From 715f5f6f33cb925815b084add7cf54dcf24d909f Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sat, 3 Feb 2024 10:02:00 -0700
Subject: [PATCH 01/12] updated CI

---
 .github/workflows/developer.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/developer.yml b/.github/workflows/developer.yml
index 9cf92586..2df9d26c 100644
--- a/.github/workflows/developer.yml
+++ b/.github/workflows/developer.yml
@@ -146,7 +146,7 @@ jobs:
 
     - name: upload-test-coverage
       if: matrix.config == 'asan/code coverage'
-      uses: actions/upload-artifact@v3
+      uses: actions/upload-artifact@v4
       with:
         name: g2-test-coverage
         path: |

From 925b994014d6b60121ccea49fb60e1fce5e99ce6 Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sat, 3 Feb 2024 11:15:54 -0700
Subject: [PATCH 02/12] working on index

---
 src/g2index.F90 | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/src/g2index.F90 b/src/g2index.F90
index 07cbeeb7..04cbe615 100644
--- a/src/g2index.F90
+++ b/src/g2index.F90
@@ -212,6 +212,7 @@ SUBROUTINE GETG2I(LUGI, CBUF, NLEN, NNUM, IRET)
   INTEGER, INTENT(OUT) :: NLEN, NNUM, IRET
   CHARACTER CHEAD*162
   integer :: ios, istat, lbuf, lhead, nskp
+  integer :: index_version
 
   NULLIFY(CBUF)
   NLEN = 0
@@ -219,7 +220,7 @@ SUBROUTINE GETG2I(LUGI, CBUF, NLEN, NNUM, IRET)
   IRET = 4
   CALL BAREAD(LUGI, 0, 162, LHEAD, CHEAD)
   IF (LHEAD .EQ. 162 .AND. CHEAD(42:47) .EQ. 'GB2IX1') THEN
-     READ(CHEAD(82:162), '(8X, 3I10, 2X, A40)', IOSTAT = IOS) NSKP, NLEN, NNUM
+     READ(CHEAD(82:162), '(2X, I1, 5X, 3I10, 2X, A40)', IOSTAT = IOS) index_version, NSKP, NLEN, NNUM
      IF (IOS .EQ. 0) THEN
         ALLOCATE(CBUF(NLEN), STAT = ISTAT)    ! ALLOCATE SPACE FOR CBUF
         IF (ISTAT .NE. 0) THEN

From 0e1abb9c1578fc8c1b43db3997483fe1f7ffdfcd Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sun, 4 Feb 2024 05:57:29 -0700
Subject: [PATCH 03/12] more testing

---
 src/g2_gbytesc.F90    |  4 +--
 tests/test_gbytec.F90 | 77 +++++++++++++++++++++++++++----------------
 2 files changed, 51 insertions(+), 30 deletions(-)

diff --git a/src/g2_gbytesc.F90 b/src/g2_gbytesc.F90
index 4c76cf29..de841bd0 100644
--- a/src/g2_gbytesc.F90
+++ b/src/g2_gbytesc.F90
@@ -11,7 +11,7 @@
 !> has more elements, use g2_sbytesc().
 !>
 !> @param[in] in Array input.
-!> @param[out] iout Unpacked array output.
+!> @param[inout] iout Unpacked array output.
 !> @param[in] iskip Initial number of bits to skip.
 !> @param[in] nbits Number of bits of each integer in IN to take.
 !>
@@ -32,7 +32,7 @@ end subroutine g2_gbytec
 !> This should be used when input array IN has only one element. If IN
 !> has more elements, use G2_SBYTESC().
 !>
-!> @param[out] out packed array output
+!> @param[inout] out packed array output
 !> @param[in] in unpacked array input
 !> @param[in] iskip initial number of bits to skip
 !> @param[in] nbits Number of bits of each integer in OUT to fill.
diff --git a/tests/test_gbytec.F90 b/tests/test_gbytec.F90
index cfb49fb0..2038a8a9 100644
--- a/tests/test_gbytec.F90
+++ b/tests/test_gbytec.F90
@@ -11,6 +11,7 @@ program test_gbytec
   character*1 :: out5(5)
   character*1 :: out8(8)
   character*1 :: out10(10)
+  integer :: in4(4), in1(1)
   integer, parameter :: n = 1
   integer :: in(n)
   real :: r_in(n)
@@ -25,15 +26,19 @@ program test_gbytec
   integer :: i
   integer :: num
   
-  print *, 'Testing g2_gbytesc.f subroutines.'
+  print *, 'Testing g2_gbytesc.F90 subroutines.'
 
-  print *, 'Testing g2_sbytec()...'
+  print *, '   testing g2_sbytec()...'
   in(1) = 3
   out(1) = char(0)
   call g2_sbytec(out, in, iskip, nbits)
   if (ichar(out(1)) .ne. in(1)) stop 10
 
-  print *, 'Testing g2_sbytesc()...'
+  print *, '   testing g2_gbytec()...'
+  call g2_gbytec(out, in, iskip, nbits)
+  if (ichar(out(1)) .ne. in(1)) stop 11
+
+  print *, '   testing g2_sbytesc()...'
   in(1) = 3
   out(1) = char(0)
   call g2_sbytesc(out, in, iskip, nbits, nskip, n)
@@ -41,7 +46,7 @@ program test_gbytec
 
   ! This will pack the numbers 1 and 2 into the first two chars of the
   ! buffer. The rest of the output buffer will remain zeros.
-  print *, 'Testing g2_sbytesc() packing 2 values...'
+  print *, '   testing g2_sbytesc() packing 2 values...'
   in2(1) = 1
   in2(2) = 2
   do i = 1, 8
@@ -58,7 +63,7 @@ program test_gbytec
   end do
 
   ! Now pack 5 values into the 5 character array out5.
-  print *, 'Testing g2_sbytesc() packing 5 values...'
+  print *, '   testing g2_sbytesc() packing 5 values...'
   in5(1) = 1
   in5(2) = 2
   in5(3) = 3
@@ -76,7 +81,7 @@ program test_gbytec
 
   ! Now pack 5 values into the 10 character array out10. Skip every
   ! other byte in the output.
-  print *, 'Testing g2_sbytesc() packing 5 values, skipping every other byte...'
+  print *, '   testing g2_sbytesc() packing 5 values, skipping every other byte...'
   nbits = 8
   nskip = 0
   do i = 1, 10
@@ -88,32 +93,45 @@ program test_gbytec
      if (mod(i, 2) .gt. 0) then
         if (ichar(out10(i)) .ne. in5(int(i/2) + 1)) stop 51;
      else
-        if (ichar(out10(i)) .ne. 0) stop 50;
+        if (ichar(out10(i)) .ne. 0) stop 52;
      endif
   end do
 
