! !MODULE: shr_file_mod.F90 --- Module to handle various file utilily functions.
!
! !DESCRIPTION:
!
! Miscilaneous methods to handle file and directory utilities as well as FORTRAN
! unit control. Also put/get local files into/from archival location
!
! File utilites used with CCSM Message passing:
!
! shr_file_stdio is the main example here, it changes the working directory,
!                changes stdin and stdout to a given filename.
!
! This is needed because some implementations of MPI with MPMD so that
! each executable can run in a different working directory and redirect
! output to different files.
!
! File name archival convention, eg.
!    call shr_file_put(rcode,"foo","mss:/USER/foo",rtpd=3650)
! is extensible -- the existence of the option file name prefix, eg. "mss:",
! and optional arguments, eg. rtpd-3650 can be used to access site-specific
! storage devices.  Based on CCM (atmosphere) getfile & putfile routines, but
! intended to be a more extensible, shared code.
!
! !REVISION HISTORY:
!   2006-05-08 E. Kluzek, Add in shr_file_mod and getUnit, freeUnif methods.
!   2000-??-?? B. Kauffman, original version circa 2000
!
! !INTERFACE: ------------------------------------------------------------------

MODULE shr_file_mod

  ! !USES:

  use shr_kind_mod  ! defines kinds
  use shr_sys_mod   ! system calls
  use shr_log_mod, only: s_loglev  => shr_log_Level
  use shr_log_mod, only: s_logunit => shr_log_Unit

  IMPLICIT none

  PRIVATE           ! By default everything is private to this module

  ! !PUBLIC TYPES:

  ! no public types

  ! !PUBLIC MEMBER FUNCTIONS:

  public :: shr_file_put          ! Put a file to an archive location
  public :: shr_file_get          ! Get a file from an archive location
  public :: shr_file_queryPrefix  ! Get prefix type for a filename
  public :: shr_file_getUnit      ! Get a logical unit for reading or writing
  public :: shr_file_freeUnit     ! Free a logical unit
  public :: shr_file_stdio        ! change dir and stdin and stdout
  public :: shr_file_chDir        ! change current working directory
  public :: shr_file_dirio        ! change stdin and stdout
  public :: shr_file_chStdIn      ! change stdin  (attach to a file)
  public :: shr_file_chStdOut     ! change stdout (attach to a file)
  public :: shr_file_setIO        ! open a log file from namelist
  public :: shr_file_setLogUnit   ! Reset the log unit number
  public :: shr_file_setLogLevel  ! Reset the logging debug level
  public :: shr_file_getLogUnit   ! Get the log unit number
  public :: shr_file_getLogLevel  ! Get the logging debug level

  ! !PUBLIC DATA MEMBERS:

  ! Integer flags for recognized prefixes on file get/put operations
  integer(SHR_KIND_IN), parameter, public :: shr_file_noPrefix      = 0 ! no recognized prefix
  integer(SHR_KIND_IN), parameter, public :: shr_file_nullPrefix    = 1 ! null:
  integer(SHR_KIND_IN), parameter, public :: shr_file_cpPrefix      = 2 ! cp:
  integer(SHR_KIND_IN), parameter, public :: shr_file_mssPrefix     = 3 ! mss:
  integer(SHR_KIND_IN), parameter, public :: shr_file_hpssPrefix    = 4 ! hpss:

  !EOP
  !--- unit numbers, users can ask for unit numbers from 0 to min, but getUnit
  !--- won't give a unit below min, users cannot ask for unit number above max
  !--- for backward compatability.
  !--- eventually, recommend min as hard lower limit (tcraig, 9/2007)
  integer(SHR_KIND_IN),parameter :: shr_file_minUnit = 10      ! Min unit number to give
  integer(SHR_KIND_IN),parameter :: shr_file_maxUnit = 99      ! Max unit number to give
  logical, save :: UnitTag(0:shr_file_maxUnit) = .false. ! Logical units in use

  !===============================================================================
CONTAINS
  !===============================================================================

