diff --git a/.github/workflows/developer.yml b/.github/workflows/developer.yml
index fa9dd0d5..6755a5f8 100644
--- a/.github/workflows/developer.yml
+++ b/.github/workflows/developer.yml
@@ -110,7 +110,7 @@ jobs:
         export CFLAGS='-Wall -g -fprofile-abs-path -fprofile-arcs -ftest-coverage -O0 -I/home/runner/g2c/include'
         export FCFLAGS='-Wall -g -fprofile-abs-path -fprofile-arcs -ftest-coverage -O0'
         export FFLAGS='-Wall -g -fprofile-abs-path -fprofile-arcs -ftest-coverage -O0'
-        cmake .. -DENABLE_DOCS=ON -DFTP_TEST_FILES=ON -DCMAKE_PREFIX_PATH="~/ip;~/jasper;~/g2c" -DTEST_FILE_DIR=/home/runner/data -DUSE_NETCDF4=ON -DUSE_AEC=ON -DUSE_IPOLATES=ON -DUSE_JASPER=ON
+        cmake .. -DENABLE_DOCS=ON -DFTP_TEST_FILES=ON -DCMAKE_PREFIX_PATH="~/ip;~/jasper;~/g2c" -DTEST_FILE_DIR=/home/runner/data -DUSE_NETCDF4=ON -DUSE_AEC=ON -DUSE_IPOLATES=ON -DUSE_JASPER=ON -DMAKE_FTN_API=ON
         make VERBOSE=1
         ctest --verbose --output-on-failure --rerun-failed
         gcovr --root .. -v  --html-details --exclude ../tests --exclude CMakeFiles --print-summary -o test-coverage.html &> /dev/null
diff --git a/CMakeLists.txt b/CMakeLists.txt
index ac62e561..5180776b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -35,8 +35,13 @@ option(FTP_EXTRA_TEST_FILES "Fetch even more large files from FTP and test them.
 option(MAKE_FTN_API "add ftn api?" off)
 option(DISABLE_STAT "disable posix feature" off)
 set(BUILD_COMMENTS "stock build")
+
 option(BUILD_LIB "Build wgrib2 library?" on)
-option(BUILD_SHARED_LIB "Build shared library?" off)
+# if BUILD_LIB, then code is compiled as relocatable
+option(BUILD_SHARED_LIB "Build shared library?" on)
+# To create libwgrib2.so for python, you have to build with BUILD_SHARED_LIB off
+# and manually create libwgrib2.so from the needed *.a files
+
 option(BUILD_WGRIB "Build wgrib code?" off)
 
 if (MAKE_FTN_API OR USE_IPOLATES)
@@ -84,6 +89,10 @@ if(USE_G2CLIB)
   endif()
 endif()
 
+if (BUILD_SHARED_LIB AND NOT BUILD_LIB)
+   message(FATAL_ERROR "BUILD_SHARED_LIB is on but BUILD_LIB is off")
+endif()
+
 # If user wants to use NCEPLIBS-ip, find it and the sp library.
 message(STATUS "Checking if the user want to use NCEPLIBS-ip...")
 if(USE_IPOLATES)
diff --git a/tests/CMakeLists.txt b/tests/CMakeLists.txt
index d14fced4..e8a0ee3b 100644
--- a/tests/CMakeLists.txt
+++ b/tests/CMakeLists.txt
@@ -166,6 +166,17 @@ if (USE_JASPER OR USE_OPENJPEG)
   copy_test_data(ref_jpeg2simple.txt)
 endif()
 
