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			442 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Fortran
		
	
	
	
	
	
			
		
		
	
	
			442 lines
		
	
	
		
			16 KiB
		
	
	
	
		
			Fortran
		
	
	
	
	
	
!     FILE: c_interface_module.f90
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!     PURPOSE: Supplement ISO-C-Binding to provide type aliases and interfaces
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!     to common ISO-C string functions to aid working with strings.
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!     AUTHOR: Joseph M. Krahn
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!     STATUS: Still in development. Reasonably complete, but somewhat limited testing.
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!
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!     The idea is to provide type aliases for all ISO-C types, so that the
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!     Fortran interface code more explicitly defines the actual C interface.
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!     This should be updated to support F2008 variable-length allocatable
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!     strings.
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!
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!     Entity names all have the "C_" prefix, as with ISO-C-Binding, with a
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!     few exceptions.
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!
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!     Sourced from: http://fortranwiki.org/fortran/show/c_interface_module
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!
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!     One FORALL statement reverted to a DO loop to avoid a gfortran 4.9.2 ICE
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!
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module C_interface_module
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  use, intrinsic :: ISO_C_Binding, &
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                                !     C type aliases for pointer derived types:
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       C_ptr => C_ptr , &
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       C_char_ptr => C_ptr, &
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       C_const_char_ptr => C_ptr, &
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       C_void_ptr => C_ptr, &
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       C_const_void_ptr => C_ptr
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  implicit none
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  public
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  !----------------------------------------------------------------------------
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  !     C type aliases for intrinsic type KIND parameters:
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  !     NOTE: a C enum may not always be a standard C int
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  integer, parameter :: C_enum = C_int
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  !     Defining off_t is difficult, because it may depend on "LARGEFILE" selection.
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  !     integer, parameter :: C_off_t = ??
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  !     C string terminator alais using the 3-letter ASCII name.
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  !     The C_ prefix is not used because it is just an ASCII character.
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  character(len=1,kind=C_char), parameter :: NUL = C_NULL_char
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  !     NOTE: In C, "char" is distinct from "signed char", unlike integers.
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  !     The plain "char" type is specific for text/string values, whereas
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  !     "signed char" should indicate 1-byte integer data.
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  !
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  !     Most ISO-C systems have wide chars "wchar_t", but Fortran compilers
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  !     have limited support for different character kinds. UTF encoding
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  !     adds more complexity. This should be updated as Fortran compilers
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  !     include support for more character types.
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  !
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  !     Fortran does not (yet) support unsigned types.
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  integer, parameter :: &
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       C_unsigned = C_int, &
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       C_unsigned_short = C_short, &
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       C_unsigned_long = C_long, &
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       C_unsigned_long_long = C_long_long, &
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       C_unsigned_char = C_signed_char, &
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       C_ssize_t = C_size_t, &
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       C_uint8_t = C_int8_t, &
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       C_uint16_t = C_int16_t, &
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       C_uint32_t = C_int32_t, &
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       C_uint64_t = C_int64_t, &
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       C_uint_least8_t = C_int_least8_t, &
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       C_uint_least16_t = C_int_least16_t, &
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       C_uint_least32_t = C_int_least32_t, &
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       C_uint_least64_t = C_int_least64_t, &
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       C_uint_fast8_t = C_int_fast8_t, &
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       C_uint_fast16_t = C_int_fast16_t, &
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       C_uint_fast32_t = C_int_fast32_t, &
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       C_uint_fast64_t = C_int_fast64_t, &
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       C_uintmax_t = C_intmax_t
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  !     Note: ptrdiff_t cannot be reliably defined from other types.
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  !     When practical, it is larger than a pointer because it benefits