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_put -- Put a file to an archival location.
  !
  ! !DESCRIPTION:
  !    a generic, extensible put-local-file-into-archive routine
  ! USAGE:
  !    call shr_file_put(rcode,"foo","/home/user/foo")
  !    if ( rcode /= 0 ) call shr_sys_abort( "error copying foo" )
  !    call shr_file_put(rcode,"foo","cp:/home/user/foo",remove=.true.)
  !    if ( rcode /= 0 ) call shr_sys_abort( "error copying foo" )
  !    call shr_file_put(rcode,"foo","mss:/USER/foo",rtpd=3650)
  !    if ( rcode /= 0 ) call shr_sys_abort( "error archiving foo to MSS" )
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_put(rcode,loc_fn,rem_fn,passwd,rtpd,async,remove)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    integer(SHR_KIND_IN),intent(out)         :: rcode  ! return code (non-zero -- error)
    character(*),        intent(in)          :: loc_fn ! local filename
    character(*),        intent(in)          :: rem_fn ! remote filename
    character(*),        intent(in),optional :: passwd ! password
    integer(SHR_KIND_IN),intent(in),optional :: rtpd   ! MSS retention period
    logical,             intent(in),optional :: async  ! true <=> asynchronous put
    logical,             intent(in),optional :: remove ! true <=> rm after put

    !EOP

    !----- local -----
    integer(SHR_KIND_IN)   :: rtpd2    ! MSS retention period
    logical                :: remove2  ! true <=> rm after put
    logical                :: async2   ! true <=> asynchronous put
    character(SHR_KIND_CL) :: passwd2  ! password
    character(SHR_KIND_CL) :: rfn      ! rem_fn without the destination prefix
    character(SHR_KIND_CL) :: cmd      ! command sent to system call
    integer(SHR_KIND_IN)   :: prefix   ! remote file prefix type

    !----- formats -----
    character(*),parameter :: subName = '(shr_file_put) '
    character(*),parameter :: F00 =   "('(shr_file_put) ',4a)"
    character(*),parameter :: F01 =   "('(shr_file_put) ',a,i3,2a)"
    character(*),parameter :: F02 =   "(a,i4)"

    !-------------------------------------------------------------------------------
    ! Notes:
    ! - On some machines the system call will not return a valid error code
    ! - when things are sent asynchronously, there probably won't be a error code
    !   returned.
    !-------------------------------------------------------------------------------

    remove2 =.false. ; if ( PRESENT(remove )) remove2 = remove
    async2  =.true.  ; if ( PRESENT(async  )) async2  = async
    passwd2 = " "    ; if ( PRESENT(passwd )) passwd2 = passwd
    rtpd2   = 365    ; if ( PRESENT(rtpd   )) rtpd2   = rtpd
    rcode   = 0
    prefix = shr_file_queryPrefix( rem_fn )

    if ( trim(rem_fn) == trim(loc_fn) ) then
       !------------------------------------------------------
       ! (remote file name) == (local file name) => do nothing
       !------------------------------------------------------
       cmd = 'do nothing: remote file = local file = '//trim(loc_fn)
       rcode = 0
    else if ( prefix == shr_file_cpPrefix .or. prefix == shr_file_noPrefix )then
       !------------------------------------------------------
       ! put via unix cp
       !------------------------------------------------------
       rfn = rem_fn
       if ( rem_fn(1:3) == "cp:") rfn = rem_fn(4:len_trim(rem_fn))
       cmd = '/bin/cp -f '//trim(loc_fn)//' '//trim(rfn)
       if (remove2) cmd = trim(cmd)//' && /bin/rm -f '//trim(loc_fn)
       if (async2 ) cmd = trim(cmd)//' & '
       call shr_sys_system(trim(cmd),rcode)
    else if ( prefix == shr_file_mssPrefix )then
       !------------------------------------------------------
       ! put onto NCAR's MSS
       !------------------------------------------------------
       if (rtpd2 > 9999) rtpd2 = 9999
       write(cmd,F02) '/usr/local/bin/msrcp -period ',rtpd2
       if (async2 .and. (.not. remove2) ) cmd = trim(cmd)//' -async '
       if (len_trim(passwd2) > 0 ) cmd = trim(cmd)//' -wpwd '//trim(passwd)
       cmd = trim(cmd)//' '//trim(loc_fn)//' '//trim(rem_fn)
       if (remove2) cmd = trim(cmd)//' && /bin/rm -f '//trim(loc_fn)
       if (async2 .and. remove2 ) cmd = trim(cmd)//' & '
       call shr_sys_system(trim(cmd),rcode)
    else if ( prefix == shr_file_hpssPrefix )then
       !------------------------------------------------------
       ! put onto LANL's hpss
       !------------------------------------------------------
       rcode = -1
       cmd = 'rem_fn='//trim(rem_fn)//' loc_fn='//trim(loc_fn)
       write(s_logunit,F00) 'ERROR: hpss option not yet implemented'
       call shr_sys_abort( subName//'ERROR: hpss option not yet implemented' )
    else if ( prefix == shr_file_nullPrefix )then
       ! do nothing
       cmd = "null prefix => no file archival, do nothing"
       rcode = 0
    end if