+if (MAKE_FTN_API)
+  shell_test(test_ftn_api)
+endif()
+if (BUILD_LIB)
+  shell_test(test_lib)
+endif()
+if (BUILD_SHARED_LIB)
+  shell_test(test_shared_lib)
+endif()
+
+
 if (FTP_TEST_FILES)
   copy_test_data(ref_WW3_Regional_US_West_Coast_20220718_0000.grib2.inv)
   copy_test_data(ref_merge_fcst.aqm.t12z.max_8hr_o3.227.grib2.txt)
diff --git a/tests/test_ftn_api.sh b/tests/test_ftn_api.sh
new file mode 100755
index 00000000..fe8b079b
--- /dev/null
+++ b/tests/test_ftn_api.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+#
+# script to see if ftn_api compiled
+#
+
+echo "see if ftn_api compiled"
+set -xe
+
+if [ ! -f ../wgrib2/ftn_api/include/wgrib2api.mod ] ; then
+   echo "failed: did not find wgrib2api.mod"
+   exit 1
+fi
+
+echo "*** SUCCESS!"
+exit 0
diff --git a/tests/test_lib.sh b/tests/test_lib.sh
new file mode 100755
index 00000000..a7c46f1e
--- /dev/null
+++ b/tests/test_lib.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+#
+# script to see if shared lib was made
+#
+
+echo "see if shared library made"
+set -xe
+
+if [ ! -f ../wgrib2/libwgrib2.so -a ! -f ../wgrib2/libwgrib2.a ] ; then
+   echo "failed: did not find libwgrib2"
+   exit 1
+fi
+
+echo "*** SUCCESS!"
+exit 0
diff --git a/tests/test_shared_lib.sh b/tests/test_shared_lib.sh
new file mode 100755
index 00000000..fd96f986
--- /dev/null
+++ b/tests/test_shared_lib.sh
@@ -0,0 +1,15 @@
+#!/bin/sh
+#
+# script to see if shared lib was made
+#
+
+echo "see if shared library made"
+set -xe
+
+if [ ! -f ../wgrib2/libwgrib2.so ] ; then
+   echo "failed: did not find libwgrib2.so"
+   exit 1
+fi
+
+echo "*** SUCCESS!"
+exit 0
diff --git a/wgrib2/CMakeLists.txt b/wgrib2/CMakeLists.txt
index 2bea5cd7..ec750d72 100644
--- a/wgrib2/CMakeLists.txt
+++ b/wgrib2/CMakeLists.txt
@@ -2,6 +2,19 @@
 # subdirectory.
 #
 # Kyle Gerheiser, Edward Hartnett, Wesley Ebisuzaki
+#
+# if BUILD_SHARED_LIB
+#    ftn_api    -> shared library, interface to fortran
+#    wgrib2_lib -> shared  (includes gctpc)
+#
+# if !BUILD_SHARED_LIB
+#    ftn_api    -> static library, interface to fortran
+#    wgrib2_lib -> static library includeing gctpc
+#
+# note: in wgrib2 v3.1.3 or earlier, all the libraries
+#  incuding aec, jasper, etc were included with the wgrib2 library
+#  in github version, it is different.
+
 
 # sets lib_src
 set(lib_src AAIG.c AAIGlong.c addtime.c aec_pk.c Aerosol.c Alarm.c
@@ -44,14 +57,16 @@ Type_reftime.c UDF.c Undefine.c units.c Unix_time.c Unmerge_fcst.c
 unpk_0.c unpk.c unpk_complex.c unpk_run_length.c update_sec3.c
 update_sec4.c v1_v2_if.c VerfTime.c Warn_old_g2lib.c Waves.c
 wgrib2_api.c wgrib2.c Wind_dir.c Wind_speed.c Wind_uv.c Write_sec.c
-Wrt_grib.c wrtieee.c wxtext.c)
+Wrt_grib.c wrtieee.c wxtext.c
+)
+
+include_directories(gctpc/source/include)
+add_subdirectory(gctpc)
 
 if(MAKE_FTN_API)
   add_subdirectory(ftn_api)
 endif()
 
-add_subdirectory(gctpc)
-
 # make this an object lib so we can re-use most of object files
 # The only files that differ are ${callable_src} which are compiled
 # with -DCALLABLE_WGRIB2
@@ -67,25 +82,27 @@ configure_file (
 
 if(BUILD_LIB)
 
-  # with -DCALLABLE_WGRIB2 for the lib
   if(BUILD_SHARED_LIB)
-    add_library(wgrib2_lib SHARED ${lib_src} $<TARGET_OBJECTS:gctpc> ${callable_src})
+    add_library(wgrib2_lib SHARED ${lib_src} )
+    set_property(TARGET wgrib2_lib PROPERTY POSITION_INDEPENDENT_CODE ON)
   else()
-    add_library(wgrib2_lib STATIC ${lib_src} $<TARGET_OBJECTS:gctpc> ${callable_src})
+    add_library(wgrib2_lib STATIC ${lib_src} $<TARGET_OBJECTS:gctpc> )
+#    add_library(wgrib2_lib STATIC ${lib_src} )
+    set_property(TARGET wgrib2_lib PROPERTY POSITION_INDEPENDENT_CODE ON)
   endif()
 
