Embedded Linux Development using Yocto Projects - Second Edition

Appending and prepending

BitBake offers two sets of appending and prepending operators. The first are += and =+. The following code illustrates their use:

B = "bval"B += "additionaldata"C = "cval"C =+ "test"

At the end of this example, B contains bval additionaldata and C contains test cval. It is important to note that these operators include an extra space between each call.

When we wish to avoid adding spaces, we use the .= and =. operators. Look at the following code:

B = "bval"B .= "additionaldata"C = "cval"C =. "test"

In this example, B is now bvaladditionaldata and C is testcval. In contrast to the preceding example, the .= and =. operators add no additional space. Commonly, the += and =+ operators are used to add items to lists while ...