1 /* Utility functions for decompression helpers
2  *
3  * Copyright (c) 2009 Hans de Goede <hdegoede@redhat.com>
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  */
26 
27 #include <stdio.h>
28 #include <stdlib.h>
29 #include <unistd.h>
30 #include <errno.h>
31 #include <string.h>
32 
v4lconvert_helper_write(int fd,const void * b,size_t count,char * progname)33 static int v4lconvert_helper_write(int fd, const void *b, size_t count,
34   char *progname)
35 {
36   const unsigned char *buf = b;
37   size_t ret, written = 0;
38 
39   while (written < count) {
40     ret = write(fd, buf + written, count - written);
41     if (ret == -1) {
42       if (errno == EINTR)
43 	continue;
44 
45       if (errno == EPIPE) /* Main program has quited */
46 	exit(0);
47 
48       fprintf(stderr, "%s: error writing: %s\n", progname, strerror(errno));
49       return -1;
50     }
51     written += ret;
52   }
53 
54   return 0;
55 }
56 
v4lconvert_helper_read(int fd,void * b,size_t count,char * progname)57 static int v4lconvert_helper_read(int fd, void *b, size_t count,
58   char *progname)
59 {
60   unsigned char *buf = b;
61   size_t ret, r = 0;
62 
63   while (r < count) {
64     ret = read(fd, buf + r, count - r);
65     if (ret == -1) {
66       if (errno == EINTR)
67 	continue;
68 
69       fprintf(stderr, "%s: error reading: %s\n", progname, strerror(errno));
70       return -1;
71     }
72     if (ret == 0) /* EOF */
73       exit(0);
74 
75     r += ret;
76   }
77 
78   return 0;
79 }
80