added plt io prototype

CMakeLists.txt

+cmake_minimum_required(VERSION 3.15)
+project(scm_io)
+
+set(CMAKE_CXX_STANDARD 14)
+
+include_directories(src)
+
+enable_language(Fortran)
+set(dialect " -free -fimplicit-none ")
+set(bounds "-free -fimplicit-none ")
+set(CMAKE_Fortran_FLAGS_DEBUG "${CMAKE_Fortran_FLAGS_DEBUG} ${bounds} -g -fbacktrace -O0 -fcheck=all")
+set(CMAKE_Fortran_FLAGS "${CMAKE_Fortran_FLAGS} ${dialect}")
+
+set(plt_io
+        src/scm_io_plt.f90
+        src/test_io_plt.f90)
+
+add_executable(test_plt ${plt_io})

src/scm_io_plt.f90

+! Created by Andrey Debolskiy on 21.05.2024.
+
+module scm_io_plt
+    implicit none
+    !type declaration
+    type io_struct
+        character(len = 160) :: fname
+        integer :: status ! 0 - closed, 1 - opened
+        integer :: unit_id
+    end type io_struct
+
+    character(len = 160) tmp_str
+    integer, public :: nunits_max
+    public
+
+contains
+    subroutine set_file( f, fname )
+        implicit none
+        type(io_struct), intent(inout):: f
+        character(*), intent(in):: fname
+
+        if (f%status == 0) then
+            f%unit_id = get_file_unit()
+            open(f%unit_id, FILE=trim(fname))
+            f%status = 1
+            f%fname = trim(fname)
+        end if
+    end subroutine set_file
+
+    subroutine write_series(stamp, vals, nlength, f)
+        implicit none
+        type(io_struct), intent(inout):: f
+        integer, intent(in):: nlength
+        real, intent(in), dimension(nlength)::vals
+        real, intent(in):: stamp
+
+        write(f%unit_id,*) stamp, vals(:)
+    end subroutine write_series
+
+    subroutine write_profile(profs, nprof, z, nz, f)
+        implicit none
+
+        type(io_struct), intent(inout):: f
+        integer, intent(in):: nprof, nz
+        real, intent(in), dimension(nz, nprof)::  profs
+        real, intent(in), dimension(nz)::  z
+        integer k, n
+
+        if (f%status==1) then
+            do k = 1,nz
+                write(f%unit_id,*) z(k), profs(k,:)
+            end do
+            else
+                write(*,*) "Error in writing file:"
+                write(*,*) "                  ", f%fname
+                stop
+        end if
+    end subroutine write_profile
+
+    subroutine close_file(f)
+        implicit none
+        type(io_struct), intent(inout):: f
+
+        close(f%unit_id)
+        f%status = 0
+    end subroutine close_file
+
+    !   get_file_unit returns a unit number that is not in use
+    integer function get_file_unit ()
+        integer lu, iostat
+        integer, save:: m
+        logical, save:: initialized = .true.
+        logical   opened
+
+        if (initialized) then
+            m = nunits_max
+            initialized = .false.
+        end if
+
+        if (m < 8 ) then
+            m = 2 * nunits_max
+        end if
+
+        do lu = m,7,-1
+            inquire (unit=lu, opened=opened, iostat=iostat)
+            if (iostat.ne.0) cycle
+            if (.not.opened) exit
+        end do
+        !
+        get_file_unit = lu
+        return
+    end function get_file_unit
+
+end module scm_io_plt
\ No newline at end of file

src/test_io_plt.f90

+! Created by Andrey Debolskiy on 21.05.2024.
+
+program test_io_plt
+    use scm_io_plt
+    implicit none
+    integer, parameter :: nvar=5, nlength=10
+
+    !io variables
+    real, dimension (nvar):: series_val
+    type (io_struct) :: series_f
+
+    !local vars
+    integer nt, n
+    real t
+
+    !set output filenames
+    series_f%fname = 'test_io.plt'
+    call set_file(series_f, series_f%fname)
+
+    do nt=1,nlength
+    t = nt/100.0
+    do n=1,nvar
+        series_val(n)= 0.1 * n
+    end do
+        call write_series(t, series_val, nvar, series_f)
+    end do
+    call close_file(series_f)
+
+end program test_io_plt
\ No newline at end of file