# Tips and Tricks

ImageJ is easy to use, but sometimes you wish for some function that is actually implemented, yet you do not know how to trigger. This page lists a few of those tricks.

## Show the memory consumption

Just click on the status bar, and you will see how much memory is used, and how much memory is available.

## Execute external programs

The macro language allows executing programs, and capturing their output:

output = exec("dir /w");

## Quickly see return values

You do not need to wrap macro calls into write() calls: if you just write something like

getDirectory("plugins");

the return value will appear in your Log window when called.

## Find out in which menu (or .jar file) a certain command is

Hit Ctrl\|L to start the Command Finder. Type (part of) the name of the entry, then click on Show full information.

If Edit › Options › Misc… >Require command key for shortcuts is unchecked, typing L is sufficient.

## Put the main window to the foreground

Pressing the Return key on any image will bring the main window to the foreground.

## Close all images (without being asked whether to save them)

Plugins › Utilities › Close All Without Saving

## Set the foreground color

Double-click on the pipette, or hit Ctrl\|Shift\|K (on Macs, it is Cmd\|Shift\|K ), or select the menu item ‘‘Image › Color › Color Picker…

## Set the line width

Line selections can have a width larger than one, which also has an effect on line profiles. You can set it by double clicking on the line selection tool, or by calling Edit › Options › Line Width…

## Quickly copy a ROI from one image to another

Simply activate the image with the desired ROI, then the image you want to put that ROI into, and hit Ctrl\|Shift\|E . This triggers the Edit › Selection › Restore Selection which “restores” the selection.