Question

Why is the shift command an important tool in Linux/UNIX?                                                                                                                                                                                               13

Answer 1

Yup, shift command is an important tool in Linux/UNIX not only because of it's use it for shifting purpose such as right shift or left shift or due to it's ability to perform arithmatic operations through shift command but mainly due to it's ability to provide access to various elements such as elements in array and It can also be used to loop through arguments.Shift can be applied to while,untill,and even for loops for handling arrays in much more subtle ways than can a simple for loop.

Example:

• It lets you access the tenth argument (if there is one) more easily.  $10 doesn’t work – it’s interpreted as $1 concatenated with a 0 (and so might produce something like Hello0). After a shift, the tenth argument becomes $9. (However, in most modern shells, you can use ${10}.)
• set -f -- $args; IFS=$split; for arg do set -- $arg; shift "${number_of_fields_to_discard}" && fn_that_wants_split_arg "$arg";