readline.c

/*--- readline.c -> read a text line from a descriptor, one byte at a time ---*/
#include "meow.h"
static int read_cnt;
static char *read_ptr;
static char read_buf[MAXLINE];
static ssize_t my_read(int fd, char *ptr)
{
	if(read_cnt <= 0)
	{
meow:
		if((read_cnt = read(fd, read_buf, sizeof(read_buf))) < 0)
		{
			if(errno == EINTR)
				goto meow;
			return(-1);
		}
		else if(read_cnt == 0)
			return(0);
		read_ptr = read_buf;
	}
	read_cnt--;
	*ptr = *read_ptr++;
	return(1);
}
ssize_t readline(int fd, void *vptr, size_t maxlen)
{
	ssize_t n, rc;
	char c, *ptr;
	ptr = vptr;
	for(n=1;n<maxlen;n++)
	{
		if((rc=my_read(fd,&c)) == 1)
		{
			*ptr++ = c;
			if(c == '\n')
				break; /*newline is stored */
		}
		else if(rc == 0)
		{
			*ptr = 0;
			return(n - 1); /* n-1 bytes were read */
		}
		else
			return(-1); /*error*/
	}
	*ptr = 0; /* null terminate */
	return(n);
}
ssize_t readlinebuf(void **vptrptr)
{
	if(read_cnt)
		*vptrptr = read_ptr;
	return(read_cnt);
}