Danh sách các hàm sử dụng In/Out
1.clearerr
2.fclose
3.feof
4.ferror
5.fflush
6.fgetc
7.fgetpos
8.fgets
9.fopen
10.fprintf
11.fputc
12.fputs
13.fread
14.freopen
15.fscanf
16.fseek
17.fsetpos
18.ftell
19.fwrite
20.getc
21.getchar
22.gets
23.perror
24.printf
25.putc
26.putchar
27.puts
28.remove
29.rename
30.rewind
31.scanf
32.setbuf
33.setvbuf
34.sprintf
35.sscanf
36.tmpfile
37.tmpnam
38.ungetc
39.vprintf, vfprintf, and vsprintf