拡張子を取得するサブルーチン

fortran

Fortran90で任意のファイル名(文字列)から拡張子を取得するサブルーチンを作りました。ちょっとだけググってそれらしいものが無かったので。

モジュールの形にして別ファイルにしています。

extension.f90

module m_extension
  implicit none

  public parse_filename

  integer(kind=8), parameter :: NAME_LEN = 80
  integer(kind=8), parameter :: EXT_LEN = 80

  contains

subroutine parse_filename(name, base, ext)
  character(len=NAME_LEN), intent(in) :: name
  character(len=NAME_LEN), intent(out) :: base
  character(len=EXT_LEN), intent(out) :: ext

  integer(kind=8) :: idot
  integer(kind=8) :: name_len

  idot = index(name, ".", back=.true.)
  name_len = len_trim(name)

  if( idot == 0) then
    base = name
  elseif( idot > 1) then
    base = name(1:idot-1)
  else
    base = ""
  endif

  if ( idot /= 0) then
    ext = name(idot+1:name_len)
  else
    ext = "" 
  endif
  
end subroutine parse_filename

end module m_extension

main.f90 (テスト用のメインルーチンです。)

program main
  use m_extension
  implicit none

  character(len=NAME_LEN) :: filename
  character(len=NAME_LEN) :: basename
  character(len=EXT_LEN)  :: extension

  ! test 1
  write(*,*) "# test 1"
  filename = "sample.hoge.txt"
  write(*,*) "filename  = ", trim(filename)

  write(*,*) "## parse_filename"
  call parse_filename(filename, basename, extension)

  write(*,*) "basename  = ", trim(basename)
  write(*,*) "extension = ", trim(extension)

  ! test 2
  write(*,*) "# test 2"
  filename = "sample"
  write(*,*) "filename  = ", trim(filename)

  write(*,*) "## parse_filename"
  call parse_filename(filename, basename, extension)

  write(*,*) "basename  = ", trim(basename)
  write(*,*) "extension = ", trim(extension)

end program main

Makefile

FC=ifort
FCFLAGS=-O3
LDFLAGS=-I.

OBJS=m_extension.o
MODULES=m_extension.mod

main: main.f90 $(OBJS)
	$(FC) $(FCFLAGS) -o $@ $< $(OBJS)

.SUFFIXES:
.SUFFIXES: .f90 .o .mod
.f90.o:
	$(FC) $(FCFLAGS) -c -o $@ $<
.f90.mod:
	$(FC) $(FCFLAGS) -c -o $@ $<

clean:
	$(RM) -f main $(OBJS) $(MODULES)