-  print *, 'Testing g2_sbytec() with iskip of 1...'
+  print *, '   testing g2_sbytec() with iskip of 1...'
   in(1) = 1
   out(1) = char(0)
   call g2_sbytec(out, in, 1, 6)
-  ! print '(z2.2)', out(1)  
-  if (ichar(out(1)) .ne. 2) stop 20
+  if (ichar(out(1)) .ne. 2) stop 53
 
-  print *, 'Testing g2_sbytesc() with a small array...'
+  print *, '   testing g2_sbytesc() with a size 4 output array...'
   iskip = 0
   nbits = 32
   nskip = 0
   num = 1
   in(1) = 1
   call g2_sbytesc(out4, in, iskip, nbits, nskip, num)
-  if (ichar(out4(1)) .ne. 0 .and. ichar(out4(2)) .ne. 0 .and. ichar(out4(3)) .ne. 0 .and. ichar(out4(4)) .ne. 1) stop 50
-  !print '(z2.2)', out4(1)  
+  if (ichar(out4(1)) .ne. 0 .and. ichar(out4(2)) .ne. 0 .and. &
+       ichar(out4(3)) .ne. 0 .and. ichar(out4(4)) .ne. 1) stop 60
+
+  print *, '   now unpack into 4 ints with g2_gbytesc()...'
+  call g2_gbytesc(out4, in4, iskip, 8, 0, 4)
+  do i = 1, 4
+     if (i < 4) then
+        if (in4(i) .ne. 0) stop 61
+     else
+        if (in4(i) .ne. 1) stop 62
+     endif
+  end do
 
+  print *, '   now unpack into 1 int with g2_gbytesc()...'
+  call g2_gbytesc(out4, in1, iskip, 32, 0, 1)
+  if (in1(1) .ne. 1) stop 70
+  
   ! For this test to pass the -fallow-argument-mismatch flag must be
   ! used, because I am passing in a real array instead of an int array
   ! for the in parameter. This is how g2_sbytesc() is called in
   ! addfield.F90.
-  print *, 'Testing g2_sbytesc() with a real array (size 1) instead of an int array...'
+  print *, '   testing g2_sbytesc() with a real array (size 1) instead of an int array...'
   iskip = 0
   nbits = 32
   nskip = 0
@@ -122,14 +140,13 @@ program test_gbytec
   call g2_sbytesc(out4, r_in, iskip, nbits, nskip, num)
   ! Note that the 32-bit IEEE representation of 1.0 is 3f800000. The
   ! decimal for 3f is 63, the decimal for 80 is 128.
-  if (ichar(out4(1)) .ne. 63 .and. ichar(out4(2)) .ne. 128 .and. ichar(out4(3)) .ne. 0 .and. ichar(out4(4)) .ne. 0) stop 50
+  if (ichar(out4(1)) .ne. 63 .and. ichar(out4(2)) .ne. 128 .and. &
+       ichar(out4(3)) .ne. 0 .and. ichar(out4(4)) .ne. 0) stop 80
   ! print '(z2.2)', out4(1)  
-  ! print '(z2.2)', out4(2)  
-  ! print '(z2.2)', out4(3)  
-  ! print '(z2.2)', out4(4)
 
-  ! This test is the same as above, but does not require the -fallow-argument-mismatch flag.
-  print *, 'Testing g2_sbytesc() with a real array (size 1) instead of an int array, using transfer() intrinsic...'
+  ! This test is the same as above, but does not require the
+  ! -fallow-argument-mismatch flag.
+  print *, '   testing g2_sbytesc() with a size 1 real array instead of an int array, using transfer()...'
   iskip = 0
   nbits = 32
   nskip = 0
@@ -139,14 +156,14 @@ program test_gbytec
   call g2_sbytesc(out4, in, iskip, nbits, nskip, num)
   ! Note that the 32-bit IEEE representation of 1.0 is 3f800000. The
   ! decimal for 3f is 63, the decimal for 80 is 128.
-  if (ichar(out4(1)) .ne. 63 .and. ichar(out4(2)) .ne. 128 .and. ichar(out4(3)) .ne. 0 .and. ichar(out4(4)) .ne. 0) stop 50
-  ! print '(z2.2)', out4(1)  
+  if (ichar(out4(1)) .ne. 63 .and. ichar(out4(2)) .ne. 128 .and. &
+       ichar(out4(3)) .ne. 0 .and. ichar(out4(4)) .ne. 0) stop 90
 
   ! For this test to pass the -fallow-argument-mismatch flag must be
   ! used, because I am passing in a real array instead of an int array
   ! for the in parameter. This is how g2_sbytesc() is called in
   ! addfield.F90.
-  print *, 'Testing g2_sbytesc() with a real array instead of an int array...'
+  print *, '   testing g2_sbytesc() with a real array instead of an int array...'
   iskip = 0
   nbits = 32
   nskip = 0
@@ -156,12 +173,14 @@ program test_gbytec
   call g2_sbytesc(out8, r_in2, iskip, nbits, nskip, num)
   ! Note that the 32-bit IEEE representation of 1.0 is 3f800000. The
   ! decimal for 3f is 63, the decimal for 80 is 128.
-  if (ichar(out8(1)) .ne. 63 .and. ichar(out8(2)) .ne. 128 .and. ichar(out8(3)) .ne. 0 .and. ichar(out8(4)) .ne. 0) stop 50
-  if (ichar(out8(5)) .ne. 63 .and. ichar(out8(6)) .ne. 128 .and. ichar(out8(7)) .ne. 0 .and. ichar(out8(8)) .ne. 0) stop 50
+  if (ichar(out8(1)) .ne. 63 .and. ichar(out8(2)) .ne. 128 .and. &
+       ichar(out8(3)) .ne. 0 .and. ichar(out8(4)) .ne. 0) stop 100
+  if (ichar(out8(5)) .ne. 63 .and. ichar(out8(6)) .ne. 128 .and. &
+       ichar(out8(7)) .ne. 0 .and. ichar(out8(8)) .ne. 0) stop 110
   ! print '(z2.2)', out8(1)  
 
   ! This test is the same as above, but does not require the -fallow-argument-mismatch flag.
-  print *, 'Testing g2_sbytesc() with a real array instead of an int array, using transfer() intrinsic...'
+  print *, '   testing g2_sbytesc() with a real array instead of an int array, using transfer() intrinsic...'
   iskip = 0
   nbits = 32
   nskip = 0
@@ -172,8 +191,10 @@ program test_gbytec
   call g2_sbytesc(out8, in2, iskip, nbits, nskip, num)
   ! Note that the 32-bit IEEE representation of 1.0 is 3f800000. The
   ! decimal for 3f is 63, the decimal for 80 is 128.
-  if (ichar(out4(1)) .ne. 63 .and. ichar(out4(2)) .ne. 128 .and. ichar(out4(3)) .ne. 0 .and. ichar(out4(4)) .ne. 0) stop 50
-  if (ichar(out8(5)) .ne. 63 .and. ichar(out8(6)) .ne. 128 .and. ichar(out8(7)) .ne. 0 .and. ichar(out8(8)) .ne. 0) stop 50
+  if (ichar(out4(1)) .ne. 63 .and. ichar(out4(2)) .ne. 128 .and. &
+       ichar(out4(3)) .ne. 0 .and. ichar(out4(4)) .ne. 0) stop 120
+  if (ichar(out8(5)) .ne. 63 .and. ichar(out8(6)) .ne. 128 .and. &
+       ichar(out8(7)) .ne. 0 .and. ichar(out8(8)) .ne. 0) stop 130
   ! print '(z2.2)', out4(1)  
 
   print *, 'SUCCESS!'