    if (s_loglev > 0) write(s_logunit,F01) 'rcode =',rcode,' cmd = ', trim(cmd)

  END SUBROUTINE shr_file_put

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_get -- Get a file from archival location.
  !
  ! !DESCRIPTION:
  !    a generic, extensible get-local-file-from-archive routine
  !
  ! USAGE:
  !    call shr_file_get(rcode,"foo","/home/user/foo")
  !    if ( rcode /= 0 ) call shr_sys_abort( "error getting file foo" )
  !    call shr_file_get(rcode,"foo","cp:/home/user/foo",remove=.true.)
  !    if ( rcode /= 0 ) call shr_sys_abort( "error getting file foo" )
  !    call shr_file_get(rcode,"foo","mss:/USER/foo",clobber=.true.)
  !    if ( rcode /= 0 ) call shr_sys_abort( "error getting file foo from MSS" )
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_get(rcode,loc_fn,rem_fn,passwd,async,clobber)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    integer(SHR_KIND_IN),intent(out)         :: rcode   ! return code (non-zero means error)
    character(*)        ,intent(in)          :: loc_fn  ! local filename
    character(*)        ,intent(in)          :: rem_fn  ! remote filename
    character(*)        ,intent(in),optional :: passwd  ! password
    logical             ,intent(in),optional :: async   ! true <=> asynchronous get
    logical             ,intent(in),optional :: clobber ! true <=> clobber existing file

    !EOP

    !----- local -----
    logical                :: async2   ! true <=> asynchronous get
    logical                :: clobber2 ! true <=> clobber existing file
    logical                :: exists   ! true <=> local file a ready exists
    character(SHR_KIND_CL) :: passwd2  ! password
    character(SHR_KIND_CL) :: rfn      ! rem_fn without the destination prefix
    character(SHR_KIND_CL) :: cmd      ! command sent to system call
    integer(SHR_KIND_IN)   :: prefix   ! remote file prefix type

    !----- formats -----
    character(*),parameter :: subName = '(shr_file_get) '
    character(*),parameter :: F00 =   "('(shr_file_get) ',4a)"
    character(*),parameter :: F01 =   "('(shr_file_get) ',a,i3,2a)"

    !-------------------------------------------------------------------------------
    ! Notes:
    ! - On some machines the system call will not return a valid error code
    ! - When things are sent asynchronously, there probably won't be a error code
    !   returned.
    !-------------------------------------------------------------------------------

    passwd2  = " "     ; if (PRESENT(passwd )) passwd2  = passwd
    async2   = .false. ; if (PRESENT(async  )) async2   = async
    clobber2 = .false. ; if (PRESENT(clobber)) clobber2 = clobber
    rcode    = 0

    inquire(file=trim(loc_fn),exist=exists)
    prefix = shr_file_queryPrefix( rem_fn )

