UNIX环境高级编程习题 5.1

#include <stdio.h>

#include <stdlib.h>

void mysetbuf(FILE *__restrict fp, char *__restrict buf);

int main()

{

FILE *fp;

char buf[BUFSIZ];

if ((fp = fopen("test.mayjie","a+")) == NULL)

{

printf("fopen error!/n");

exit(-1);

}

mysetbuf(fp,buf);

mysetbuf(stdin,buf);

mysetbuf(stdout,buf);

mysetbuf(stderr,buf);

fclose(fp);

return 0;

}

void mysetbuf(FILE *__restrict fp, char *__restrict buf)

{

if (buf == NULL)

{

if (setvbuf(fp,NULL,_IONBF,0) != 0) /* 无缓冲 */

{

printf("setvbuf error!/n");

exit(-1);

}

}

else

{

if (fp == stderr)

{

if (setvbuf(fp,NULL,_IONBF,0) != 0) /* 无缓冲 */

{

printf("setvbuf error!/n");

exit(-1);

}

}

else if (fp == stdin || fp == stdout)

{

if (setvbuf(fp,buf,_IOLBF,BUFSIZ) != 0) /* 行缓冲 */

{

printf("setvbuf error!/n");

exit(-1);

}

}

else

{

if (setvbuf(fp,buf,_IOFBF,BUFSIZ) != 0) /* 全缓冲 */

{

printf("setvbuf error!/n");

exit(-1);

}

}

}

}