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  !     from the full unsigned range in both positive and negative directions.
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  !     Integer versions including 'int', where the 'int' is optional:
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  integer, parameter :: &
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       C_short_int = C_short, &
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       C_long_int = C_long, &
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       C_long_long_int = C_long_long, &
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       C_unsigned_int = C_unsigned, &
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       C_unsigned_short_int = C_short, &
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       C_unsigned_long_int = C_long, &
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       C_unsigned_long_long_int = C_long_long
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  interface C_F_string
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     module procedure C_F_string_ptr
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     module procedure C_F_string_chars
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  end interface C_F_string
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  interface F_C_string
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     module procedure F_C_string_ptr
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     module procedure F_C_string_chars
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  end interface F_C_string
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  !=======================================================================
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  !     Some useful ISO C library string functions from <string.h>
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  !     These are based on GCC header sections marked as NAMESPACE_STD
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  interface
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     !     Copy N bytes of SRC to DEST, no aliasing or overlapping allowed.
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     !     extern void *memcpy (void *dest, const void *src, size_t n);
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     function C_memcpy(dest, src, n) result(result) bind(C,name="memcpy")
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       import C_void_ptr, C_size_t
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       type(C_void_ptr) :: result
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       type(C_void_ptr), value, intent(in) :: dest ! target=intent(out)
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       type(C_void_ptr), value, intent(in) :: src ! target=intent(in)
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       integer(C_size_t), value, intent(in) :: n
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     end function C_memcpy
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     ! Copy N bytes of SRC to DEST, guaranteeing correct behavior for overlapping strings.
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     !extern void *memmove (void *dest, const void *src, size_t n)
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     function C_memmove(dest, src, n) result(result) bind(C,name="memmove")
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       import C_void_ptr, C_size_t
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       type(C_void_ptr) :: result
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       type(C_void_ptr), value, intent(in) :: dest ! target=intent(out)
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       type(C_void_ptr), value, intent(in) :: src
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       integer(C_size_t), value, intent(in) :: n
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     end function C_memmove
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     ! Set N bytes of S to C.
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     !extern void *memset (void *s, int c, size_t n)
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     function C_memset(s, c, n) result(result) bind(C,name="memset")
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       import C_void_ptr, C_int, C_size_t
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       type(C_void_ptr) :: result
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       type(C_void_ptr), value, intent(in) :: s ! target=intent(out)
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       integer(C_int), value, intent(in) :: c
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       integer(C_size_t), value, intent(in) :: n
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     end function C_memset
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     ! Compare N bytes of S1 and S2.
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     !extern int memcmp (const void *s1, const void *s2, size_t n)
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     pure function C_memcmp(s1, s2, n) result(result) bind(C,name="memcmp")
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       import C_int, C_void_ptr, C_size_t
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       integer(C_int) :: result
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       type(C_void_ptr), value, intent(in) :: s1
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       type(C_void_ptr), value, intent(in) :: s2
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       integer(C_size_t), value, intent(in) :: n
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     end function C_memcmp
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     ! Search N bytes of S for C.
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     !extern void *memchr (const void *s, int c, size_t n)
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     pure function C_memchr(s, c, n) result(result) bind(C,name="memchr")
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       import C_void_ptr, C_int, C_size_t
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       type(C_void_ptr) :: result
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       type(C_void_ptr), value, intent(in) :: s
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       integer(C_int), value, intent(in) :: c
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       integer(C_size_t), value, intent(in) :: n
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     end function C_memchr
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     ! Copy SRC to DEST.
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     !extern char *strcpy (char *dest, const char *src)
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     function C_strcpy(dest, src) result(result) bind(C,name="strcpy")