From 716abd647dcd9f3f0970194af194ca7a6aa1d549 Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sun, 4 Feb 2024 06:23:21 -0700
Subject: [PATCH 04/12] more testing

---
 tests/test_gbytec.F90 | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/tests/test_gbytec.F90 b/tests/test_gbytec.F90
index 2038a8a9..1c692dda 100644
--- a/tests/test_gbytec.F90
+++ b/tests/test_gbytec.F90
@@ -11,6 +11,7 @@ program test_gbytec
   character*1 :: out5(5)
   character*1 :: out8(8)
   character*1 :: out10(10)
+  character*1 :: out256(256)
   integer :: in4(4), in1(1)
   integer, parameter :: n = 1
   integer :: in(n)
@@ -25,6 +26,7 @@ program test_gbytec
   integer :: nskip = 0
   integer :: i
   integer :: num
+  integer(kind = 8) :: in8(1), in8_1(1), in84(4), in84_1(4)
   
   print *, 'Testing g2_gbytesc.F90 subroutines.'
 
@@ -197,6 +199,21 @@ program test_gbytec
        ichar(out8(7)) .ne. 0 .and. ichar(out8(8)) .ne. 0) stop 130
   ! print '(z2.2)', out4(1)  
 
+  print *, '   testing g2_sbytec() with 64-bit int...'
+  in8(1) = 1
+  do i = 1, 8
+     out8(i) = char(0)
+  end do
+  call g2_sbytec(out8, in8, iskip, 64)
+  do i = 1, 8
+     !print '(z2.2)', out8(i)
+     if (i .lt. 8) then
+        if (ichar(out8(i)) .ne. 0) stop 140
+     else
+        if (ichar(out8(i)) .ne. 1) stop 140
+     endif
+  end do
+
   print *, 'SUCCESS!'
 
 end program test_gbytec

From e97583e7d543d454cbec6d763c5797dd25eaa798 Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sun, 4 Feb 2024 06:23:49 -0700
Subject: [PATCH 05/12] more testing

---
 tests/test_gbytec.F90 | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/tests/test_gbytec.F90 b/tests/test_gbytec.F90
index 1c692dda..2c9cadba 100644
--- a/tests/test_gbytec.F90
+++ b/tests/test_gbytec.F90
@@ -214,6 +214,11 @@ program test_gbytec
      endif
   end do
 
+  print *, '   now unpack into 1 64-bit int with g2_gbytesc()...'
+  call g2_gbytesc(out8, in8_1, iskip, 64, 0, 1)
+  print *, in8_1
+  if (in8_1(1) .ne. in8(1)) stop 150
+
   print *, 'SUCCESS!'
 
 end program test_gbytec

From 6fe8b94c201f9ffcb125a6468ada05c14cfda01c Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sun, 4 Feb 2024 06:24:11 -0700
Subject: [PATCH 06/12] more testing

---
 tests/test_gbytec.F90 | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/tests/test_gbytec.F90 b/tests/test_gbytec.F90
index 2c9cadba..49d4d7a9 100644
--- a/tests/test_gbytec.F90
+++ b/tests/test_gbytec.F90
@@ -219,6 +219,24 @@ program test_gbytec
   print *, in8_1
   if (in8_1(1) .ne. in8(1)) stop 150
 
+  print *, '   testing g2_sbytec() with 64-bit int array of size 4...'
+  do i = 1, 4
+     in84(i) = 1
+  end do
+  do i = 1, 256
+     out256(i) = char(0)
+  end do
+  print *, in84
+  call g2_sbytec(out256, in84, iskip, 64, 0, 4)
+  do i = 1, 256
+     print '(i3, x, z2.2)', i, out8(i)
+     ! if (i .lt. 8) then
+     !    if (ichar(out8(i)) .ne. 0) stop 140
+     ! else
+     !    if (ichar(out8(i)) .ne. 1) stop 140
+     ! endif
+  end do
+
   print *, 'SUCCESS!'
 
 end program test_gbytec

From 1c13fd4531513aef383d3ec61bd502f6b1a20bab Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sun, 4 Feb 2024 06:42:03 -0700
Subject: [PATCH 07/12] more testing

---
 tests/test_gbytec.F90 | 49 ++++++++++++++++++++++++++++++++-----------
 1 file changed, 37 insertions(+), 12 deletions(-)

diff --git a/tests/test_gbytec.F90 b/tests/test_gbytec.F90
index 49d4d7a9..6064e2e2 100644
--- a/tests/test_gbytec.F90
+++ b/tests/test_gbytec.F90
@@ -11,7 +11,8 @@ program test_gbytec
   character*1 :: out5(5)
   character*1 :: out8(8)
   character*1 :: out10(10)
-  character*1 :: out256(256)
+  character*1 :: out16(16)
+  character*1 :: out32(32)
   integer :: in4(4), in1(1)
   integer, parameter :: n = 1
   integer :: in(n)
@@ -26,6 +27,7 @@ program test_gbytec
   integer :: nskip = 0
   integer :: i
   integer :: num
+  integer(kind = 4) :: in44(4), in44_1(4)
   integer(kind = 8) :: in8(1), in8_1(1), in84(4), in84_1(4)
   
   print *, 'Testing g2_gbytesc.F90 subroutines.'
@@ -215,27 +217,50 @@ program test_gbytec
   end do
 
   print *, '   now unpack into 1 64-bit int with g2_gbytesc()...'
+  in8_1(1) = 0
   call g2_gbytesc(out8, in8_1, iskip, 64, 0, 1)
-  print *, in8_1
   if (in8_1(1) .ne. in8(1)) stop 150
 
