Fiddler - QuickExec Reference

Fiddler is one of the most common http debugging tool today.
Most of you know what is Fiddler and what can we do with him.

But for the rest, so….

What is Fiddler?

Fiddler is a HTTP Debugging Proxy which logs all HTTP traffic between your computer and the Internet. Fiddler allows you to inspect all HTTP Traffic, set breakpoints, and "fiddle" with incoming or outgoing data. Fiddler includes a powerful event-based scripting subsystem, and can be extended using any .NET language.

Fiddler is freeware and can debug traffic from virtually any application, including Internet Explorer, Mozilla Firefox, Opera, and thousands more.

QuickExec Reference

Fiddler's QuickExec box allows you to launch script-commands quickly.

Keyboard Hints

Hit ALT+Q to quickly set focus to the QuickExec box. If Fiddler isn't active, hit CTRL+ALT+F first to activate Fiddler.
In the QuickExec box, hit CTRL+I to insert the URL of the currently selected session in the session list.
There's a hotkey for virtually everything in Fiddler. See the Keyboard Reference.

Default commands

The QuickExec commands listed below are available in the latest available Beta version of Fiddler.

Command	Action	Sample usage
bold	Mark any future sessions in bold if the url contains the target string	bold /bar.aspx bold <-- Call with no parameter to clear
bpafter	Break any response where the RequestURI contains the specified string	bpafter /favicon.ico \| bpafter <-- Call with no parameter to clear
bps	Break any response where the status code matches	bps 404 bps <-- Call with no parameter to clear
bpv or bpm	Request Method breakpoint	bpv POST bpv <-- Call with no parameter to clear
bpu	bpu /myservice.asmx bpu <-- Call with no parameter to clear	bpu /myservice.asmx bpu <-- Call with no parameter to clear
cls or clear	clear the session list	cls
dump	dump all sessions to a zip archive in C:\	dump
g or go	Resume all breakpointed sessions	g
help	show this page	help
hide	Hide Fiddler in System tray	hide
urlreplace	Replace any string in URLs with a different string	urlreplace SeekStr ReplaceWithStr urlreplace <-- Call with no parameters to clear
start	Register as the system proxy	Register as the system proxy
stop	Unregister as the system proxy	stop
show	Restore Fiddler from system tray -- more useful when triggering rules from ExecAction.exe (see below)	show
select	Select any session where the response Content-Type header contains the specified string.	select image select css select htm
allbut or keeponly	Hide all sessions except those where Content-Type header contains the specified string.	select image select css select htm
quit		quit

Writing your own commands

You can easily add new commands by editing your FiddlerScript. Click Rules | Customize Rules. Scroll down to the OnExecAction function and simply add your own commands.
If you're developing a FiddlerExtension, you can implement the IHandleExecAction interface and handle the OnQuickExec event and respond accordingly.

Using ExecAction.exe

ExecAction.exe is a command line executable which is suitable for calling from batch files or unit tests. It passes its command line into FiddlerScript's OnExecAction function for processing, just like Fiddler's QuickExec box. The ExecAction commands can be handled by FiddlerScript or FiddlerExtensions.
ExecAction.exe is installed into the Fiddler directory inside your Program Files folder.

Usage:
ExecAction SCRIPTPARAMETER
ExecAction "PARAM1 PARAM2"

ExecAction sets %ERRORLEVEL% to