P8000/WEGA/contrib/lcc/lib/libc/port/stdio/fgets.c

46 lines
949 B
C

/*
* This version reads directly from the buffer rather than looping on getc.
* Ptr args aren't checked for NULL because the program would be a
* catastrophic mess anyway. Better to abort than just to return NULL.
*/
#include <stdio.h>
#include "stdiom.h"
#define MIN(x, y) (x < y ? x : y)
extern int _filbuf();
extern char *memccpy();
char *
fgets(ptr, size, iop)
char *ptr;
register int size;
register FILE *iop;
{
char *p, *ptr0 = ptr;
register int n;
for (size--; size > 0; size -= n) {
if (iop->_cnt <= 0) { /* empty buffer */
if (_filbuf(iop) == EOF) {
if (ptr0 == ptr)
return (NULL);
break; /* no more data */
}
iop->_ptr--;
iop->_cnt++;
}
n = MIN(size, iop->_cnt);
if ((p = memccpy(ptr, (char *) iop->_ptr, '\n', n)) != NULL)
n = p - ptr;
ptr += n;
iop->_cnt -= n;
iop->_ptr += n;
_BUFSYNC(iop);
if (p != NULL)
break; /* found '\n' in buffer */
}
*ptr = '\0';
return (ptr0);
}