   # library and executable have same name (wgrib2) but different target names
   set_target_properties(wgrib2_lib PROPERTIES OUTPUT_NAME wgrib2)
-  target_compile_definitions(wgrib2_lib PRIVATE CALLABLE_WGRIB2)
+  # target_compile_definitions(wgrib2_lib PRIVATE CALLABLE_WGRIB2)
 endif()
 
 
-# without -DCALLABLE_WGRIB2 for the executable
-add_executable(wgrib2_exe ${callable_src})
+add_executable(wgrib2_exe wgrib2_main.c)
 set_target_properties(wgrib2_exe PROPERTIES OUTPUT_NAME wgrib2)
 
 if(USE_NETCDF)
   target_link_libraries(obj_lib PUBLIC NetCDF::NetCDF_C)
+  target_link_libraries(wgrib2_exe PUBLIC NetCDF::NetCDF_C)
 endif()
 
 if(USE_PNG)
@@ -98,6 +115,7 @@ endif()
 
 if(USE_IPOLATES)
   target_link_libraries(obj_lib PUBLIC ip::ip_d)
+  target_link_libraries(wgrib2_exe PUBLIC ip::ip_d)
 
   # Link to the Fortran runtime library for each compiler if using ip2.
   # The wgrib2 exectuable is created using the C compiler and
@@ -110,10 +128,10 @@ if(USE_IPOLATES)
   
 endif()
 
-target_link_libraries(obj_lib PUBLIC gctpc -lm)
+## target_link_libraries(obj_lib PUBLIC gctpc -lm)
 
-# Link to gctpc directly because oobject libraries do not link transitively
-target_link_libraries(wgrib2_exe PRIVATE gctpc)
+# Link to gctpc directly because object libraries do not link transitively
+target_link_libraries(wgrib2_exe PRIVATE gctpc -lm)
 
 if(USE_AEC)
   target_link_libraries(wgrib2_exe PRIVATE ${LIBAEC_LIBRARIES})
@@ -130,10 +148,11 @@ if(USE_OPENJPEG)
 endif()
 
 target_link_libraries(wgrib2_exe PRIVATE obj_lib)
+# target_link_libraries(wgrib2_exe PRIVATE wgrib2_lib)
 
 if(BUILD_LIB)
   set(headers wgrib2_api.h wgrib2.h ${CMAKE_BINARY_DIR}/wgrib2/wgrib2_meta.h)
-  target_link_libraries(wgrib2_lib PUBLIC gctpc)
+##   target_link_libraries(wgrib2_lib PUBLIC gctpc)
   set_target_properties(wgrib2_lib PROPERTIES PUBLIC_HEADER "${headers}")
   target_compile_definitions(wgrib2_lib PUBLIC ${definitions_list})
   
@@ -156,6 +175,3 @@ install(
   ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR})
 
 
-
-
-
diff --git a/wgrib2/fatal_error.c b/wgrib2/fatal_error.c
index 7b94a430..2c6d949c 100644
--- a/wgrib2/fatal_error.c
+++ b/wgrib2/fatal_error.c
@@ -1,9 +1,9 @@
 #include <stdio.h>
 #include <stdarg.h>
 #include <stdlib.h>
-#ifdef CALLABLE_WGRIB2
+
 #include <setjmp.h>
-#endif
+
 #include "wgrib2.h"
 
 /*
@@ -17,9 +17,9 @@
  *         fprintf(ARGS)
  *         do_fatal_error_processing
  */
-#ifdef CALLABLE_WGRIB2
+
 extern jmp_buf fatal_err;
-#endif
+
 
 
 void fatal_error(const char *fmt, ...)
@@ -32,9 +32,9 @@ void fatal_error(const char *fmt, ...)
     va_end(arg);
 
     err_bin(1); err_string(1);
-#ifdef CALLABLE_WGRIB2
+
     longjmp(fatal_err,1);
-#endif
+
     exit(8);
     return;
 }
diff --git a/wgrib2/ftn_api/CMakeLists.txt b/wgrib2/ftn_api/CMakeLists.txt
index 7a8a8c3a..81a77dbc 100644
--- a/wgrib2/ftn_api/CMakeLists.txt
+++ b/wgrib2/ftn_api/CMakeLists.txt
@@ -13,21 +13,26 @@ set(c_src
   fort_wgrib2.c
   )
 