    if ( exists .and. .not. clobber2 ) then
       !------------------------------------------------------
       ! (file exists) and (don't clobber) => do nothing
       !------------------------------------------------------
       cmd = 'do nothing: file exists & no-clobber for '//trim(loc_fn)
       rcode = 0
    else if ( trim(rem_fn) == trim(loc_fn) ) then
       !------------------------------------------------------
       ! (remote file name) == (local file name) => do nothing
       !------------------------------------------------------
       cmd = 'do nothing: remote file = local file for '//trim(loc_fn)
       rcode = 0
    else if ( prefix == shr_file_cpPrefix .or. prefix == shr_file_noPrefix )then
       !------------------------------------------------------
       ! get via unix cp
       !------------------------------------------------------
       rfn = rem_fn  ! remove prefix from this temp file name
       if (rem_fn(1:3) == "cp:") rfn = rem_fn(4:len_trim(rem_fn))
       cmd = '/bin/cp -f '//trim(rfn)//' '//trim(loc_fn)
       if (async2) cmd = trim(cmd)//' & '
       call shr_sys_system(trim(cmd),rcode)
    else if ( prefix == shr_file_mssPrefix )then
       !------------------------------------------------------
       ! get from NCAR's MSS
       !------------------------------------------------------
       cmd = '/usr/local/bin/msrcp '
       if (async2)   cmd = trim(cmd)//' -async '
       cmd = trim(cmd)//' '//trim(rem_fn)//' '//trim(loc_fn)
       call shr_sys_system(trim(cmd),rcode)
    else if ( prefix == shr_file_hpssPrefix )then
       !------------------------------------------------------
       ! get from LANL's hpss
       !------------------------------------------------------
       rcode = -1
       cmd = 'rem_fn='//trim(rem_fn)//' loc_fn='//trim(loc_fn)
       write(s_logunit,F00) 'ERROR: hpss option not yet implemented'
       call shr_sys_abort( subName//'ERROR: hpss option not yet implemented' )
    else if ( prefix == shr_file_nullPrefix )then
       ! do nothing
       cmd = "null prefix => no file retrieval, do nothing"
       rcode = 0
    end if

    if (s_loglev > 0) write(s_logunit,F01) 'rcode =',rcode,' cmd = ', trim(cmd)

  END SUBROUTINE shr_file_get

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_queryPrefix -- Get the prefix type from a filepath.
  !
  ! !DESCRIPTION:
  !
  ! !INTERFACE: ------------------------------------------------------------------

  integer(SHR_KIND_IN) FUNCTION shr_file_queryPrefix( filepath, prefix )

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    character(*), intent(in)            :: filepath ! Input filepath
    character(*), intent(out), optional :: prefix   ! Output prefix description

    !EOP

    !----- local -----

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    if (     filepath(1:5) == "null:" )then
       shr_file_queryPrefix = shr_file_nullPrefix
       if ( present(prefix) ) prefix = "null:"
    else if( filepath(1:3) == "cp:" )then
       shr_file_queryPrefix = shr_file_cpPrefix
       if ( present(prefix) ) prefix = "cp:"
    else if( filepath(1:4) == "mss:" )then
       shr_file_queryPrefix = shr_file_mssPrefix
       if ( present(prefix) ) prefix = "mss:"
    else if( filepath(1:5) == "hpss:" )then
       shr_file_queryPrefix = shr_file_hpssPrefix
       if ( present(prefix) ) prefix = "hpss:"
    else
       shr_file_queryPrefix = shr_file_noPrefix
       if ( present(prefix) ) prefix = ""
    end if

  END FUNCTION shr_file_queryPrefix

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_getUnit -- Get a free FORTRAN unit number
  !
  ! !DESCRIPTION: Get the next free FORTRAN unit number.
  !
  ! !REVISION HISTORY:
  !     2005-Dec-14 - E. Kluzek - creation
  !
  ! !INTERFACE: ------------------------------------------------------------------

  INTEGER FUNCTION shr_file_getUnit ( unit )

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    integer(SHR_KIND_IN),intent(in),optional :: unit ! desired unit number

    !EOP

    !----- local -----
    integer(SHR_KIND_IN)   :: n      ! loop index
    logical                :: opened ! If unit opened or not

    !----- formats -----
    character(*),parameter :: subName = '(shr_file_getUnit) '
    character(*),parameter :: F00   = "('(shr_file_getUnit) ',A,I4,A)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------
    shr_file_getUnit = -1
    if (present (unit)) then
       inquire( unit, opened=opened )
       if (unit < 0 .or. unit > shr_file_maxUnit) then
          write(s_logunit,F00) 'invalid unit number request:', unit
          call shr_sys_abort( 'ERROR: bad input unit number' )
       else if (opened .or. UnitTag(unit) .or. unit == 0 .or. unit == 5 &
            .or. unit == 6) then
          write(s_logunit,F00) 'unit number ', unit, ' is already in use'
          call shr_sys_abort( 'ERROR: Input unit number already in use' )
       else
          shr_file_getUnit = unit
          UnitTag (unit)   = .true.
          return
       end if

    else
       ! --- Choose first available unit other than 0, 5, or 6  ------
       do n=shr_file_maxUnit, shr_file_minUnit, -1
          inquire( n, opened=opened )
          if (n == 5 .or. n == 6 .or. opened) then
             cycle
          end if
          if ( .not. UnitTag(n) ) then
             shr_file_getUnit = n
             UnitTag(n)       = .true.
             return
          end if
       end do
    end if

    call shr_sys_abort( subName//': Error: no available units found' )

