Best practices for passing C strings

12

Indeed, that works! Great trick.

Edit: in case someone wants to use this, here is the full version:
Edit 2: the default setting is supposed to be trim = .true..

function f_c_string(string,trim)
  use, intrinsic :: iso_c_binding, only: c_char,c_null_char
  implicit none
  character(len=*), intent(in) :: string
  logical, intent(in), optional :: trim

  character(kind=c_char,len=:), allocatable :: f_c_string
  logical :: trim_

  trim_ = .true.
  if (present(trim)) trim_ = trim

  block
    intrinsic trim
    if (trim_) then
      f_c_string = trim(string)//c_null_char
    else
      f_c_string = string//c_null_char
    end if
  end block
end function
2 Likes