+  print *, '   testing g2_sbytec() with 32-bit int array of size 4...'
+  do i = 1, 4
+     in44(i) = 1
+  end do
+  do i = 1, 16
+     out16(i) = char(0)
+  end do
+  call g2_sbytesc(out16, in44, iskip, 32, 0, 4)
+  do i = 1, 16
+     print '(i3, x, z2.2)', i, out16(i)
+  end do
+  
+  print *, '   now unpack into 4 32-bit ints with g2_gbytesc()...'
+  do i = 1, 4
+     in44_1(i) = 0
+  end do
+  call g2_gbytesc(out16, in44_1, iskip, 32, 0, 4)
+  do i = 1, 4
+     if (in44_1(i) .ne. in44(i)) stop 160
+  end do
+
   print *, '   testing g2_sbytec() with 64-bit int array of size 4...'
   do i = 1, 4
      in84(i) = 1
   end do
-  do i = 1, 256
-     out256(i) = char(0)
+  do i = 1, 32
+     out32(i) = char(0)
   end do
   print *, in84
-  call g2_sbytec(out256, in84, iskip, 64, 0, 4)
-  do i = 1, 256
-     print '(i3, x, z2.2)', i, out8(i)
-     ! if (i .lt. 8) then
-     !    if (ichar(out8(i)) .ne. 0) stop 140
-     ! else
-     !    if (ichar(out8(i)) .ne. 1) stop 140
-     ! endif
+  call g2_sbytesc(out32, in84, iskip, 64, 0, 4)
+  do i = 1, 32
+     print '(i3, x, z2.2)', i, out32(i)
+  end do
+
+  print *, '   now unpack into 4 64-bit ints with g2_gbytesc()...'
+  do i = 1, 4
+     in84_1(i) = 0
   end do
+  call g2_gbytesc(out32, in84_1, iskip, 64, 0, 4)
+  print *, in84_1
 
   print *, 'SUCCESS!'
 

From 56ece6fb6235775fbafca0993946fe09374c2a94 Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sun, 4 Feb 2024 13:15:10 -0700
Subject: [PATCH 08/12] working on index version 2

---
 src/g2index.F90 | 104 ++++++++++++++++++++++++++++++++++--------------
 1 file changed, 74 insertions(+), 30 deletions(-)

diff --git a/src/g2index.F90 b/src/g2index.F90
index 04cbe615..eefdb6d2 100644
--- a/src/g2index.F90
+++ b/src/g2index.F90
@@ -234,6 +234,49 @@ SUBROUTINE GETG2I(LUGI, CBUF, NLEN, NNUM, IRET)
   ENDIF
 END SUBROUTINE GETG2I
 
+!> Generate an index record for a message in a GRIB2 file.
+!>
+!> The index record contains byte offsets to the message, it's length,
+!> and byte offsets within the message to each section. The index file
+!> record format is documented in subroutine ixgb2().
+!>
+!> This is the legacy function, which always creates version 1 index
+!> files. To create index files of version 1 or 2, use getg2i2r().
+!>
+!> @param[in] lugb Unit of the unblocked GRIB file. Must
+!> be opened by [baopen() or baopenr()]
+!> (https://noaa-emc.github.io/NCEPLIBS-bacio/).
+!> @param[in] msk1 Number of bytes to search for first message.
+!> @param[in] msk2 Number of bytes to search for other messages.
+!> @param[in] mnum Number of GRIB messages to skip (usually 0).
+!> @param[in] idxver Index version, 1 for legacy, 2 for files > 2 GB.
+!> @param[out] cbuf Pointer to a buffer that will get the index
+!> records. If any memory is associated with cbuf when this subroutine
+!> is called, cbuf will be nullified in the subroutine. Initially cbuf
+!> will get an allocation of 5000 bytes. realloc() will be used to
+!> increase the size if necessary. Users must free memory that cbuf
+!> points to when cbuf is no longer needed.
+!> @param[out] nlen Total length of index record buffer in bytes.
+!> @param[out] nnum Number of index records, zero if no GRIB
+!> messages are found.
+!> @param[out] nmess Last GRIB message in file successfully processed
+!> @param[out] iret Return code.
+!> - 0 No error.
+!> - 1 Not enough memory available to hold full index buffer.
+!> - 2 Not enough memory to allocate initial index buffer.
+!> - 3 Error deallocating memory.
+!>
+!> @author Mark Iredell @date 1995-10-31
+subroutine getg2ir(lugb, msk1, msk2, mnum, cbuf, nlen, nnum, nmess, iret)
+  use re_alloc              ! needed for subroutine realloc
+  implicit none
+  character(len = 1), pointer, dimension(:) :: cbuf
+  integer, intent(in) :: lugb, msk1, msk2, mnum
+  integer, intent(out) :: nlen, nnum, nmess, iret
+
+  call getg2i2r(lugb, msk1, msk2, mnum, 1, cbuf, nlen, nnum, nmess, iret)
+end subroutine getg2ir
+
 !> Generate an index record for a message in a GRIB2 file.
 !>
 !> The index record contains byte offsets to the message, it's length,
@@ -266,45 +309,46 @@ END SUBROUTINE GETG2I
 !> - 3 Error deallocating memory.
 !>
 !> @author Mark Iredell @date 1995-10-31
-SUBROUTINE GETG2IR(LUGB, MSK1, MSK2, MNUM, CBUF, NLEN, NNUM, NMESS, IRET)
-  USE RE_ALLOC              ! NEEDED FOR SUBROUTINE REALLOC
+subroutine getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, &
+     nnum, nmess, iret)
+  use re_alloc              ! needed for subroutine realloc
   implicit none
 
-  CHARACTER(LEN = 1), POINTER, DIMENSION(:) :: CBUF
-  INTEGER, INTENT(IN) :: LUGB, MSK1, MSK2, MNUM
-  INTEGER, INTENT(OUT) :: NLEN, NNUM, NMESS, IRET
-  CHARACTER(LEN = 1), POINTER, DIMENSION(:) :: CBUFTMP
+  character(len = 1), pointer, dimension(:) :: cbuf
+  integer, intent(in) :: lugb, msk1, msk2, mnum, idxver
+  integer, intent(out) :: nlen, nnum, nmess, iret
+  character(len = 1), pointer, dimension(:) :: cbuftmp
   integer :: nbytes, newsize, next, numfld, m, mbuf, lskip, lgrib
   integer :: istat, iseek, init, iret1
-  PARAMETER(INIT = 50000, NEXT = 10000)
+  parameter(init = 50000, next = 10000)
 
-  INTERFACE      ! REQUIRED FOR CBUF POINTER
-     SUBROUTINE IXGB2(LUGB, LSKIP, LGRIB, CBUF, NUMFLD, MLEN, IRET)
-       INTEGER, INTENT(IN) :: LUGB, LSKIP, LGRIB
-       CHARACTER(LEN = 1), POINTER, DIMENSION(:) :: CBUF
-       INTEGER, INTENT(OUT) :: NUMFLD, MLEN, IRET
-     END SUBROUTINE IXGB2
-  END INTERFACE
+  interface      ! required for cbuf pointer
+     subroutine ixgb2(lugb, lskip, lgrib, cbuf, numfld, mlen, iret)
+       integer, intent(in) :: lugb, lskip, lgrib
+       character(len = 1), pointer, dimension(:) :: cbuf
+       integer, intent(out) :: numfld, mlen, iret
+     end subroutine ixgb2
+  end interface
 