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       import C_char_ptr, C_size_t
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       type(C_char_ptr) :: result
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       type(C_char_ptr), value, intent(in) :: dest ! target=intent(out)
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       type(C_char_ptr), value, intent(in) :: src
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     end function C_strcpy
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     ! Copy no more than N characters of SRC to DEST.
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     !extern char *strncpy (char *dest, const char *src, size_t n)
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     function C_strncpy(dest, src, n) result(result) bind(C,name="strncpy")
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       import C_char_ptr, C_size_t
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       type(C_char_ptr) :: result
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       type(C_char_ptr), value, intent(in) :: dest ! target=intent(out)
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       type(C_char_ptr), value, intent(in) :: src
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       integer(C_size_t), value, intent(in) :: n
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     end function C_strncpy
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     ! Append SRC onto DEST.
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     !extern char *strcat (char *dest, const char *src)
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     function C_strcat(dest, src) result(result) bind(C,name="strcat")
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       import C_char_ptr, C_size_t
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       type(C_char_ptr) :: result
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       type(C_char_ptr), value, intent(in) :: dest ! target=intent(out)
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       type(C_char_ptr), value, intent(in) :: src
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     end function C_strcat
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     ! Append no more than N characters from SRC onto DEST.
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     !extern char *strncat (char *dest, const char *src, size_t n)
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     function C_strncat(dest, src, n) result(result) bind(C,name="strncat")
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       import C_char_ptr, C_size_t
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       type(C_char_ptr) :: result
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       type(C_char_ptr), value, intent(in) :: dest ! target=intent(out)
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       type(C_char_ptr), value, intent(in) :: src
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       integer(C_size_t), value, intent(in) :: n
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     end function C_strncat
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     ! Compare S1 and S2.
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     !extern int strcmp (const char *s1, const char *s2)
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     pure function C_strcmp(s1, s2) result(result) bind(C,name="strcmp")
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       import C_int, C_char_ptr, C_size_t
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       integer(C_int) :: result
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       type(C_char_ptr), value, intent(in) :: s1
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       type(C_char_ptr), value, intent(in) :: s2
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     end function C_strcmp
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     ! Compare N characters of S1 and S2.
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     !extern int strncmp (const char *s1, const char *s2, size_t n)
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     pure function C_strncmp(s1, s2, n) result(result) bind(C,name="strncmp")
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       import C_int, C_char_ptr, C_size_t
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       integer(C_int) :: result
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       type(C_char_ptr), value, intent(in) :: s1
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       type(C_char_ptr), value, intent(in) :: s2
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       integer(C_size_t), value, intent(in) :: n
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     end function C_strncmp
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     ! Return the length of S.
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     !extern size_t strlen (const char *s)
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     pure function C_strlen(s) result(result) bind(C,name="strlen")
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       import C_char_ptr, C_size_t
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       integer(C_size_t) :: result
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       type(C_char_ptr), value, intent(in) :: s  !character(len=*), intent(in)
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     end function C_strlen
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  end interface
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  ! End of <string.h>
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  !=========================================================================
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  ! Standard ISO-C malloc routines:
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  interface
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     ! void *calloc(size_t nmemb, size_t size);
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     type(C_void_ptr) function C_calloc(nmemb, size) bind(C,name="calloc")
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       import C_void_ptr, C_size_t
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       integer(C_size_t), value, intent(in) :: nmemb, size
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     end function C_calloc
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     ! void *malloc(size_t size);
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     type(C_void_ptr) function C_malloc(size) bind(C,name="malloc")
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       import C_void_ptr, C_size_t
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       integer(C_size_t), value, intent(in) :: size
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     end function C_malloc
