ref: 994cbd04b19eceb893b8252c881993c4342d6bf1
dir: /sys/src/libstdio/setvbuf.c/
/* * pANS stdio -- setvbuf */ #include "iolib.h" int setvbuf(FILE *f, char *buf, int mode, long size){ if(f->state!=OPEN){ f->state=ERR; return -1; } f->state=RDWR; switch(mode){ case _IOLBF: f->flags|=LINEBUF; case _IOFBF: if(buf==0){ buf=malloc(size); if(buf==0){ f->state=ERR; return -1; } f->flags|=BALLOC; } f->bufl=size; break; case _IONBF: buf=f->unbuf; f->bufl=0; break; } f->rp=f->wp=f->lp=f->buf=buf; f->state=RDWR; return 0; } static int isatty(int fd) { char buf[64]; if(fd2path(fd, buf, sizeof buf) != 0) return 0; /* might be /mnt/term/dev/cons */ return strlen(buf) >= 9 && strcmp(buf+strlen(buf)-9, "/dev/cons") == 0; } int _IO_setvbuf(FILE *f){ if(f==stderr || (f==stdout && isatty(1))) return setvbuf(f, (char *)0, _IOLBF, BUFSIZ); else return setvbuf(f, (char *)0, _IOFBF, BUFSIZ); }