Revision [1354]
This is an old revision of SyntaxFunction made by DavidLee on 2010-05-02 09:15:58.
Functions
Functions can be declared in two forms, with or without the keyword "function". These are the equivalent to the forms for ksh.
In both forms the arguments to the functions are passed as positional parameters ($1 .. $N)
name () { list; }
This declares a function "name". The body of the function when executed runs in the same context as the parent shell, with the exception of Positional Parameters ($1 ... $N).
This means that variables assigned within the function have a "side effect" of writing into the global environment for the current shell.
Example
setit ()
{
A=$1 ;
}
A="no value"
echo $A
setit value
echo $AResult
no value value
function name () { list; }
This declares a function "name". The body of the function when executed runs in the a child shell context. Arguments are passed as positional parameters ($1 .. $N)
This means that variables assigned within the function *do not* have a "side effect" of writing into the global environment for the current shell.
Example
function setit ()
{
A=$1 ;
}
A="no value"
echo $A
setit value
echo $AResult
no value no value
Return Value
The Return value of a function is the return value of the last command, or the argument of the return function.
Example
foo ()
{
true ;
}
foo && echo Is TrueResult
Is True
Example
foo ()
{
return 2 ;
}
foo
echo $?Result
2
CoreSyntax
Commands
