Functions EXAMPLE 14.16 User-defined shell functions Users can define functions in bash that then work like built-in commands. Many users, for example, define 11 as a shortcut for ls-1, which lists files in the cur rent directory in "long format" function 11 O f ls -1 "0" 4.2 Problem Domains 71 Within the function, $1 represents the first parameter, $2 represents the second, and so on. In the definition of 11, $0 represents the entire parameter list. Func- tions can be arbitrarily complex. In particular, bash supports both local variables and recursion. Shells in the csh family provide a more primitive alias mecha nism that works via macro expansion Functions EXAMPLE 14.16 User-defined shell functions Users can define functions in bash that then work like built-in commands. Many users, for example, define 11 as a shortcut for ls-1, which lists files in the cur rent directory in "long format" function 11 O f ls -1 "0" 4.2 Problem Domains 71 Within the function, $1 represents the first parameter, $2 represents the second, and so on. In the definition of 11, $0 represents the entire parameter list. Func- tions can be arbitrarily complex. In particular, bash supports both local variables and recursion. Shells in the csh family provide a more primitive alias mecha nism that works via macro expansion