testcases/kernel/sched/clisrv/readline.c

/*
 *   Copyright (c) International Business Machines  Corp., 2001
 *
 *   This program is free software;  you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation; either version 2 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
 *   the GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program;  if not, write to the Free Software
 *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/*****************************************************************************
 *  readline.c
 ******************************************************************************/

#include <unistd.h>

/* Read line from a descriptor, byte at a time, return number of
   characters up to the null */

int readline(fd, ptr, maxlen)
register int fd;
register char *ptr;
register int maxlen;
{
    int n, rc;
    char c;
    /*
    printf("readline: fd = %d\n", fd);
    */
    for (n =1; n < maxlen; n++)
	{
	if ((rc = read(fd, &c, 1)) == 1)
	    {
	    *ptr++ = c;
	    if (c == '\n')
		break;
	    }
	else if (rc == 0)
	    {
	    if (n ==1)
		return 0; /* EOF no data read */
	    else
		break; /* EOF, some data read */
	    }
	else
	    return(-1); /* error */
	}
    *ptr = 0;
    return(n);
}