/************************************************************************
 *									*
 *			Copyright (c) 1982, Fred Fish			*
 *			    All Rights Reserved				*
 *									*
 *	This software and/or documentation is released for public	*
 *	distribution for personal, non-commercial use only.		*
 *	Limited rights to use, modify, and redistribute are hereby	*
 *	granted for non-commercial purposes, provided that all		*
 *	copyright notices remain intact and all changes are clearly	*
 *	documented.  The author makes no warranty of any kind with	*
 *	respect to this product and explicitly disclaims any implied	*
 *	warranties of merchantability or fitness for any particular	*
 *	purpose.							*
 *									*
 ************************************************************************
 */
/*
 *  MODIFIED
 *
 *	21-Jul-88, T.R.Hageman, AZG, Groningen,
 *		removed tail recursion.
 *
 */

/*
 *  LIBRARY FUNCTION
 *
 *	fgetlr	  get logical record from a file
 *
 *  KEY WORDS
 *
 *	fgetlr
 *	string functions
 *
 *  SYNOPSIS
 *
 *	char *fgetlr (bp, bpsize, fp)
 *	char *bp;
 *	int bpsize;
 *	FILE *fp;
 *
 *  DESCRIPTION
 *
 *	Reads the next logical record from stream "fp" into buffer "bp"
 *	until next unescaped newline, "bpsize" minus one characters
 *	have been read, end of file, or read error.
 *	The last character read is followed by a NULL.
 *
 *	A logical record may span several physical records by having
 *	each newline escaped with the standard C escape character
 *	(backslash).
 *
 *	This is particularly useful for things like the termcap
 *	file, where a single entry is too long for one physical
 *	line, yet needs to be treated as a single record.
 *
 *	Returns its first argument unless an end of file or read
 *	error occurs prior to any characters being read.
 *
 *  BUGS
 *
 *	The only way to know if read was terminated due to buffer size
 *	limitation is to test for a newline before the terminating
 *	null.
 *
 */

#include <stdio.h>

/*
 *  PSEUDO CODE
 *
 *	Begin fgetlr
 *	    If read fails then
 *		Return NULL.
 *	    Else
 *		Find out how many characters were read.
 *		Initialize pointer to terminating null.
 *		If last char read was newline then
 *		    If newline was escaped then
 *			Replace backslash with the newline.
 *			Replace newline with null.
 *			Read and append more.
 *		    End if
 *		End if
 *		Return buffer pointer.
 *	    End if
 *	End fgetlr
 *
 */

char *
fgetlr (bp, bpsize, fp)
char		*bp;
int		bpsize;
register FILE	*fp;
{
	register int	c;
	register char	*cp = bp,
			*ep = &cp[bpsize - 1];

	while (cp < ep && (c = getc(fp)) != EOF) {
		if ((*cp++ = c) == '\n') {
			if (--cp > bp && cp[-1] == '\\') {
				cp[-1] = *cp;		/* i.e. newline */
			} else {
				cp++;
				break;
			}
		}
	}
	*cp = '\0';
	return (cp == bp) ? NULL : bp;

} /* fgetlr */