Re: {} Questions

On 21.08.2024 13:48, Mike Sanders wrote:

 

[ Concerning the basic awk syntax:  condition { action }  ]

And yet there's still more implied nuance somehow. Let me try to articulate
my thoughts...
 
- These types of constructs are 'auto' ran per line of input (assuming
  its not located within another user-written function) that I get.

You cannot have these constructs with their given semantics inside a
function. You'd have to formulate them explicitly (in the imperative
form) with 'if', as in

  function f ()
  {
      if (condition) action
  }

  Perhaps a potential efficiency hit to be aware of.
 
- There's also the scope of variables to consider... Because any
  variable's located outside of a user-written function or conversely
  located within a 'bare naked' construct is global, or at least
  exposed to the entire script's 'world', so I want be careful here...

All variables have global scope, with the exception of those specified
in a function argument list along with the real arguments, as in

  function f (arg1, arg2,   local1, local2)  { global = arg1 ; ... }
  f ("Hello", 42);

(There's some caveat with arrays in the function argument list.)

Janis

 
  I'm guessing that any construct that lacks a function signature
  is globally scoped:
 
  { im_global = 42 }
 
  while those with a function signature (located within parentheses)
  are locally scoped:
 
  function private(private_var1) { private_var1 = "foo" }
 
- And 2 more...
 
  $ awk '{ v="im_global" }'
 
  $ awk -f foo -v global=55
 
  Anything within the above 2 are global as well?
 
Just thinking aloud here so, I'll let you long time posters describe
it more lucidly.