I wrote unit tests for all the Fortran interface commands in this pull request

unittest/fortran/test_fortran_properties.f90

@@ -0,0 +1,52 @@
+FUNCTION f_lammps_version () BIND(C)
+   USE, INTRINSIC :: ISO_C_BINDING, ONLY : C_int
+   USE liblammps
+   USE keepcmds, ONLY : lmp
+   IMPLICIT NONE
+   INTEGER (C_int) :: f_lammps_version
+
+   f_lammps_version = lmp%version()
+END FUNCTION f_lammps_version
+
+SUBROUTINE f_lammps_memory_usage (meminfo) BIND(C)
+   USE, INTRINSIC :: ISO_C_BINDING, ONLY : C_double
+   USE liblammps
+   USE keepcmds, ONLY : lmp
+   IMPLICIT NONE
+   REAL (C_double), DIMENSION(3), INTENT(OUT) :: meminfo
+
+   CALL lmp%memory_usage(meminfo)
+END SUBROUTINE f_lammps_memory_usage
+
+FUNCTION f_lammps_get_mpi_comm () BIND(C)
+   USE, INTRINSIC :: ISO_C_BINDING, ONLY : C_int
+   USE liblammps
+   USE keepcmds, ONLY : lmp
+   IMPLICIT NONE
+   INTEGER (C_int) :: f_lammps_get_mpi_comm
+
+   f_lammps_get_mpi_comm = lmp%get_mpi_comm()
+END FUNCTION f_lammps_get_mpi_comm
+
+FUNCTION f_lammps_extract_setting (Cstr) BIND(C)
+   USE, INTRINSIC :: ISO_C_BINDING, ONLY : C_int, C_char
+   USE keepcmds, ONLY : lmp
+   USE LIBLAMMPS
+   IMPLICIT NONE
+   INTEGER (C_int) :: f_lammps_extract_setting
+   CHARACTER (KIND=C_char, LEN=1), DIMENSION(*), INTENT(IN) :: Cstr
+   INTEGER :: strlen, i
+   CHARACTER (LEN=:), ALLOCATABLE :: Fstr
+
+   i = 1
+   DO WHILE (Cstr(i) /= ACHAR(0))
+      i = i + 1
+   END DO
+   strlen = i
+   allocate ( CHARACTER(LEN=strlen) :: Fstr)
+   FORALL (i=1:strlen)
+      Fstr(i:i) = Cstr(i)
+   END FORALL
+   f_lammps_extract_setting = lmp%extract_setting(Fstr)
+   deallocate (Fstr)
+END FUNCTION f_lammps_extract_setting