-add_library(wgrib2_api ${fortran_src} ${c_src})
+if (BUILD_SHARED_LIB)
+   add_library(wgrib2_ftn_api SHARED ${fortran_src} ${c_src})
+else()
+   add_library(wgrib2_ftn_api STATIC ${fortran_src} ${c_src})
+   set_property(TARGET wgrib2_ftn_api PROPERTY POSITION_INDEPENDENT_CODE ON)
+endif()
 
 set(module_dir "${CMAKE_CURRENT_BINARY_DIR}/${CMAKE_INSTALL_INCLUDEDIR}")
-set_target_properties(wgrib2_api PROPERTIES Fortran_MODULE_DIRECTORY ${module_dir})
+set_target_properties(wgrib2_ftn_api PROPERTIES Fortran_MODULE_DIRECTORY ${module_dir})
 
-target_include_directories(wgrib2_api
+target_include_directories(wgrib2_ftn_api
     PUBLIC $<BUILD_INTERFACE:${module_dir}>
     $<INSTALL_INTERFACE:${CMAKE_INSTALL_PREFIX}/${CMAKE_INSTALL_INCLUDEDIR}>)
 
-target_link_libraries(wgrib2_api PUBLIC wgrib2_lib)  
+target_link_libraries(wgrib2_ftn_api PUBLIC wgrib2_lib)  
 
 install(DIRECTORY ${module_dir} DESTINATION ${CMAKE_INSTALL_PREFIX})
 
 install(
-  TARGETS wgrib2_api
+  TARGETS wgrib2_ftn_api
   EXPORT wgrib2_exports
   RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
   LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
diff --git a/wgrib2/gctpc/source/CMakeLists.txt b/wgrib2/gctpc/source/CMakeLists.txt
index a077a587..8bf84a5b 100644
--- a/wgrib2/gctpc/source/CMakeLists.txt
+++ b/wgrib2/gctpc/source/CMakeLists.txt
@@ -1,3 +1,7 @@
+# note: this CMakelist.txt is for building the gctpc library
+#   wgrib2 now includes the library into the source compile
+#   so the wgrib2 library now include gctpc.  This makes it
+#   easier for users who want to use the wgrib2 library.
 
 set(src
   alberfor.c
@@ -76,7 +80,13 @@ set(src
   wviiinv.c
   )
 
+# if want shared library, had to make separate library
+# otherwise include gctpc in libwgrib2.a
+
 add_library(gctpc OBJECT ${src})
+if (BUILD_LIB)
+  set_property(TARGET gctpc PROPERTY POSITION_INDEPENDENT_CODE ON)
+endif()
 
 target_include_directories(gctpc PUBLIC
   $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/include>
diff --git a/wgrib2/wgrib2.c b/wgrib2/wgrib2.c
index 806a5f26..b948ba35 100644
--- a/wgrib2/wgrib2.c
+++ b/wgrib2/wgrib2.c
@@ -1,4 +1,7 @@
-/* wgrib2 main module:  public domain 2005 w. ebisuzaki
+/* wgrib2:  public domain 2005 w. ebisuzaki
+ *          originally the main of the wgrib2 utility
+ *          later became main or routine depending on CALLABLE_WGRIB2
+ *          finally wgrib2 utility became a wrapper that calls the wgrib2 routine
  *
  * CHECK code is now duplicated
  *  if (decode) -- check before decoding
@@ -17,10 +20,9 @@
 #include <sys/stat.h>
 #include <errno.h>
 
