From 7f79dc66e5ddc9ff97b02bde7be62ba41426098b Mon Sep 17 00:00:00 2001
From: Jim Edwards <jedwards@ucar.edu>
Date: Fri, 20 Oct 2023 15:06:46 -0600
Subject: [PATCH] need to add shr_nl_mod for standalone builds

---
 share/CMakeLists.txt |  1 +
 share/shr_nl_mod.F90 | 88 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 89 insertions(+)
 create mode 100644 share/shr_nl_mod.F90

diff --git a/share/CMakeLists.txt b/share/CMakeLists.txt
index 215847da..fa5f4844 100644
--- a/share/CMakeLists.txt
+++ b/share/CMakeLists.txt
@@ -5,6 +5,7 @@ set (GenF90_SRCS shr_infnan_mod.F90
                  shr_assert_mod.F90)
 
 add_library(cdeps_share  ${GenF90_SRCS}
+                         shr_nl_mod.F90
                          glc_elevclass_mod.F90
                          shr_timer_mod.F90
                          shr_cal_mod.F90
diff --git a/share/shr_nl_mod.F90 b/share/shr_nl_mod.F90
new file mode 100644
index 00000000..f06f2185
--- /dev/null
+++ b/share/shr_nl_mod.F90
@@ -0,0 +1,88 @@
+module shr_nl_mod
+
+! Utilities for namelist reading
+! Adapted Fall 2012 from CAM's namelist_utils.
+
+implicit none
+private
+
+save
+
+public :: &
+     shr_nl_find_group_name ! seek through a file to find a specified namelist
+
+contains
+
+! This routine probably discards more error code information than it needs to.
+
+subroutine shr_nl_find_group_name(unit, group, status)
+
+  use shr_string_mod, only: shr_string_toLower
+
+!---------------------------------------------------------------------------------------
+! Purpose:
+! Search a file that contains namelist input for the specified namelist group name.
+! Leave the file positioned so that the current record is the first record of the
+! input for the specified group.
+!
+! Method:
+! Read the file line by line.  Each line is searched for an '&' which may only
+! be preceded by blanks, immediately followed by the group name which is case
+! insensitive.  If found then backspace the file so the current record is the
+! one containing the group name and return success.  Otherwise return -1.
+!
+! Author:  B. Eaton, August 2007
+!---------------------------------------------------------------------------------------
+
+   integer,          intent(in)  :: unit     ! fortran unit attached to file
+   character(len=*), intent(in)  :: group    ! namelist group name
+   integer,          intent(out) :: status   ! 0 for success, -1 if group name not found
+
+   ! Local variables
+
+   integer           :: len_grp
+   integer           :: ios    ! io status
+   character(len=80) :: inrec  ! first 80 characters of input record
+   character(len=80) :: inrec2 ! left adjusted input record
+   character(len=len(group)) :: lc_group
+
+   !---------------------------------------------------------------------------
+
+   len_grp = len_trim(group)
+   lc_group = shr_string_toLower(group)
+
+   ios = 0
+   do while (ios <= 0)
+
+      read(unit, '(a)', iostat=ios, end=100) inrec
+
+      if (ios <= 0) then  ! ios < 0  indicates an end of record condition
+
+         ! look for group name in this record
+
+         ! remove leading blanks
+         inrec2 = adjustl(inrec)
+
+         ! check for leading '&'
+         if (inrec2(1:1) == '&') then
+
+            ! check for case insensitive group name
+            if (trim(lc_group) == shr_string_toLower(inrec2(2:len_grp+1))) then
+
+               ! found group name.  backspace to leave file position at this record
+               backspace(unit)
+               status = 0
+               return
+
+            end if
+         end if
+      end if
+
+   end do
+
+   100 continue  ! end of file processing
+   status = -1
+
+end subroutine shr_nl_find_group_name
+
+end module shr_nl_mod