loadtxt: determine number of columns from first line to be read

src/stdlib_io.fypp

@@ -125,17 +125,18 @@ contains
 
  s = open(filename)
 
+ ! determine number or rows
+ nrow = number_of_rows(s)
+ skiprows_ = min(skiprows_, nrow)
+ if ( max_rows_ < 0 .or. max_rows_ > (nrow - skiprows_) ) max_rows_ = nrow - skiprows_
+
  ! determine number of columns
- ncol = number_of_columns(s)
+ ncol = 0
+ if ( skiprows_ < nrow ) ncol = number_of_columns(s, skiprows=skiprows_)
  #:if 'complex' in t1
  ncol = ncol / 2
  #:endif
 
- ! determine number or rows
- nrow = number_of_rows(s)
- skiprows_ = min(skiprows_, nrow)
- if ( max_rows_ < 0 .or. max_rows_ > (nrow - skiprows_)) max_rows_ = nrow - skiprows_
-
  allocate(d(max_rows_, ncol))
 
  do i = 1, skiprows_
@@ -196,17 +197,25 @@ contains
  #:endfor
 
 
- integer function number_of_columns(s)
+ integer function number_of_columns(s, skiprows)
  !! version: experimental
  !!
  !! determine number of columns
  integer,intent(in) :: s
+ integer, intent(in), optional :: skiprows
 
- integer :: ios
+ integer :: ios, skiprows_
  character :: c
  logical :: lastblank
 
+ skiprows_ = optval(skiprows, 0)
+
  rewind(s)
+
+ do i = 1, skiprows_
+ read(s, *)
+ end do
+
  number_of_columns = 0
  lastblank = .true.
  do