   ! Initialize.
-  IRET = 0
-  NULLIFY(CBUF)
-  MBUF = INIT
-  ALLOCATE(CBUF(MBUF), STAT = ISTAT)    ! Allocate initial space for cbuf.
-  IF (ISTAT .NE. 0) THEN
-     IRET = 2
-     RETURN
-  ENDIF
+  iret = 0
+  nullify(cbuf)
+  mbuf = init
+  allocate(cbuf(mbuf), stat = istat)    ! allocate initial space for cbuf.
+  if (istat .ne. 0) then
+     iret = 2
+     return
+  endif
 
   ! Search for first grib message.
-  ISEEK = 0
-  CALL SKGB(LUGB, ISEEK, MSK1, LSKIP, LGRIB)
-  DO M = 1, MNUM
-     IF(LGRIB.GT.0) THEN
-        ISEEK = LSKIP + LGRIB
-        CALL SKGB(LUGB, ISEEK, MSK2, LSKIP, LGRIB)
-     ENDIF
-  ENDDO
+  iseek = 0
+  call skgb(lugb, iseek, msk1, lskip, lgrib)
+  do m = 1, mnum
+     if(lgrib.gt.0) then
+        iseek = lskip + lgrib
+        call skgb(lugb, iseek, msk2, lskip, lgrib)
+     endif
+  enddo
 
   ! Get index records for every grib message found.
   NLEN = 0

From 54eccff8a428ba9c9932011951ebeec5dabe6f64 Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Sun, 4 Feb 2024 13:57:24 -0700
Subject: [PATCH 09/12] added test

---
 src/g2index.F90        |  39 ++++++++++-----
 tests/test_getg2ir.F90 | 107 ++++++++++++++++++++++++-----------------
 2 files changed, 89 insertions(+), 57 deletions(-)

diff --git a/src/g2index.F90 b/src/g2index.F90
index eefdb6d2..ee388a42 100644
--- a/src/g2index.F90
+++ b/src/g2index.F90
@@ -249,7 +249,6 @@ END SUBROUTINE GETG2I
 !> @param[in] msk1 Number of bytes to search for first message.
 !> @param[in] msk2 Number of bytes to search for other messages.
 !> @param[in] mnum Number of GRIB messages to skip (usually 0).
-!> @param[in] idxver Index version, 1 for legacy, 2 for files > 2 GB.
 !> @param[out] cbuf Pointer to a buffer that will get the index
 !> records. If any memory is associated with cbuf when this subroutine
 !> is called, cbuf will be nullified in the subroutine. Initially cbuf
@@ -273,6 +272,15 @@ subroutine getg2ir(lugb, msk1, msk2, mnum, cbuf, nlen, nnum, nmess, iret)
   character(len = 1), pointer, dimension(:) :: cbuf
   integer, intent(in) :: lugb, msk1, msk2, mnum
   integer, intent(out) :: nlen, nnum, nmess, iret
+  
+  interface      ! required for cbuf pointer
+     subroutine getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, &
+          nnum, nmess, iret)
+       character(len = 1), pointer, dimension(:) :: cbuf
+       integer, intent(in) :: lugb, msk1, msk2, mnum, idxver
+       integer, intent(out) :: nlen, nnum, nmess, iret
+     end subroutine getg2i2r
+  end interface
 
   call getg2i2r(lugb, msk1, msk2, mnum, 1, cbuf, nlen, nnum, nmess, iret)
 end subroutine getg2ir
@@ -283,6 +291,10 @@ end subroutine getg2ir
 !> and byte offsets within the message to each section. The index file
 !> record format is documented in subroutine ixgb2().
 !>
+!> This subroutine is like getg2ir(), but this subroutine can generate
+!> index files in version 1 or 2 format. Use index version 2 for files
+!> > 2 GB.
+!>
 !> @note Subprogram can be called from a multiprocessing environment.
 !> Do not engage the same logical unit from more than one processor.
 !>
@@ -292,6 +304,7 @@ end subroutine getg2ir
 !> @param[in] msk1 Number of bytes to search for first message.
 !> @param[in] msk2 Number of bytes to search for other messages.
 !> @param[in] mnum Number of GRIB messages to skip (usually 0).
+!> @param[in] idxver Index version, 1 for legacy, 2 for files > 2 GB.
 !> @param[out] cbuf Pointer to a buffer that will get the index
 !> records. If any memory is associated with cbuf when this subroutine
 !> is called, cbuf will be nullified in the subroutine. Initially cbuf
@@ -308,7 +321,7 @@ end subroutine getg2ir
 !> - 2 Not enough memory to allocate initial index buffer.
 !> - 3 Error deallocating memory.
 !>
-!> @author Mark Iredell @date 1995-10-31
+!> @author Mark Iredell, Edward Hartnett @date Feb 4, 2024
 subroutine getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, &
      nnum, nmess, iret)
   use re_alloc              ! needed for subroutine realloc
@@ -324,12 +337,14 @@ subroutine getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, &
 
   interface      ! required for cbuf pointer
      subroutine ixgb2(lugb, lskip, lgrib, cbuf, numfld, mlen, iret)
-       integer, intent(in) :: lugb, lskip, lgrib
+       integer :: lugb, lskip, lgrib
        character(len = 1), pointer, dimension(:) :: cbuf
-       integer, intent(out) :: numfld, mlen, iret
+       integer :: numfld, mlen, iret
      end subroutine ixgb2
   end interface
 
+  print *, idxver
+
   ! Initialize.
   iret = 0
   nullify(cbuf)
@@ -387,7 +402,7 @@ end subroutine ixgb2
      ISEEK = LSKIP + LGRIB
      CALL SKGB(LUGB, ISEEK, MSK2, LSKIP, LGRIB)
   ENDDO
-END SUBROUTINE GETG2IR
+END SUBROUTINE GETG2I2R
 
