# call proc

Source: https://ref.dm-lang.org/proc/call

### Format
- `call(ProcRef)(Arguments)`
- `call(Object,ProcName)(Arguments)`
- `call(LibName,FuncName)(Arguments) (use `call_ext()` instead)`


### Args
- `ProcRef`: path of proc (/proc/MyProc)
- `Object`: source of proc or verb
- `ProcName`: name of proc or verb ("MyProc")
- `LibName`: name of external library ("test.DLL")
- `FuncName`: name of function in external library ("func")


### Returns
> The return value of the proc being called.

This instruction exists in order to call procs dynamically, since the proc reference or name may be an expression rather than a hard-coded value. This may serve the same purpose as a "function pointer" in C programs.

The following examples do not demonstrate why you would want to do this, but the syntax is illustrated. The first one calls a specific procedure by using a path reference to that procedure.

```dm /call/
/proc/MyProc(Arg)
   usr << "MyProc([Arg])"
mob
   var
      MyProc = /proc/MyProc
   verb
      call_myproc()
         call(MyProc)("Hello, world!")
```

The next example calls an object procedure (or verb) by name, rather than by path.

```dm /call/
mob
   proc
      Proc1(Arg)
         usr << "Proc1([Arg])"
      Proc2(Arg)
         usr << "Proc2([Arg])"
   verb
      call_proc(Proc in list("Proc1","Proc2"))
         call(src,Proc)("Hello, world!")
```

> [!note]
> 
> In prior versions, `call()` was also used to access third-party libraries (.DLL files on Windows, .SO files on Unix), but this has been moved to [call_ext()](https://ref.dm-lang.org/proc/call_ext.md) for clarity.

### See also
- [arglist proc](https://ref.dm-lang.org/proc/arglist.md)
- [call_ext proc](https://ref.dm-lang.org/proc/call_ext.md)
- [hascall proc](https://ref.dm-lang.org/proc/hascall.md)
- [path operators](https://ref.dm-lang.org/operator/path/index.md)