notes

function_examples

<code>
, # Basic function
, print_something () {
, echo Hello I am a function
, }
, print_something
, print_something
, 
, # Basic function with parameters
, test_function_1 () {
, echo Hello I am a function $1
, }
, test_function_2 () {
, echo Hello I am function $1
, }
, test_function_1 1
, test_function_2 two
, 
, Return Values
, Most other programming languages have the concept of a return value for functions,
, a means for the function to send data back to the original calling location.
, Bash functions dont allow us to do this. They do however allow us to set a return
, status. Similar to how a program or command exits with an exit status which
, indicates whether it succeeded or not. We use the keyword return to indicate
, a return status.
, 
, # Setting a return status for a function
, print_something () {
, echo Hello $1
, return 5
, }
, print_something World
, echo The previous function has a return value of $?
, 
, # Setting a return value to a function
, lines_in_file () {
, cat $1 | wc -l
, }
, num_lines=$( lines_in_file $1 )
, echo The file $1 has $num_lines lines in it.
, 
, # Setting a return value to a function
, lines_in_file () {
, cat $1 | wc -l
, }
, num_lines=$( lines_in_file $1 )
, echo The file $1 has $num_lines lines in it.
, 
, # Create a wrapper around the command ls
, ls () {
, command ls -lh
, }
, ls
, </code>
,