  END FUNCTION shr_file_getUnit

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_freeUnit -- Free up a FORTRAN unit number
  !
  ! !DESCRIPTION: Free up the given unit number
  !
  ! !REVISION HISTORY:
  !     2005-Dec-14 - E. Kluzek - creation
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_freeUnit ( unit)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    integer(SHR_KIND_IN),intent(in) :: unit  ! unit number to be freed

    !EOP

    !----- local -----

    !----- formats -----
    character(*), parameter :: subName = '(shr_file_freeUnit) '
    character(*), parameter :: F00 =   "('(shr_file_freeUnit) ',A,I4,A)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    if (unit < 0 .or. unit > shr_file_maxUnit) then
       if (s_loglev > 0) write(s_logunit,F00) 'invalid unit number request:', unit
    else if (unit == 0 .or. unit == 5 .or. unit == 6) then
       call shr_sys_abort( subName//': Error: units 0, 5, and 6 must not be freed' )
    else if (UnitTag(unit)) then
       UnitTag (unit) = .false.
    else
       if (s_loglev > 0) write(s_logunit,F00) 'unit ', unit, ' was not in use'
    end if

    return

  END SUBROUTINE shr_file_freeUnit

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_stdio -- Change working directory, and redirect stdin/stdout
  !
  ! !DESCRIPTION:
  !   1) change the cwd (current working directory) and
  !   2) redirect stdin & stdout (units 5 & 6) to named files,
  !   where the desired cwd & files are specified by namelist file.
  !
  !   Normally this is done to work around limitations in the execution syntax
  !   of common MPI implementations.  For example, SGI's mpirun syntax is not
  !   flexible enough to allow MPMD models to select different execution
  !   directories or to redirect stdin & stdout on the command line.
  !   Such functionality is highly desireable for CCSM purposes.
  !   ie. mpirun can't handle this:
  !   unix> cd /usr/tmp/jdoe/csm/case01/atm ; atm < atm.parm > atm.log &
  !   unix> cd /usr/tmp/jdoe/csm/case01/cpl ; cpl < cpl.parm > cpl.log &
  !   etc.
  !
  ! ASSUMPTIONS:
  ! o if the cwd, stdin, or stdout are to be changed, there must be a namelist
  !   file in the cwd named <model>_stdio.nml  where <model> is provided via
  !   subroutine dummy argument.
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_stdio(model)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    character(*),intent(in) :: model ! used to construct env varible name

    !EOP

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_stdio) '
    character(*),parameter :: F00   = "('(shr_file_stdio) ',4a)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    call shr_file_chdir   (model) ! changes cwd
    call shr_file_chStdOut(model) ! open units 5 & 6 to named files
    call shr_file_chStdIn (model) ! open units 5 & 6 to named files

  END SUBROUTINE shr_file_stdio

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_chdir -- Change working directory.
  !
  ! !DESCRIPTION:
  !   change the cwd (current working directory), see shr_file_stdio for notes
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_chdir(model, rcodeOut)

    ! !USES:

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    character(*)        ,intent(in)           :: model    ! used to construct env varible name
    integer(SHR_KIND_IN),intent(out),optional :: rcodeOut ! Return error code

    !EOP

    !--- local ---
    character(SHR_KIND_CL) :: dir      ! directory to cd to
    integer  (SHR_KIND_IN) :: rcode    ! Return error code
    character(SHR_KIND_CL) :: filename ! namelist file to read

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_chdir) '
    character(*),parameter :: F00 =   "('(shr_file_chdir) ',4a)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    call shr_file_stdioReadNL( model, filename, dirOut=dir, rcodeOut=rcode )
    if (dir /= "nochange") then
       call shr_sys_chdir(dir ,rcode)
       if (s_loglev > 0) write(s_logunit,F00) "read ",trim(filename),", changed cwd to ",trim(dir)
    else
       if (s_loglev > 0) write(s_logunit,F00) "read ",trim(filename),", cwd has *not* been changed"
       rcode = 1
    endif
    if ( present(rcodeOut) ) rcodeOut = rcode

