xref: /aosp_15_r20/external/ltp/testcases/kernel/sched/clisrv/writen.c (revision 49cdfc7efb34551c7342be41a7384b9c40d7cab7)
1 /*
2  *   Copyright (c) International Business Machines  Corp., 2001
3  *
4  *   This program is free software;  you can redistribute it and/or modify
5  *   it under the terms of the GNU General Public License as published by
6  *   the Free Software Foundation; either version 2 of the License, or
7  *   (at your option) any later version.
8  *
9  *   This program is distributed in the hope that it will be useful,
10  *   but WITHOUT ANY WARRANTY;  without even the implied warranty of
11  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
12  *   the GNU General Public License for more details.
13  *
14  *   You should have received a copy of the GNU General Public License
15  *   along with this program;  if not, write to the Free Software
16  *   Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /******************************************************************************
20  *  writen.c
21  ******************************************************************************/
22 
23 #include <unistd.h>
24 
25 /* Write "n" bytes to a descriptor
26    Use instead of write() when fd is a stream socket. */
27 
writen(int fd,char * ptr,int nbytes)28 int writen(int fd, char *ptr, int nbytes)
29 {
30 	int nleft, nwritten;
31 
32 	nleft = nbytes;
33 	while (nleft > 0) {
34 		nwritten = write(fd, ptr, nleft);
35 		if (nwritten <= 0)
36 			return (nwritten);	/* error */
37 		nleft -= nwritten;
38 		ptr += nwritten;
39 	}
40 	return (nbytes - nleft);
41 }
42