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     ! void free(void *ptr);
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     subroutine C_free(ptr) bind(C,name="free")
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       import C_void_ptr
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       type(C_void_ptr), value, intent(in) :: ptr
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     end subroutine C_free
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     ! void *realloc(void *ptr, size_t size);
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     type(C_void_ptr) function C_realloc(ptr,size) bind(C,name="realloc")
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       import C_void_ptr, C_size_t
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       type(C_void_ptr), value, intent(in) :: ptr
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       integer(C_size_t), value, intent(in) :: size
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     end function C_realloc
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  end interface
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  interface assignment(=)
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     module procedure F_string_assign_C_string
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  end interface assignment(=)
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  !==========================================================================
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contains
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  ! HACK: For some reason, C_associated was not defined as pure.
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  pure logical function C_associated_pure(ptr) result(associated)
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    type(C_ptr), intent(in) :: ptr
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    integer(C_intptr_t) :: iptr
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    iptr = transfer(ptr,iptr)
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    associated = (iptr /= 0)
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  end function C_associated_pure
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  ! Set a fixed-length Fortran string to the value of a C string.
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  subroutine F_string_assign_C_string(F_string, C_string)
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    character(len=*), intent(out) :: F_string
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    type(C_ptr), intent(in) :: C_string
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    character(len=1,kind=C_char), pointer :: p_chars(:)
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    integer :: i
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    if (.not. C_associated(C_string) ) then
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       F_string = ' '
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    else
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       call C_F_pointer(C_string,p_chars,[huge(0)])
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       i=1
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       do while(p_chars(i)/=NUL .and. i<=len(F_string))
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          F_string(i:i) = p_chars(i)
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          i=i+1
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       end do
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       if (i<len(F_string)) F_string(i:) = ' '
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    end if
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  end subroutine F_string_assign_C_string
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  ! Copy a C string, passed by pointer, to a Fortran string.
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  ! If the C pointer is NULL, the Fortran string is blanked.
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  ! C_string must be NUL terminated, or at least as long as F_string.
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  ! If C_string is longer, it is truncated. Otherwise, F_string is
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  ! blank-padded at the end.
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  subroutine C_F_string_ptr(C_string, F_string)
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    type(C_ptr), intent(in) :: C_string
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    character(len=*), intent(out) :: F_string
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    character(len=1,kind=C_char), dimension(:), pointer :: p_chars
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    integer :: i
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    if (.not. C_associated(C_string)) then
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       F_string = ' '
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    else
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       call C_F_pointer(C_string,p_chars,[huge(0)])
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       i=1
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       do while(p_chars(i)/=NUL .and. i<=len(F_string))
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          F_string(i:i) = p_chars(i)
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          i=i+1
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       end do
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       if (i<len(F_string)) F_string(i:) = ' '
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    end if
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  end subroutine C_F_string_ptr
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  ! Copy a C string, passed as a char-array reference, to a Fortran string.
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  subroutine C_F_string_chars(C_string, F_string)
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    character(len=1,kind=C_char), intent(in) :: C_string(*)
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    character(len=*), intent(out) :: F_string
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    integer :: i
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    i=1
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    do while(C_string(i)/=NUL .and. i<=len(F_string))
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       F_string(i:i) = C_string(i)
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       i=i+1
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    end do
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    if (i<len(F_string)) F_string(i:) = ' '
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  end subroutine C_F_string_chars
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  ! Copy a Fortran string to an allocated C string pointer.
