1 [root@localhost ccode]# vim buff_type_test.c
 2 #include <stdio.h>
 3
 4 void pr_stdio(const char *, FILE *);
 5
 6 int main(void)
 7 {
 8     FILE *fp;
 9     fputs("enter andy character\n", stdout);
10     if(getchar() == EOF)
11         printf("getchar error");
12     fputs("one line to standard error\n", stderr);
13     pr_stdio("stdin", stdin);
14     pr_stdio("stdout", stdout);
15     pr_stdio("stderr", stderr);
16
17     if((fp = fopen("/etc/motd", "r")) == NULL)
18         printf("fopen error");
19     if(fgetc(fp) == EOF)
20         printf("get error");
21     pr_stdio("/etc/motd", fp);
22     return (0);
23 }
24
25 void pr_stdio(const char *name, FILE *fp)
26 {
27     printf("stream = %s, ", name);
28     if(fp->_flags & _IO_UNBUFFERED)
29         printf("unbuffered");
30     else if(fp->_flags & _IO_LINE_BUF)
31         printf("line buffered");
32     else
33         printf("fully buffered or modified");
34     printf(",buffer size = %d\n", fp->_IO_buf_end - fp->_IO_buf_base);
35 }
36
37 ~
38 ~
39 ~
40 ~
41 "buff_type_test.c" 35L, 824C written
42 [root@localhost ccode]# gcc -o buff_type_test buff_type_test.c
43 [root@localhost ccode]# ./buff_type_test
44 enter andy character
45 ytuy
46 one line to standard error
47 stream = stdin, line buffered,buffer size = 1024
48 stream = stdout, line buffered,buffer size = 1024
49 stream = stderr, unbuffered,buffer size = 1
50 get errorstream = /etc/motd, fully buffered or modified,buffer size = 4096