ref: 29c7ca80c9df8f805217be9bb9a9a083ff12912d
dir: /sys/src/libstdio/fwrite.c/
/* * pANS stdio -- fwrite */ #include "iolib.h" #define BIGN (BUFSIZ/2) long fwrite(const void *p, long recl, long nrec, FILE *f){ char *s; int n, d; s=(char *)p; n=recl*nrec; while(n>0){ d=f->rp-f->wp; if(d>0){ if(d>n) d=n; memmove(f->wp, s, d); f->wp+=d; }else{ if(n>=BIGN && f->state==WR && !(f->flags&(STRING|LINEBUF)) && f->buf!=f->unbuf){ d=f->wp-f->buf; if(d>0){ if(f->flags&APPEND) seek(f->fd, 0L, 2); if(write(f->fd, f->buf, d)!=d){ f->state=ERR; goto ret; } f->wp=f->rp=f->buf; } if(f->flags&APPEND) seek(f->fd, 0L, 2); d=write(f->fd, s, n); if(d<=0){ f->state=ERR; goto ret; } }else{ if(_IO_putc(*s, f)==EOF) goto ret; d=1; } } s+=d; n-=d; } ret: return (s-(char *)p)/(recl?recl:1); }