/* readline.c -- read a line of input
 * 
 * char	*line;
 * FILE	*cif;
 * FNL	*inf;
 * int	size;
 * size = readline(&line, &cif, &inf);
 * 
 * cif points to a currently open file (or is NULL if there
 * is none).  inf is a list of names of files to be read
 * when cif is exhausted.  readline reads a line, putting
 * it in space allocated from the heap.  A pointer to the
 * line is placed in line.  The terminal newline is replaced
 * with a '\0'.  The number of chars in the line (not including
 * the terminator) is returned.
 */
#include <stdio.h>
#include "common.h"
#include "readline.h"

char	*ealloc();
char	*erealloc();
int	strlen();
char	*igets();

int
readline(lp, ci, il)
char		**lp;
FILE		**ci;
FNL		**il;
{
    char		*b;		/* buffer			*/
    int			bs;		/* buffer size			*/
    char		*s;		/* current char pointer		*/
    int			sp;		/* space left			*/
    int			sl;

    b = ealloc(MINBUF);
    bs = MINBUF;
    s = b;
    sp = bs;
    for(;;) {
	if (NULL == igets(s, sp, ci, il)) return(EOF);
	sl = strlen(s);
	s += sl;
	sp -= sl;
	if ('\n' == s[-1]) break;
	if (1 >= sp) {
	    bs += MINBUF;
	    b = erealloc(b, bs);
	    sp += MINBUF;
	    s = b + bs - sp;
	}
    }
    s[-1] = '\0';
    *lp = b;
    return(bs - sp - 1);
}