-#ifdef CALLABLE_WGRIB2
+
 #include <setjmp.h>
 jmp_buf fatal_err;
-#endif
 
 #include "grb2.h"
 #include "wgrib2.h"
@@ -116,17 +118,9 @@ int version_if;		/* 0-old stype 1-modern if */
  * simple wgrib for GRIB2 files
  *
  */
-#ifndef CALLABLE_WGRIB2
-
-int main(int argc, const char **argv) {
-
-#else
 
 int wgrib2(int argc, const char **argv) {
 
-#endif
-
-
 //WNE    FILE *in;
     struct seq_file in_file;
     unsigned char *msg, *sec[10];	/* sec[9] = last valid bitmap */
@@ -176,9 +170,9 @@ int wgrib2(int argc, const char **argv) {
     data = NULL;
 //    ddata = NULL;
 
-#ifdef CALLABLE_WGRIB2
+
     if (setjmp(fatal_err)) {
-	fprintf(stderr,"*** arg list to wgrib2:");
+	fprintf(stderr,"*** arg list to wgrib2(..):");
 	for (i=0; i < argc; i++) {
 	    fprintf(stderr," %s", argv[i]);
 	}
@@ -186,9 +180,9 @@ int wgrib2(int argc, const char **argv) {
 	if (ndata && data != NULL) free(data);
 	ndata=0;
 	if (in_file.file_type != NOT_OPEN) fclose_file(&in_file);
-	return 1;
+	return 8;
     }
-#endif
+
 
     /* no arguments .. help screen */
     if (argc == 1) {
@@ -565,7 +559,7 @@ int wgrib2(int argc, const char **argv) {
 		if (GDS_max_size) free(old_gds);
 		GDS_max_size = i + 100;		/* add 100 just to avoid excessive memory allocations */
     		if ((old_gds = (unsigned char *) malloc(GDS_max_size) ) == NULL) {
-			fatal_error("memory allocation problem old_gds in wgrib2.main for %s",in_file.filename);
+			fatal_error("memory allocation problem old_gds in wgrib2(..) for %s",in_file.filename);
 		}
 	    }
 #ifdef IS_OPENMP_4_0
@@ -692,7 +686,7 @@ int wgrib2(int argc, const char **argv) {
                     data = (float *) malloc(sizeof(float) * (size_t) ndata);
                     if (data == NULL) {
 			ndata = 0;
-			fatal_error("main: memory allocation failed data","");
+			fatal_error("wgrib2(..): memory allocation failed data","");
 		    }
 		}
                 else { data = NULL; }
diff --git a/wgrib2/wgrib2_api.c b/wgrib2/wgrib2_api.c
index d99e866d..3f081f00 100644
--- a/wgrib2/wgrib2_api.c
+++ b/wgrib2/wgrib2_api.c
@@ -3,7 +3,6 @@
 #include <stdarg.h>
 #include "wgrib2.h"
 
-#ifdef CALLABLE_WGRIB2 
 
 /* 
    sort of like the command line version of wgrib2
@@ -43,4 +42,3 @@ int wgrib2a(char *arg1, ...) {
     return i;
 }
 
-#endif
diff --git a/wgrib2/wgrib2_main.c b/wgrib2/wgrib2_main.c
new file mode 100644
index 00000000..449ce054
--- /dev/null
+++ b/wgrib2/wgrib2_main.c
@@ -0,0 +1,27 @@
+/* wgrib2 main module:  public domain 2024 w. ebisuzaki
+ *
+ * ancient:  wgrib2.c was the main for the wgrib2 utility.  There was no wgrib2 library, and
+ *           no call to the wgrib2(..).
+ *
+ * old:      A user wanted to call wgrib2 from a C program.  He converted wgrib2.c to be either a main(..)
+ *           or a routine wgrib2(..) depending on a flag (CALLABLE_WGRIB2).  There were two builds,
+ *           one for the utility and a second for the library.
+ *
+ * new:      move to github
+ *           Reimplement the old idea to make the wgrib2 utility a call to wgrib2(..).
+ *           This involves removing all references to CALLABLE_WGRIB2
+ *           This was tested in a pre-github version but never implemented because it provided no reward
+ *           With github, the build system is being rebuilt from Kyle's version.  Rather than the two
+ *           builds, make it a single build with the wgrib2 utility calling wgrib2(..)
+
+ *
+ * 8/2024    the main for the wgrib2 utility is moved from wgrib2.c to wgrib2_main.c
+ */
+
+#include <stdio.h>
+#include "wgrib2_api.h"
+
+
+int main(int argc, const char **argv) {
+   return wgrib2(argc, argv);
+}