You can use the system call from the os module to execute an external program: >>> import os >>> os.system(the_command_line_st... However, the path to the executable contains a space character, the system call treats the strings after the first space as arguments, causing an error. Python doc recommends the use of the subprocess module: The subprocess module provides more powerful facilities for spawning new processes and retrieving their results; using that module is preferable to using this function. For example, using wget to get the google home page: >>> from subprocess import Popen, PIPE >>> (out... or >>> import subprocess >>> subprocess.call(['cur...

The C shell allows you to define aliases with arguments: \!^ passes the first argument, \!* passes all arguments. Examples from http://unixhelp.ed.ac.uk : alias print 'lpr \!^ -Pps5' alias print 'lp... In ksh or bash you cannot define alias with arguments. Use function instead.

In the simple taglib example , I used a tag handler class to implement a taglib. This is an example to implement a taglib with a UI component. The purpose is to use a custom tag to split a string and print each part in a separate paragraph, i.e., print <p>john</p> <p>steve</p> <p>mike</p> with custom tag <my:foreach> : <my:foreach var="who" value="john steve mike"> ... These are the files: pom.xml <project xmlns="http://maven.apache.org/POM/4.0.0"... src/main/java/com/example/UIForeash.java : package com.example; import java.io.IOExcep... src/main/resources/META-INF/faces-config.xml : <?xml version="1.0" encoding="UTF-8"?> <faces-c... src/main/resources/META-INF/foreach.taglib.xml : <?xml version="1.0" encoding="UTF-8"?> <facelet... How to use: Put the JAR file generated by the above project in the WEB-INF/lib folder of the web app. If the web app is a Maven project, just add the taglib project as a dependency:...

In the test for the simple taglib example , I used a literal string for the name attribute: <my:hello name="Jack"/> What happens if the name attribute contains EL expresson? For example: <my:hello name="#{param['name']}"/> If EL works, the tag should take the value of the " name " request parameter and print it out. But the tag as implemented in the simple taglib example prints the literal string: Hello #{param['name']}! I am FaceletTag. In order to make a tag to recognize EL, we have to use TagAttribute.getValue(FaceletContext ctx) instead of TagAttribute.getValue() . The latter returns the literal value of the attribute. The HelloTagHandler should be changed to: package com.example; import java.io.IOExcep... Rebuild the taglib and test with a URL like this: http://localhost:8080/facelet-test/?name=Jack The tag will print:...

Use tcpdump to monitor traffic on a network: To print all incoming and outgoing packets on host 192.168.0.1 : tcpdump host 192.168.0.1 To print all incoming and outgoing IP packets on host firebird : tcpdump ip host firebird To write raw packets to a file, rather than parsing and printing them out: tcpdump ip host firebird -w /tmp/firebird.pcap To listen on interface eth0 (without this, tcpdump listens on the lowest numbered, configured up interface except loopback): tcpdump -i eth0 ip Use switch -X for more verbose output: tcpdump -i eth0 ip -X host 192.168.0.1 Outgoing from 192.168.0.1 : tcpdump -i eth0 ip -X src host 192.168.0.1 Incoming to 192.168.0.1 : tcpdump -i eth0 ip -X dst host 192.168.0.1 More verbose output: tcpdump -i eth0 tcp -vvX host 192.168.0.1...

This is an Android app that dumps any binarized xml file as plain text - to the sdcard on the device or emulator. build.xml : <?xml version="1.0" encoding="UTF-8"?> <project... AndroidManifest.xml <?xml version="1.0" encoding="utf-8"?> <man... res/layout/main.xml <?xml version="1.0" encoding="utf-8"?> <Lin... res/values/strings.xml : <?xml version="1.0" encoding="utf-8"?> <res... src/com/android/xmltool/DumpXml.java package com.android.xmltool; import java.ut... Screenshot Pre-built APK can be downloaded from: http://code.google.com/p/android-binxml-dump/

Java's built-in classes are way too complex/flexible for a simple protocol like HTTP. This is a wrapper to simplify HTTP GET and POST. import java.io.*; import java.net.*; imp... A simple test: import java.io.*; import java.util.*; ...

grep is a versatile command with many variations (grep, egrep, fgrep, then various implementations). It uses a regula expression (regex) pattern to filter input. But then there are basic and extended flavors of regex - leading to even more confusion. And, beware that there are lots of bad examples of regex in the wild... There are two critical questions to ask when you use grep: which grep implementation are you using? what is the flavor of the regex? Here are some examples for gnu grep v2.7: # Find all numbers (no decimal point), basic regex... Use the -o flag to show only the matching part instead of the whole matching line: grep -o -E '\b[0-9]{2}\b' The good thing about the gnu grep is that it...

With JBoss (Tomcat?), the servlet container always appends the default charset ISO-8859-1 to the Content-Type header of a JSP response. For example, if you are using JSP to render PDF and put the following declaration at the top of the JSP: <%@ page contentType="application/pdf"%> These would be the headers in the HTTP response (notice that charset=ISO-8859-1 was appended to Content-Type ): HTTP/1.1 200 OK Server: Apache-Coyote/1.1 X-... And the output would be truncated a few bytes before non-ASCII characters were encountered, without any error messages ! Maybe you don't intend to output binary files with JSP, but still your response would be truncated without warning if the page happens to contain any non-ASCII characters (when the charset is the default charset=ISO-8859-1 ). However, if you...

I had a need to use Ajax to get a response from the server and conditionally render the results based on a status code. Additionally, I need to update multiple areas on the page from the results of one request. The code presented here uses jQuery and an XML response with CDATA sections to achieve that goal. Server side code (perl cgi): #!C:/perl/bin/perl.exe ## ## redirect ##... The HTML page: <html> <head> <script type="text/javascript...