jehanne/sys/src/lib/stdio/fwrite.c

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/*
* This file is part of the UCB release of Plan 9. It is subject to the license
* terms in the LICENSE file found in the top-level directory of this
* distribution and at http://akaros.cs.berkeley.edu/files/Plan9License. No
* part of the UCB release of Plan 9, including this file, may be copied,
* modified, propagated, or distributed except according to the terms contained
* in the LICENSE file.
*/
/*
* pANS stdio -- fwrite
*/
#include "iolib.h"
#define BIGN (BUFSIZ/2)
int32_t fwrite(const void *p, int32_t recl, int32_t 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);
}