  END SUBROUTINE shr_file_chdir

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_dirio --- Change stdin and stdout.
  !
  ! !DESCRIPTION:
  !   change the stdin & stdout (units 5 & 6), see shr_file_stdio for notes
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_dirio(model)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    character(*),intent(in) :: model ! used to construct env varible name

    !EOP

    !--- local ---

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_dirio) '

    !-------------------------------------------------------------------------------
    ! Notes:
    !
    !-------------------------------------------------------------------------------

    call shr_file_chStdIn (model)
    call shr_file_chStdOut(model)

  END SUBROUTINE shr_file_dirio

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_chStdIn -- Change stdin
  !
  ! !DESCRIPTION:
  !   change the stdin (unit 5), see shr_file_stdio for notes
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_chStdIn( model, NLFilename, rcodeOut )

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    character(*)          ,intent(in)           :: model      ! used to construct env var name
    character(SHR_KIND_CL),intent(out),optional :: NLFilename ! open unit 5 to this
    integer  (SHR_KIND_IN),intent(out),optional :: rcodeOut   ! return code

    !EOP

    !--- local ---
    character(SHR_KIND_CL) :: stdin    ! open unit 5 to this file
    character(SHR_KIND_CL) :: nlfile   ! Namelist filename for model to read from
    character(SHR_KIND_CL) :: filename ! namelist file to read
    integer  (SHR_KIND_IN) :: rcode    ! return code

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_chStdIn) '
    character(*),parameter :: F00   = "('(shr_file_chStdIn) ',4a)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    call shr_file_stdioReadNL( model, filename, stdinOut=stdin, &
         nlfileOut=nlfile, rcodeOut=rcode )
    if (stdin  /= "nochange") then
       open(unit=5,file=stdin ,status='UNKNOWN',iostat=rcode)
       if ( rcode /= 0 )then
          if (s_loglev > 0) &
               write(s_logunit,F00) "read ",trim(filename),': error opening file as unit 5:', &
               trim(nlfile)
       else
          if (s_loglev > 0) &
               write(s_logunit,F00) "read ",trim(filename),': unit 5 connected to ', &
               trim(stdin)
       end if
    else
       if (s_loglev > 0) write(s_logunit,F00) "read ",trim(filename), &
            ': unit 5 has *not* been redirected'
    endif
    if ( len_trim(nlfile) > 0) then
       if (s_loglev > 0) write(s_logunit,F00) "read ",trim(filename), &
            ': read namelist from file:',trim(nlfile)
       if ( .not. present(NLFilename) )then
          if (s_loglev > 0) write(s_logunit,F00) "error: namelist filename NOT present"
          rcode = 7
       end if
    else
       if (s_loglev > 0) write(s_logunit,F00) "read ",trim(filename),", "
       if ( present(NLFilename) )then
          if (s_loglev > 0) write(s_logunit,F00) "error: namelist filename present, but null"
          rcode = 8
       end if
    endif
    if ( present(NLFilename) ) NLFilename = nlfile
    if ( present(rcodeOut)   ) rcodeOut   = rcode

  END SUBROUTINE shr_file_chStdIn

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_stdout -- Change stdout
  !
  ! !DESCRIPTION:
  !   change the stdout (unit 6), see shr_file_stdio for notes
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_chStdOut(model,rcodeOut)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:
    !--- arguments ---
    character(*)        ,intent(in)           :: model    ! used to construct env varible name
    integer(SHR_KIND_IN),intent(out),optional :: rcodeOut ! Return error code
    !EOP

    !--- local ---
    character(SHR_KIND_CL) :: filename ! namelist file to read
    character(SHR_KIND_CL) :: stdout   ! open unit 6 to this file
    integer  (SHR_KIND_IN) :: rcode    ! return code

