$ icc -c func.c
$ ifort -c main.f90
$ ifort -o main main.o func.o
$ ./main
C function
str_src: hoge  , strlen(str_src): 6
str_dst: hoge  , strlen(str_dst): 6
 Fortran program
 str_src: hoge  , len_trim(str_src):           4
 str_dst: hoge     , len_trim(str_dst):           7
 str_src:
 1 01101000 h
 2 01101111 o
 3 01100111 g
 4 01100101 e
 5 00100000
 6 00100000
 str_dst:
 1 01101000 h
 2 01101111 o
 3 01100111 g
 4 01100101 e
 5 00100000
 6 00100000
 7 00000000
 8 00100000
 9 00100000
10 00100000