[Chapter 45] 45.15 How to Unset all Command-Line Parameters
Author: Jerry Peek, Tim O'Reilly & Mike Loukides
Date: 1998-08-04T21:54:38Z

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| Chapter 45 Shell Programming for the Initiated |

## 45.15 How to Unset all Command-Line Parameters

The shift (44.17) command "shifts away" one command-line parameter. You can shift three times if there are three command-line parameters. Many shells also can take an argument, like shift 3, that tells how many times to shift; on those shells, you can `shift $# (44.15)`to unset all parameters.

The portable way to unset all command-line parameters is probably to set (44.19) a single dummy parameter, then shift it away:

>     set x
>     shift

Setting the single parameter wipes out whatever other parameters were set before.

- JP

45.14 Finding the Last Command-Line Argument |  | 45.16 Standard Input to a for Loop