1 /* ========================================================================
2 * Copyright 1988-2006 University of Washington
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 *
11 * ========================================================================
12 */
13
14 /*
15 * Program: Write data, treating partial writes as an error
16 *
17 * Author: Mark Crispin
18 * Networks and Distributed Computing
19 * Computing & Communications
20 * University of Washington
21 * Administration Building, AG-44
22 * Seattle, WA 98195
23 * Internet: MRC@CAC.Washington.EDU
24 *
25 * Date: 26 May 1995
26 * Last Edited: 30 August 2006
27 */
28
29 /* The whole purpose of this unfortunate routine is to deal with DOS and
30 * certain cretinous versions of UNIX which decided that the "bytes actually
31 * written" return value from write() gave them license to use that for things
32 * that are really errors, such as disk quota exceeded, maximum file size
33 * exceeded, disk full, etc.
34 *
35 * BSD won't screw us this way on the local filesystem, but who knows what
36 * some NFS-mounted filesystem will do.
37 */
38
39 #undef write
40
41 /* Write data to file
42 * Accepts: file descriptor
43 * I/O vector structure
44 * number of vectors in structure
45 * Returns: number of bytes written if successful, -1 if failure
46 */
47
48 long maxposint = (long)((((unsigned long) 1) << ((sizeof(int) * 8) - 1)) - 1);
49
safe_write(int fd,char * buf,long nbytes)50 long safe_write (int fd,char *buf,long nbytes)
51 {
52 long i,j;
53 if (nbytes > 0) for (i = nbytes; i; i -= j,buf += j) {
54 while (((j = write (fd,buf,(int) min (maxposint,i))) < 0) &&
55 (errno == EINTR));
56 if (j < 0) return j;
57 }
58 return nbytes;
59 }
60