.net has AAAA address 2001:610:240:2::c100:ec