The control flow commands alter the order of execution of commands within a shell script. The Bourne Again and Z Shells share a common syntax, whereas the TC Shell uses a different syntax (page 714). Control structures include the if…then, for…in, while, until, and case statements. In addition, the break and continue statements work in conjunction with the control flow structures to alter the order of execution of commands within a script.
The syntax of the if…then control structure is
if test-command then commands fi
The bold words in the syntax description are the items you supply to cause the structure to have the ...