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| #include <sys/errno.h>
#include <string.h>
#include <stdlib.h>
#include <unistd.h>
#include "bio.h"
BFILE *bopen(const char *filename, const char *mode)
{
BFILE *stream;
int flags;
int fd;
char md;
if (strcmp(mode,"r") == 0) {
flags = O_RDONLY;
md = BMODE_READ;
} else {
errno = EINVAL;
return NULL;
}
if ((fd = open(filename, flags, PERM_FILE)) == -1)
return NULL;
if ((stream=(BFILE *)malloc(sizeof(BFILE)))!=NULL) {
stream->fd=fd;
stream->mode=md;
stream->pos=0;
}
return stream;
}
ssize_t bread(void *buf, ssize_t size, BFILE *stream)
{
char *ptr;
ssize_t more;
if ((stream==NULL)||(stream->mode!=BMODE_READ)) {
errno = EBADF;
return 0;
}
more=size;
ptr=buf;
while (stream->fill-stream->pos < more) {
memcpy(ptr,&stream->buf[stream->pos],stream->fill-stream->pos);
ptr+=stream->fill-stream->pos;
stream->pos=0;
if ((stream->fill=read(stream->fd,stream->buf,BBUFSIZ))<=0) {
stream->eof=(stream->fill==0);
stream->fill=0;
return size-more;
}
}
memcpy(ptr,&stream->buf[stream->pos],more);
stream->pos+=more;
return size;
}
int beof(BFILE *stream)
{
return stream->eof;
}
int bclose(BFILE *stream)
{
int r;
if (stream==NULL) {
errno = EBADF;
return BEOF;
}
if ((r=close(stream->fd))==0)
free(stream);
return r;
} |
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