alert

alert conjures up the typical alert window with a pre-defined icon, explanatory text and up to three buttons. It will return the title of the pressed button and an exit status (starting with 0). For example, this is made of the line:

alert --idea "FantasticApp(tm) installed successfully!
Would you like a link to it?" "On Desktop" "In Deskbar" "No thanks"

filepanel

filepanel displays a load or save file panel and lets the user choose a file or location. As a return value you'll get the chosen file or folder's path. There are several parameters available, for example to set a starting directory, a window title, a default name when saving or restrictions to the allowed types of files. This is an example of

filepanel -s -t "Save your logfile" -d ~/config/settings -n Fantastic.log

waitfor

waitfor is a nice way to wait for a particular application or thread to be started or to have ended.

query

query is the commandline version of the Find panel. In fact, a quick way to generate the search term is to build a query in the Find panel, switch to by formula, add double quotes (") in front and back and paste the whole string after your query command in Terminal or your script.

checkfs

checkfs is an important tool to check for errors in your file system. Simply add the volume or device name and it'll run through every file and correct inconsistencies where possible.

desklink

desklink can install an icon for any file, folder, query or application in the Deskbar tray. It also offers the option to provide a context menu when right-clicking an icon to execute special actions. As an example, try this to add the commandline app screenshot with various options (the "\" in the first line is just for the line break in Terminal):

 desklink "cmd=Active window (2s):/bin/screenshot --window --border --delay 2" \
"cmd=Remove replicant:desklink --remove=screenshot" /bin/screenshot

diskimage

diskimage lets you register a regular file as disk device. For example, you can register a Haiku anyboot image, mount it in Tracker and copy, edit or remove files there before using it as source in the Installer.

open

open is a very handy little tool. With it you open any file with its preferred application, or start a specific application by its signature without the need to know its exact path. It also works with URLs and even with the "virtual" directories . for the current directory and .. for the parent, opening the folder in Tracker.