trunk/libsbutil/sb_read.c

/*
 * sb_write.c
 *
 * IO functions.
 *
 * Copyright 1999-2006 Gentoo Foundation
 *
 *
 *      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 version 2 of the License.
 *
 *      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.,
 *      675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * $Header$
 */


#include <errno.h>
#include <stdio.h>
#include <sys/stat.h>
#include <unistd.h>
#include <fcntl.h>

#include "sbutil.h"


/* General purpose function to _reliably_ read from a file.
 *
 * Returns total read bytes or -1 on error.
 */

size_t sb_read(int fd, void *buf, size_t count)
{
        ssize_t n;
        size_t accum = 0;

        do {
                n = read(fd, buf + accum, count - accum);

                if (n > 0) {
                        accum += n;
                        continue;
                }

                if (n < 0) {
                        if (EINTR == errno) {
                                /* Reset errno to not trigger DBG_MSG */
                                errno = 0;
                                continue;
                        }

                        DBG_MSG("Failed to read from fd=%i!\n", fd);
                        return -1;
                }

                /* Found EOF */
                break;
        } while (accum < count);

        return accum;
}

1	/*
2	* sb_write.c
3	*
4	* IO functions.
5	*
6	* Copyright 1999-2006 Gentoo Foundation
7	*
8	*
9	* This program is free software; you can redistribute it and/or modify it
10	* under the terms of the GNU General Public License as published by the
11	* Free Software Foundation version 2 of the License.
12	*
13	* This program is distributed in the hope that it will be useful, but
14	* WITHOUT ANY WARRANTY; without even the implied warranty of
15	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16	* General Public License for more details.
17	*
18	* You should have received a copy of the GNU General Public License along
19	* with this program; if not, write to the Free Software Foundation, Inc.,
20	* 675 Mass Ave, Cambridge, MA 02139, USA.
21	*
22	* $Header$
23	*/
24
25
26	#include <errno.h>
27	#include <stdio.h>
28	#include <sys/stat.h>
29	#include <unistd.h>
30	#include <fcntl.h>
31
32	#include "sbutil.h"
33
34
35	/* General purpose function to _reliably_ read from a file.
36	*
37	* Returns total read bytes or -1 on error.
38	*/
39
40	size_t sb_read(int fd, void *buf, size_t count)
41	{
42	ssize_t n;
43	size_t accum = 0;
44
45	do {
46	n = read(fd, buf + accum, count - accum);
47
48	if (n > 0) {
49	accum += n;
50	continue;
51	}
52
53	if (n < 0) {
54	if (EINTR == errno) {
55	/* Reset errno to not trigger DBG_MSG */
56	errno = 0;
57	continue;
58	}
59
60	DBG_MSG("Failed to read from fd=%i!\n", fd);
61	return -1;
62	}
63
64	/* Found EOF */
65	break;
66	} while (accum < count);
67
68	return accum;
69	}
70