Linux Ask! is a Q & A web site specific for Linux related questions. Questions are collected, answered and audited by experienced Linux users.
Show HTTP response header using curl
Answer:
To show the response of HTTP request to a specific server, you can use the "curl -I" command.
Example:
# curl -I "http://www.example.com"
HTTP/1.0 302 Found
Location: http://www.iana.org/domains/example/
Server: BigIP
Connection: Keep-Alive
Content-Length: 0Allow a remote IP for incoming connection in UFW (Uncomplicated firewall)
Answer:
To allow a remote IP for incoming connection in Ubuntu's UFW (Uncomplicated firewall), you can use the following command:
# sudo ufw allow from x.x.x.x
Of course you need to reload the firewall.
# sudo ufw reload
Render web page using PyQt
Answer:
Qt bindings to WebKit have been added since 4.4, so you can use PyQt to script the browser (Webkit based).
Firstly, make sure you have installed the need packages:
# sudo apt-get install libqt4-core libqt4-webkit python-qt4
Then you can write a simple script to test, e.g.
#!/usr/bin/env python
import sys
from PyQt4.QtCore import *
from PyQt4.QtGui import *
from PyQt4.QtWebKit import *
app = QApplication(sys.argv)
web = QWebView()
web.load(QUrl("http://www.google.com"))
web.show()
sys.exit(app.exec_())
Create a short URL from command
Answer:
TinyUrl has a simple api for creating short URL for any web site.
E.g. Assume http://example.com
# curl 'http://tinyurl.com/api-create.php?url=http://example.com/'
http://tinyurl.com/kotu
Executing jobs in parallel using GNU parallel
Answer:
GNU parallel is a tool for executing jobs in parallel. It is not part of standard Linux distribution yet, so it is so worth to install it.
You can download the latest version from: http://ftp.gnu.org/gnu/parallel/
E.g.
# wget http://ftp.gnu.org/gnu/parallel/parallel-20101202.tar.bz2
# tar -jxvf parallel-20101202.tar.bz2
# cd parallel-20101202
# ./configure
# make && sudo make install
Example usages:
# echo -e "a\nb\nc" | parallel echo "foo"
foo a
foo b
foo c