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_chStdOut) '
    character(*),parameter :: F00   = "('(shr_file_chStdOut) ',4a)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    call shr_file_stdioReadNL( model, filename, stdoutOut=stdout, &
         rcodeOut=rcode )
    if (stdout /= "nochange") then
       close(6)
       open(unit=6,file=stdout,position='APPEND')
       if (s_loglev > 0) write(s_logunit,F00) "read ",trim(filename),  &
            ': unit 6 connected to ',trim(stdout)
       call shr_sys_flush(s_logunit)
    else
       if (s_loglev > 0) write(s_logunit,F00) "read ",trim(filename),  &
            ': unit 6 has *not* been redirected'
       rcode = 1
    endif

    if ( present(rcodeOut)   ) rcodeOut = rcode

  END SUBROUTINE shr_file_chStdOut

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_stdioReadNL -- read in stdio namelist
  !
  ! !DESCRIPTION:
  !   Read in the stdio namelist for any given model type. Return any of the
  ! needed input namelist variables as optional arguments. Return "nochange" in
  ! dir, stdin, or stdout if shouldn't change.
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_stdioReadNL( model, filename, dirOut, stdinOut, stdoutOut, &
       NLFileOut, rcodeOut )

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    character(*)          ,intent(in)           :: model     ! used to construct env varible name
    character(SHR_KIND_CL),intent(out)          :: filename  ! nml file to read from unit 5
    character(SHR_KIND_CL),intent(out),optional :: NLFileOut ! open unit 6 to this file
    character(SHR_KIND_CL),intent(out),optional :: dirOut    ! directory to cd to
    character(SHR_KIND_CL),intent(out),optional :: stdinOut  ! open unit 5 to this file
    character(SHR_KIND_CL),intent(out),optional :: stdoutOut ! open unit 6 to this file
    integer  (SHR_KIND_IN),intent(out),optional :: rcodeOut  ! return code

    !EOP

    !--- local ---
    logical                :: exists   ! true iff file exists
    character(SHR_KIND_CL) :: dir      ! directory to cd to
    character(SHR_KIND_CL) :: stdin    ! open unit 5 to this file
    character(SHR_KIND_CL) :: stdout   ! open unit 6 to this file
    character(SHR_KIND_CL) :: NLFile   ! namelist file to read seperately
    integer  (SHR_KIND_IN) :: rcode    ! return code
    integer  (SHR_KIND_IN) :: unit     ! Unit to read from

    namelist / stdio / dir,stdin,stdout,NLFile

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_stdioReadNL) '
    character(*),parameter :: F00   = "('(shr_file_stdioReadNL) ',4a)"
    character(*),parameter :: F01   = "('(shr_file_stdioReadNL) ',3a,i6)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !
    !-------------------------------------------------------------------------------

    rcode  = 0
    dir    = "nochange"
    stdin  = "nochange"
    stdout = "nochange"
    NLFile = " "

    filename = trim(model)//"_stdio.nml"  ! eg. file="cpl_stdio.nml"
    inquire(file=filename,exist=exists)

    if (.not. exists) then
       if (s_loglev > 0) write(s_logunit,F00) "file ",trim(filename),&
            & " doesn't exist, can not read stdio namelist from it"
       rcode = 9
    else
       unit = shr_file_getUnit()
       open (unit,file=filename,action="READ")
       read (unit,nml=stdio,iostat=rcode)
       close(unit)
       call shr_file_freeUnit( unit )
       if (rcode /= 0) then
          write(s_logunit,F01) 'ERROR: reading ',trim(filename),': iostat=',rcode
          call shr_sys_abort(subName//" ERROR reading "//trim(filename) )
       end if
    endif
    if ( len_trim(NLFile) > 0 .and. trim(stdin) /= "nochange" )then
       write(s_logunit,F00) "Error: input namelist:"
       write(s_logunit,nml=stdio)
       call shr_sys_abort(subName//" ERROR trying to both redirect AND "// &
            "open namelist filename" )
    end if
    if ( present(NLFileOut) ) NLFileOut = NLFile
    if ( present(dirOut)    ) dirOut    = dir
    if ( present(stdinOut)  ) stdinOut  = stdin
    if ( present(stdoutOut) ) stdoutOut = stdout
    if ( present(rcodeOut)  ) rcodeOut  = rcode

  END SUBROUTINE shr_file_stdioReadNL

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_setIO -- read in stdio namelist
  !
  ! !DESCRIPTION:
  !   This opens a namelist file specified as an argument and then opens
  !   a log file associated with the unit argument.  This may be extended
  !   in the future.
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_setIO( nmlfile, funit)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    character(len=*)    ,intent(in)  :: nmlfile  ! namelist filename
    integer(SHR_KIND_IN),intent(in)  :: funit    ! unit number for log file