 !> Find information about a GRIB field from the index and fill a @ref
 !> grib_mod::gribfield.
@@ -691,21 +706,21 @@ END SUBROUTINE GETGB2S
 !> - byte kk + 1-  ll the data representation section (drs)
 !> - byte ll + 1-ll + 6 first 6 bytes of the bit map section (bms)
 !>
-!> @param[in] lugb Unit of the unblocked GRIB file. Must
+!> @param lugb Unit of the unblocked GRIB file. Must
 !> be opened by [baopen() or baopenr()]
 !> (https://noaa-emc.github.io/NCEPLIBS-bacio/).
-!> @param[in] lskip Number of bytes to skip before GRIB message.
-!> @param[in] lgrib Number of bytes in GRIB message. When subroutine is
+!> @param lskip Number of bytes to skip before GRIB message.
+!> @param lgrib Number of bytes in GRIB message. When subroutine is
 !> called, this must be set to the size of the cbuf buffer.
-!> @param[out] cbuf Pointer to a buffer that will get the index
+!> @param cbuf Pointer to a buffer that will get the index
 !> records. If any memory is associated with cbuf when this subroutine
 !> is called, cbuf will be nullified in the subroutine. Initially cbuf
 !> will get an allocation of 5000 bytes. realloc() will be used to
 !> increase the size if necessary. Users must free memory that cbuf
 !> points to when cbuf is no longer needed.
-!> @param[out] numfld Number of index records created.
-!> @param[out] mlen Total length of all index records.
-!> @param[out] iret Return code
+!> @param numfld Number of index records created.
+!> @param mlen Total length of all index records.
+!> @param iret Return code
 !> - 0 No error
 !> - 1 Not enough memory available to hold full index buffer.
 !> - 2 I/O error in read.
diff --git a/tests/test_getg2ir.F90 b/tests/test_getg2ir.F90
index 268817ac..1323d90b 100644
--- a/tests/test_getg2ir.F90
+++ b/tests/test_getg2ir.F90
@@ -20,58 +20,75 @@ subroutine getg2ir(lugb, msk1, msk2, mnum, cbuf, nlen, nnum, nmess, iret)
      end subroutine getg2ir
   end interface
 
+  interface
+     subroutine getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, &
+          nnum, nmess, iret)
+       character(len = 1), pointer, dimension(:) :: cbuf
+       integer, intent(in) :: lugb, msk1, msk2, mnum, idxver
+       integer, intent(out) :: nlen, nnum, nmess, iret
+     end subroutine getg2i2r
+  end interface
   integer :: index_rec_len, b2s_message, b2s_lus, b2s_gds, b2s_pds, b2s_drs, b2s_bms, b2s_data
   integer :: total_bytes, grib_version, discipline, field_number
+  integer :: idxver, t
+
+  print *, 'Testing the getg2ir()/getg2i2r() subroutines.'
 
-  print *, 'Testing the getg2ir() subroutine - expect and ignore error messages during test...'
+  do t = 1, 2
+     ! Open a real GRIB2 file.
+     print *, 'Indexing a real GRIB2 file, trial ', t
+     call baopenr(lugb, "data/WW3_Regional_US_West_Coast_20220718_0000.grib2", iret)
+     if (iret .ne. 0) stop 100
 
-  ! Open a real GRIB2 file.
-  print *, 'Indexing a real GRIB2 file...'
-  call baopenr(lugb, "data/WW3_Regional_US_West_Coast_20220718_0000.grib2", iret)
-  if (iret .ne. 0) stop 100
+     msk1 = 1000
+     msk2 = 1000
+     mnum = 0
+     if (t .eq. 1) then
+        call getg2ir(lugb, msk1, msk2, mnum, cbuf, nlen, nnum, nmess, iret)
+     else
+        idxver = 1
+        call getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, nnum, nmess, iret)
+     endif
+     if (iret .ne. 0) stop 101
+     if (nlen .ne. 137600 .or. nnum .ne. 688 .or. nmess .ne. 688) stop 102
+     print *, 'nlen, nnum, nmess: ', nlen, nnum, nmess
 
-  msk1 = 1000
-  msk2 = 1000
-  mnum = 0
-  call getg2ir(lugb, msk1, msk2, mnum, cbuf, nlen, nnum, nmess, iret)
-  if (iret .ne. 0) stop 101
-  if (nlen .ne. 137600 .or. nnum .ne. 688 .or. nmess .ne. 688) stop 102
-  print *, 'nlen, nnum, nmess: ', nlen, nnum, nmess
-  
-  ! Break out the index record into component values.
-  call g2_gbytec(cbuf, index_rec_len, 0, 8 * 4)
-  if (index_rec_len .ne. 200) stop 105
-  call g2_gbytec(cbuf, b2s_message, 8 * 4, 8 * 4)
-  if (b2s_message .ne. 202) stop 106
-  call g2_gbytec(cbuf, b2s_lus, 8 * 8, 8 * 4)
-  if (b2s_lus .ne. 0) stop 107
-  call g2_gbytec(cbuf, b2s_gds, 8 * 12, 8 * 4)
-  if (b2s_gds .ne. 37) stop 108
-  call g2_gbytec(cbuf, b2s_pds, 8 * 16, 8 * 4)
-  if (b2s_pds .ne. 109) stop 109
-  call g2_gbytec(cbuf, b2s_drs, 8 * 20, 8 * 4)
-  if (b2s_drs .ne. 143) stop 110
-  call g2_gbytec(cbuf, b2s_bms, 8 * 24, 8 * 4)
-  if (b2s_bms .ne. 166) stop 111
-  call g2_gbytec(cbuf, b2s_data, 8 * 28, 8 * 4)
-  if (b2s_data .ne. 4721) stop 112
-  call g2_gbytec(cbuf, total_bytes, 8 * 32, 8 * 8)
-  if (total_bytes .ne. 11183) stop 113
-  call g2_gbytec(cbuf, grib_version, 8 * 40, 8 * 1)
-  if (grib_version .ne. 2) stop 113
-  call g2_gbytec(cbuf, discipline, 8 * 41, 8 * 1)
-  if (discipline .ne. 10) stop 113
-  call g2_gbytec(cbuf, field_number, 8 * 42, 8 * 2)
-  if (field_number .ne. 1) stop 113
-  print *, 'index_rec_len = ', index_rec_len, ' b2s_message = ', b2s_message
-  print *, 'b2s_lus, b2s_gds, b2s_pds, b2s_drs, b2s_bms, b2s_data: ', b2s_lus, b2s_gds, b2s_pds, b2s_drs, b2s_bms, b2s_data
-  print *, 'total_bytes, grib_version, discipline, field_number: ', total_bytes, grib_version, discipline, field_number
+     ! Break out the index record into component values.
+     call g2_gbytec(cbuf, index_rec_len, 0, 8 * 4)
+     if (index_rec_len .ne. 200) stop 105
+     call g2_gbytec(cbuf, b2s_message, 8 * 4, 8 * 4)
+     if (b2s_message .ne. 202) stop 106
+     call g2_gbytec(cbuf, b2s_lus, 8 * 8, 8 * 4)
+     if (b2s_lus .ne. 0) stop 107
+     call g2_gbytec(cbuf, b2s_gds, 8 * 12, 8 * 4)
+     if (b2s_gds .ne. 37) stop 108
+     call g2_gbytec(cbuf, b2s_pds, 8 * 16, 8 * 4)
+     if (b2s_pds .ne. 109) stop 109
+     call g2_gbytec(cbuf, b2s_drs, 8 * 20, 8 * 4)
+     if (b2s_drs .ne. 143) stop 110
+     call g2_gbytec(cbuf, b2s_bms, 8 * 24, 8 * 4)
+     if (b2s_bms .ne. 166) stop 111
+     call g2_gbytec(cbuf, b2s_data, 8 * 28, 8 * 4)
+     if (b2s_data .ne. 4721) stop 112
+     call g2_gbytec(cbuf, total_bytes, 8 * 32, 8 * 8)
+     if (total_bytes .ne. 11183) stop 113
+     call g2_gbytec(cbuf, grib_version, 8 * 40, 8 * 1)
+     if (grib_version .ne. 2) stop 113
+     call g2_gbytec(cbuf, discipline, 8 * 41, 8 * 1)
+     if (discipline .ne. 10) stop 113
+     call g2_gbytec(cbuf, field_number, 8 * 42, 8 * 2)
+     if (field_number .ne. 1) stop 113
+     print *, 'index_rec_len = ', index_rec_len, ' b2s_message = ', b2s_message
+     print *, 'b2s_lus, b2s_gds, b2s_pds, b2s_drs, b2s_bms, b2s_data: ', b2s_lus, b2s_gds, b2s_pds, b2s_drs, b2s_bms, b2s_data
+     print *, 'total_bytes, grib_version, discipline, field_number: ', total_bytes, grib_version, discipline, field_number
 
