SETBUF(3) Linux Programmer's Manual SETBUF(3) NAME setbuf, setbuffer, setlinebuf, setvbuf - SYNOPSIS #include void setbuf(FILE *stream, char *buf); void setbuffer(FILE *stream, char *buf, size_t size); void setlinebuf(FILE *stream); int setvbuf(FILE *stream, char *buf, int mode , size_t size); DESCRIPTION ( stdin) fflush(3) ( fclose(3)) I/O malloc(3) ( stdout ) stderr setvbuf mode _IONBF _IOLBF _IOFBF buf size buf NULL read write setvbuf setvbuf setbuf setvbuf(stream, buf, buf ? _IOFBF : _IONBF, BUFSIZ); setbuffer BUFSIZ setlinebuf setvbuf(stream, (char *)NULL, _IOLBF, 0); RETURN VALUE setvbuf 0 It can return any value on failure, but returns nonzero when mode errno CONFORMING TO setbuf setvbuf ANSI X3.159-1989 (``ANSI C'') BUGS setbuffer setlinebuf 4.2BSD BSD Linux libc 4.5.21 4.2BSD 4.3BSD setbuf stream buf #include int main() { char buf[BUFSIZ]; setbuf(stdin, buf); printf("Hello, world!\n"); return 0; } SEE ALSO fclose(3), fflush(3), fopen(3), fread(3), malloc(3), printf(3), puts(3) man man https://github.com/man-pages-zh/manpages- zh Linux 2001-06-09 SETBUF(3)