The shift Statement
shift statement is used to process the positional parameters, one at a time, from left to right. As you'll remember, the positional parameters are identified as
$3, and so on. The effect of the
shift command is that each positional parameter is moved one position to the left and the current
$1 parameter is lost.
shift statement is useful when you are writing shell programs in which a user can pass various options. Depending on the specified option, the parameters that follow can mean different things or might not be there at all.
The format of the
shift command is as follows:
number is the number of places to be shifted and is optional. If not specified, the default is
1; that is, the parameters are shifted one position to the left. If specified, the parameters are shifted
number positions to the left.
- Special Statements: for, while, and Others
- The if Statement
- The case Statement
- The break and exit Statements
- if-else Statement
- 4.4.4 The Dispatcher
- About the author
- Chapter 7. The state machine
- Appendix E. Other resources and links
- Example NAT machine in theory
- The final stage of our NAT machine
- Compiling the user-land applications