Ch.7 Seeing the World as the Shell Sees It Flashcards
What does echo do
Display a line of text
What is the mechanism by which wildcards work?
Pathname Expansion
What does Tilde Expansion do? What is the Tilde?
When used at the beginning of a word, it expands into the name of the home directory of the named user or, if no user is named, the home directory of the current user. ~
i.e.
echo ~
/home/pi
What form does Arithmetic expansion use?
$((expression))
Arithmetic expression only supports what?
Integers (Whole numbers, no decimals)
Arithmetic Expansion Description for Addiction
+
Arithmetic Expansion operation for subtraction
-
Arithmetic Expansion operation for multiplication
*
Arithmetic Expansion operation for division?
/
Arithmetic Expansion operation for remainder (modulo)
%
Arithemetic Expansion operation for Expnentiation
**
What expansion creates multiple text strings?
Brace Expansion {}
What may a brace expression contain in between {}?
Either a comma-separated list of strings 2. a range or intergers 3. single characters.
What is the leading portion of a pattern to be brace expanded?
preamble
What is the trailing portion of a pattern to be brace expanded?
postscript