-  deallocate(cbuf)
-  
-  call baclose(lugb, iret)
-  if (iret .ne. 0) stop 199
+     deallocate(cbuf)
+     cbuf => null()
 
+     call baclose(lugb, iret)
+     if (iret .ne. 0) stop 199
+     print *, 'OK!'
+  end do
   print *, 'SUCCESS!...'
 
 end program test_getg2ir

From d5ad459e88b1cb2432f9f2df8de59f4a029a8575 Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Mon, 5 Feb 2024 06:42:57 -0700
Subject: [PATCH 10/12] more work on new index format

---
 src/g2index.F90        | 10 +++++++---
 tests/test_getg2ir.F90 | 11 ++++++++---
 2 files changed, 15 insertions(+), 6 deletions(-)

diff --git a/src/g2index.F90 b/src/g2index.F90
index ee388a42..dd05f553 100644
--- a/src/g2index.F90
+++ b/src/g2index.F90
@@ -322,13 +322,16 @@ end subroutine getg2ir
 !> - 3 Error deallocating memory.
 !>
 !> @author Mark Iredell, Edward Hartnett @date Feb 4, 2024
-subroutine getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, &
+subroutine getg2i2r(lugb, msk18, msk28, mnum, idxver, cbuf, nlen, &
      nnum, nmess, iret)
   use re_alloc              ! needed for subroutine realloc
   implicit none
 
   character(len = 1), pointer, dimension(:) :: cbuf
-  integer, intent(in) :: lugb, msk1, msk2, mnum, idxver
+  integer, intent(in) :: lugb
+  integer (kind = 8), intent(in) :: msk18, msk28
+  integer :: msk1, msk2
+  integer, intent(in) :: mnum, idxver
   integer, intent(out) :: nlen, nnum, nmess, iret
   character(len = 1), pointer, dimension(:) :: cbuftmp
   integer :: nbytes, newsize, next, numfld, m, mbuf, lskip, lgrib
@@ -343,7 +346,8 @@ subroutine ixgb2(lugb, lskip, lgrib, cbuf, numfld, mlen, iret)
      end subroutine ixgb2
   end interface
 
-  print *, idxver
+  msk1 = msk18
+  msk2 = msk28
 
   ! Initialize.
   iret = 0
diff --git a/tests/test_getg2ir.F90 b/tests/test_getg2ir.F90
index 1323d90b..409cfe03 100644
--- a/tests/test_getg2ir.F90
+++ b/tests/test_getg2ir.F90
@@ -10,6 +10,7 @@ program test_getg2ir
   integer :: lugb = 3
   character(len=1), pointer, dimension(:) :: cbuf(:)
   integer :: msk1, msk2, mnum
+  integer (kind = 8) :: msk18, msk28
   integer :: nlen, nnum, nmess, iret
 
   interface
@@ -21,10 +22,12 @@ end subroutine getg2ir
   end interface
 
   interface
-     subroutine getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, &
+     subroutine getg2i2r(lugb, msk18, msk28, mnum, idxver, cbuf, nlen, &
           nnum, nmess, iret)
        character(len = 1), pointer, dimension(:) :: cbuf
-       integer, intent(in) :: lugb, msk1, msk2, mnum, idxver
+       integer, intent(in) :: lugb
+       integer (kind = 8), intent(in) :: msk18, msk28
+       integer, intent(in) :: mnum, idxver
        integer, intent(out) :: nlen, nnum, nmess, iret
      end subroutine getg2i2r
   end interface
@@ -42,12 +45,14 @@ end subroutine getg2i2r
 
      msk1 = 1000
      msk2 = 1000
+     msk18 = 1000
+     msk28 = 1000
      mnum = 0
      if (t .eq. 1) then
         call getg2ir(lugb, msk1, msk2, mnum, cbuf, nlen, nnum, nmess, iret)
      else
         idxver = 1
-        call getg2i2r(lugb, msk1, msk2, mnum, idxver, cbuf, nlen, nnum, nmess, iret)
+        call getg2i2r(lugb, msk18, msk28, mnum, idxver, cbuf, nlen, nnum, nmess, iret)
      endif
      if (iret .ne. 0) stop 101
      if (nlen .ne. 137600 .or. nnum .ne. 688 .or. nmess .ne. 688) stop 102

From f601c55372daa4d1ccc40ebec5d5cb94973d0f01 Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Mon, 5 Feb 2024 06:55:51 -0700
Subject: [PATCH 11/12] further index progress

---
 src/g2index.F90 | 87 ++++++++++++++++++++++++++++++++++++++++++++++---
 1 file changed, 83 insertions(+), 4 deletions(-)