    !EOP

    !--- local ---
    logical                :: exists   ! true if file exists
    character(SHR_KIND_CL) :: diri     ! directory to cd to
    character(SHR_KIND_CL) :: diro     ! directory to cd to
    character(SHR_KIND_CL) :: logfile  ! open unit 6 to this file
    integer(SHR_KIND_IN)   :: unit     ! unit number
    integer(SHR_KIND_IN)   :: rcode    ! error code

    namelist / modelio / diri,diro,logfile

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_setIO) '
    character(*),parameter :: F00   = "('(shr_file_setIO) ',4a)"
    character(*),parameter :: F01   = "('(shr_file_setIO) ',3a,i6)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !
    !-------------------------------------------------------------------------------

    diri = "."
    diro = "."
    logfile = ""

    inquire(file=nmlfile,exist=exists)

    if (.not. exists) then
       if (s_loglev > 0) write(s_logunit,F00) "file ",trim(nmlfile)," nonexistent"
       return
    else
       unit = shr_file_getUnit()
       open (unit,file=nmlfile,action="READ")
       read (unit,nml=modelio,iostat=rcode)
       close(unit)
       call shr_file_freeUnit( unit )
       if (rcode /= 0) then
          write(s_logunit,F01) 'ERROR: reading ',trim(nmlfile),': iostat=',rcode
          call shr_sys_abort(subName//" ERROR reading "//trim(nmlfile) )
       end if
    endif

    if (len_trim(logfile) > 0) then
       open(funit,file=trim(diro)//"/"//trim(logfile))
    else
       if (s_loglev > 0) write(s_logunit,F00) "logfile not opened"
    endif

  END SUBROUTINE shr_file_setIO

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_setLogUnit -- Set the Log I/O Unit number
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_setLogUnit(unit)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    integer(SHR_KIND_IN),intent(in) :: unit     ! new unit number

    !EOP

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_setLogUnit) '
    character(*),parameter :: F00   = "('(shr_file_setLogUnit) ',4a)"

    !-------------------------------------------------------------------------------
    ! Notes: Caller must be sure it's a valid unit number
    !-------------------------------------------------------------------------------

    if (s_loglev > 1 .and. s_logunit-unit /= 0) then
       write(s_logunit,*) subName,': reset log unit number from/to ',s_logunit, unit
       write(     unit,*) subName,': reset log unit number from/to ',s_logunit, unit
    endif

    s_logunit = unit

  END SUBROUTINE shr_file_setLogUnit

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_setLogLevel -- Set the Log I/O Unit number
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_setLogLevel(newlevel)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    integer(SHR_KIND_IN),intent(in) :: newlevel     ! new log level

    !EOP

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_setLogLevel) '
    character(*),parameter :: F00   = "('(shr_file_setLogLevel) ',4a)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    if (s_loglev+newlevel > 2 .and. s_loglev-newlevel /= 0) &
         write(s_logunit,*) subName,': reset log level from/to ',s_loglev, newlevel

    s_loglev = newlevel

  END SUBROUTINE shr_file_setLogLevel

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_getLogUnit -- Set the Log I/O Unit number
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_getLogUnit(unit)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    integer(SHR_KIND_IN),intent(out) :: unit     ! new unit number

    !EOP

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_getLogUnit) '
    character(*),parameter :: F00   = "('(shr_file_getLogUnit) ',4a)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    unit = s_logunit

  END SUBROUTINE shr_file_getLogUnit

  !===============================================================================
  !BOP ===========================================================================
  !
  ! !IROUTINE: shr_file_getLogLevel -- Set the Log I/O Unit number
  !
  ! !INTERFACE: ------------------------------------------------------------------

  SUBROUTINE shr_file_getLogLevel(curlevel)

    implicit none

    ! !INPUT/OUTPUT PARAMETERS:

    integer(SHR_KIND_IN),intent(out) :: curlevel     ! new log level

    !EOP

    !--- formats ---
    character(*),parameter :: subName = '(shr_file_getLogLevel) '
    character(*),parameter :: F00   = "('(shr_file_getLogLevel) ',4a)"

    !-------------------------------------------------------------------------------
    ! Notes:
    !-------------------------------------------------------------------------------

    curlevel = s_loglev

  END SUBROUTINE shr_file_getLogLevel

  !===============================================================================
  !===============================================================================

END MODULE shr_file_mod