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  ! If the C pointer is NULL, no action is taken. (Maybe auto allocate via libc call?)
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  ! If the length is not passed, the C string must be at least: len(F_string)+1
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  ! If the length is passed and F_string is too long, it is truncated.
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  subroutine F_C_string_ptr(F_string, C_string, C_string_len)
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    character(len=*), intent(in) :: F_string
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    type(C_ptr), intent(in) :: C_string ! target = intent(out)
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    integer, intent(in), optional :: C_string_len  ! Max string length,
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    ! INCLUDING THE TERMINAL NUL
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    character(len=1,kind=C_char), dimension(:), pointer :: p_chars
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    integer :: i, strlen
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    strlen = len(F_string)
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    if (present(C_string_len)) then
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       if (C_string_len <= 0) return
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       strlen = min(strlen,C_string_len)
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    end if
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    if (.not. C_associated(C_string)) then
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       return
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    end if
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    call C_F_pointer(C_string,p_chars,[strlen+1])
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    forall (i=1:strlen)
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       p_chars(i) = F_string(i:i)
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    end forall
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    p_chars(strlen+1) = NUL
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  end subroutine F_C_string_ptr
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  pure function C_strlen_safe(s) result(length)
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    integer(C_size_t) :: length
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    type(C_char_ptr), value, intent(in) :: s
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    if (.not. C_associated_pure(s)) then
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       length = 0
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    else
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       length = C_strlen(s)
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    end if
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  end function C_strlen_safe
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  function C_string_value(C_string) result(F_string)
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    type(C_ptr), intent(in) :: C_string
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    character(len=C_strlen_safe(C_string)) :: F_string
 | 
						|
    character(len=1,kind=C_char), dimension(:), pointer :: p_chars
 | 
						|
    integer :: i, length
 | 
						|
    length = len(F_string)
 | 
						|
    if (length/=0) then
 | 
						|
       call C_F_pointer(C_string,p_chars,[length])
 | 
						|
       forall (i=1:length)
 | 
						|
          F_string(i:i) = p_chars(i)
 | 
						|
       end forall
 | 
						|
    end if
 | 
						|
  end function C_string_value
 | 
						|
 | 
						|
  ! Copy a Fortran string to a C string passed by char-array reference.
 | 
						|
  ! If the length is not passed, the C string must be at least: len(F_string)+1
 | 
						|
  ! If the length is passed and F_string is too long, it is truncated.
 | 
						|
  subroutine F_C_string_chars(F_string, C_string, C_string_len)
 | 
						|
    character(len=*), intent(in) :: F_string
 | 
						|
    character(len=1,kind=C_char), dimension(*), intent(out) :: C_string
 | 
						|
    integer, intent(in), optional :: C_string_len  ! Max string length,
 | 
						|
    ! INCLUDING THE TERMINAL NUL
 | 
						|
    integer :: i, strlen
 | 
						|
    strlen = len(F_string)
 | 
						|
    if (present(C_string_len)) then
 | 
						|
       if (C_string_len <= 0) return
 | 
						|
       strlen = min(strlen,C_string_len)
 | 
						|
    end if
 | 
						|
    forall (i=1:strlen)
 | 
						|
       C_string(i) = F_string(i:i)
 | 
						|
    end forall
 | 
						|
    C_string(strlen+1) = NUL
 | 
						|
  end subroutine F_C_string_chars
 | 
						|
 | 
						|
  ! NOTE: Strings allocated here must be freed by the
 | 
						|
  ! C library, such as via C_free() or C_string_free(),
 | 
						|
  type(C_ptr) function F_C_string_dup(F_string,length) result(C_string)
 | 
						|
    character(len=*), intent(in) :: F_string
 | 
						|
    integer, intent(in), optional :: length
 | 
						|
    character(len=1,kind=C_char), pointer :: C_string_ptr(:)
 | 
						|
    integer :: i
 | 
						|
    integer(C_size_t) :: strlen
 | 
						|
    if (present(length)) then
 | 
						|
       strlen = length
 | 
						|
    else
 | 
						|
       strlen = len(F_string)
 | 
						|
    end if
 | 
						|
    if (strlen <= 0) then
 | 
						|
       C_string = C_NULL_ptr
 | 
						|
    else
 | 
						|
       C_string = C_malloc(strlen+1)
 | 
						|
       if (C_associated(C_string)) then
 | 
						|
          call C_F_pointer(C_string,C_string_ptr,[strlen+1])
 | 
						|
          forall (i=1:strlen)
 | 
						|
             C_string_ptr(i) = F_string(i:i)
 | 
						|
          end forall
 | 
						|
          C_string_ptr(strlen+1) = NUL
 | 
						|
       end if
 | 
						|
    end if
 | 
						|
  end function F_C_string_dup
 | 
						|
 | 
						|
  ! NOTE: Strings allocated here must be freed by the
 | 
						|
  ! C library, such as via C_free() or C_string_free(),
 | 
						|
  type(C_ptr) function C_string_alloc(length) result(C_string)
 | 
						|
    integer(C_size_t), intent(in) :: length
 | 
						|
    character(len=1,kind=C_char), pointer :: C_charptr
 | 
						|
    C_string = C_malloc(length+1)
 | 
						|
    if (C_associated(C_string)) then
 | 
						|
       call C_F_pointer(C_string,C_charptr)
 | 
						|
       C_charptr = NUL
 | 
						|
    end if
 | 
						|
  end function C_string_alloc
 | 
						|
 | 
						|
  subroutine C_string_free(string)
 | 
						|
    type(C_ptr), intent(inout) :: string
 | 
						|
    if (C_associated(string)) then
 | 
						|
       call C_free(string)
 | 
						|
       string = C_NULL_ptr
 | 
						|
    end if
 | 
						|
  end subroutine C_string_free
 | 
						|
 | 
						|
end module C_interface_module
 |