diff --git a/src/g2index.F90 b/src/g2index.F90
index dd05f553..970ca292 100644
--- a/src/g2index.F90
+++ b/src/g2index.F90
@@ -733,11 +733,89 @@ END SUBROUTINE GETGB2S
 !> - 5 Unidentified GRIB section encountered.
 !>
 !> @author Mark Iredell @date 1995-10-31
-SUBROUTINE IXGB2(LUGB, LSKIP, LGRIB, CBUF, NUMFLD, MLEN, IRET)
-  USE RE_ALLOC              ! NEEDED FOR SUBROUTINE REALLOC
+subroutine ixgb2(lugb, lskip, lgrib, cbuf, numfld, mlen, iret)
+  implicit none
+  integer :: lugb, lskip, lgrib
+  character(len = 1), pointer, dimension(:) :: cbuf
+  integer :: numfld, mlen, iret
+  integer (kind = 8) :: lskip8
+
+  interface
+     subroutine ix2gb2(lugb, lskip8, idxver, lgrib, cbuf, numfld, mlen, iret)
+       integer :: lugb
+       integer (kind = 8) :: lskip8
+       integer :: idxver, lgrib
+       character(len = 1), pointer, dimension(:) :: cbuf
+       integer :: numfld, mlen, iret
+     end subroutine ix2gb2
+  end interface
+
+  lskip8 = lskip
+  call ix2gb2(lugb, lskip8, 1, lgrib, cbuf, numfld, mlen, iret)
+end SUBROUTINE IXGB2
+
+!> Generate an index record for each field in a GRIB2 message. The index
+!> records are written to index buffer pointed to by cbuf. All integers
+!> in the index are in big-endian format.
+!>
+!> This subroutine is called by getg2ir(), which packages the index
+!> records into an index file.
+!>
+!> The index buffer returned contains index records with the
+!> format:
+!> - byte 001 - 004 length of index record
+!> - byte 005 - 008 bytes to skip in data file before GRIB message
+!> - byte 009 - 012 bytes to skip in message before lus (local use) set = 0, if no local section.
+!> - byte 013 - 016 bytes to skip in message before gds
+!> - byte 017 - 020 bytes to skip in message before pds
+!> - byte 021 - 024 bytes to skip in message before drs
+!> - byte 025 - 028 bytes to skip in message before bms
+!> - byte 029 - 032 bytes to skip in message before data section
+!> - byte 033 - 040 bytes total in the message
+!> - byte 041 - 041 GRIB version number (2)
+!> - byte 042 - 042 message discipline
+!> - byte 043 - 044 field number within GRIB2 message
+!> - byte 045 -  ii identification section (ids)
+!> - byte ii + 1-  jj grid definition section (gds)
+!> - byte jj + 1-  kk product definition section (pds)
+!> - byte kk + 1-  ll the data representation section (drs)
+!> - byte ll + 1-ll + 6 first 6 bytes of the bit map section (bms)
+!>
+!> @param lugb Unit of the unblocked GRIB file. Must
+!> be opened by [baopen() or baopenr()]
+!> (https://noaa-emc.github.io/NCEPLIBS-bacio/).
+!> @param lskip8 Number of bytes to skip before GRIB message.
+!> @param idxver Index version, 1 for legacy, 2 for GRIB2 files > 2 GB.
+!> @param lgrib Number of bytes in GRIB message. When subroutine is
+!> called, this must be set to the size of the cbuf buffer.
+!> @param cbuf Pointer to a buffer that will get the index
+!> records. If any memory is associated with cbuf when this subroutine
+!> is called, cbuf will be nullified in the subroutine. Initially cbuf
+!> will get an allocation of 5000 bytes. realloc() will be used to
+!> increase the size if necessary. Users must free memory that cbuf
+!> points to when cbuf is no longer needed.
+!> @param numfld Number of index records created.
+!> @param mlen Total length of all index records.
+!> @param iret Return code
+!> - 0 No error
+!> - 1 Not enough memory available to hold full index buffer.
+!> - 2 I/O error in read.
+!> - 3 GRIB message is not edition 2.
+!> - 4 Not enough memory to allocate extent to index buffer.
+!> - 5 Unidentified GRIB section encountered.
+!>
+!> @author Mark Iredell @date 1995-10-31
+subroutine ix2gb2(lugb, lskip8, idxver, lgrib, cbuf, numfld, mlen, iret)
+  use re_alloc              ! needed for subroutine realloc
   implicit none
 
+  integer :: lugb
+  integer (kind = 8) :: lskip8
+  integer :: idxver, lgrib
   CHARACTER(LEN = 1), POINTER, DIMENSION(:) :: CBUF
+  integer :: numfld, mlen, iret
+  integer :: lskip
+  
   CHARACTER CVER, CDISC
   CHARACTER(LEN = 4) :: CTEMP
   INTEGER LOCLUS, LOCGDS, LENGDS, LOCBMS
@@ -745,7 +823,7 @@ SUBROUTINE IXGB2(LUGB, LSKIP, LGRIB, CBUF, NUMFLD, MLEN, IRET)
   integer :: linmax, ixskp
   integer :: mxspd, mxskp, mxsgd, mxsdr, mxsbm, mxlus
   integer :: mxlen, mxds, mxfld, mxbms
-  integer :: init, ixlus, lugb, lskip, lgrib, numfld, mlen, iret
+  integer :: init, ixlus
   integer :: ixsgd, ibread, ibskip, ilndrs, ilnpds, istat, ixds
   integer :: ixspd, ixfld, ixids, ixlen, ixsbm, ixsdr
   integer :: lbread, lensec, lensec1
@@ -757,6 +835,7 @@ SUBROUTINE IXGB2(LUGB, LSKIP, LGRIB, CBUF, NUMFLD, MLEN, IRET)
   CHARACTER CBREAD(LINMAX), CINDEX(LINMAX)
   CHARACTER CIDS(LINMAX), CGDS(LINMAX)
 
+  lskip = lskip8
   LOCLUS = 0
   IRET = 0
   MLEN = 0
@@ -875,7 +954,7 @@ SUBROUTINE IXGB2(LUGB, LSKIP, LGRIB, CBUF, NUMFLD, MLEN, IRET)
      ENDIF
      IBSKIP = IBSKIP + LENSEC
   ENDDO
-END SUBROUTINE IXGB2
+end subroutine ix2gb2
 
 !> Free all memory associated with the library.
 !>

From 9104baeaf522150a2ceb1f99bc6ff86525b6fa80 Mon Sep 17 00:00:00 2001
From: Edward Hartnett <edward.hartnett@noaa.gov>
Date: Mon, 5 Feb 2024 06:57:16 -0700
Subject: [PATCH 12/12] fixed documentation

---
 src/g2index.F90 | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/g2index.F90 b/src/g2index.F90
index 970ca292..5ae1bcd7 100644
--- a/src/g2index.F90
+++ b/src/g2index.F90
@@ -301,8 +301,8 @@ end subroutine getg2ir
 !> @param[in] lugb Unit of the unblocked GRIB file. Must
 !> be opened by [baopen() or baopenr()]
 !> (https://noaa-emc.github.io/NCEPLIBS-bacio/).
-!> @param[in] msk1 Number of bytes to search for first message.
-!> @param[in] msk2 Number of bytes to search for other messages.
+!> @param[in] msk18 Number of bytes to search for first message.
+!> @param[in] msk28 Number of bytes to search for other messages.
 !> @param[in] mnum Number of GRIB messages to skip (usually 0).
 !> @param[in] idxver Index version, 1 for legacy, 2 for files > 2 GB.
 !> @param[out] cbuf Pointer to a buffer that will get the index