source: rtems/cpukit/libmisc/shell/dd-position.c @ 0893220

4.104.115
Last change on this file since 0893220 was 0893220, checked in by Ralf Corsepius <ralf.corsepius@…>, on Nov 29, 2009 at 12:12:39 PM

Whitespace removal.

  • Property mode set to 100644
File size: 5.2 KB
Line 
1/*-
2 * Copyright (c) 1991, 1993, 1994
3 *      The Regents of the University of California.  All rights reserved.
4 *
5 * This code is derived from software contributed to Berkeley by
6 * Keith Muller of the University of California, San Diego and Lance
7 * Visser of Convex Computer Corporation.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 *    notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 *    notice, this list of conditions and the following disclaimer in the
16 *    documentation and/or other materials provided with the distribution.
17 * 4. Neither the name of the University nor the names of its contributors
18 *    may be used to endorse or promote products derived from this software
19 *    without specific prior written permission.
20 *
21 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31 * SUCH DAMAGE.
32 */
33
34#ifndef lint
35#if 0
36static char sccsid[] = "@(#)position.c  8.3 (Berkeley) 4/2/94";
37#include <sys/cdefs.h>
38__FBSDID("$FreeBSD: src/bin/dd/position.c,v 1.23 2004/04/06 20:06:46 markm Exp $");
39#endif
40#endif /* not lint */
41
42#include <sys/types.h>
43#if RTEMS_REMOVED
44#include <sys/mtio.h>
45#endif
46
47#include <err.h>
48#include <errno.h>
49#include <inttypes.h>
50#include <unistd.h>
51
52#include "dd.h"
53#include "extern-dd.h"
54
55/*
56 * Position input/output data streams before starting the copy.  Device type
57 * dependent.  Seekable devices use lseek, and the rest position by reading.
58 * Seeking past the end of file can cause null blocks to be written to the
59 * output.
60 */
61void
62pos_in(rtems_shell_dd_globals* globals)
63{
64        off_t cnt;
65        int warned;
66        ssize_t nr;
67        size_t bcnt;
68
69        /* If known to be seekable, try to seek on it. */
70        if (in.flags & ISSEEK) {
71                errno = 0;
72                if (lseek(in.fd, in.offset * in.dbsz, SEEK_CUR) == -1 &&
73                    errno != 0)
74                        err(exit_jump, 1, "%s", in.name);
75                return;
76        }
77
78        /* Don't try to read a really weird amount (like negative). */
79        if (in.offset < 0)
80                errx(exit_jump, 1, "%s: illegal offset", "iseek/skip");
81
82        /*
83         * Read the data.  If a pipe, read until satisfy the number of bytes
84         * being skipped.  No differentiation for reading complete and partial
85         * blocks for other devices.
86         */
87        for (bcnt = in.dbsz, cnt = in.offset, warned = 0; cnt;) {
88                if ((nr = read(in.fd, in.db, bcnt)) > 0) {
89                        if (in.flags & ISPIPE) {
90                                if (!(bcnt -= nr)) {
91                                        bcnt = in.dbsz;
92                                        --cnt;
93                                }
94                        } else
95                                --cnt;
96                        continue;
97                }
98
99                if (nr == 0) {
100                        if (files_cnt > 1) {
101                                --files_cnt;
102                                continue;
103                        }
104                        errx(exit_jump, 1, "skip reached end of input");
105                }
106
107                /*
108                 * Input error -- either EOF with no more files, or I/O error.
109                 * If noerror not set die.  POSIX requires that the warning
110                 * message be followed by an I/O display.
111                 */
112                if (ddflags & C_NOERROR) {
113                        if (!warned) {
114                                warn("%s", in.name);
115                                warned = 1;
116                                summary(globals);
117                        }
118                        continue;
119                }
120                err(exit_jump, 1, "%s", in.name);
121        }
122}
123
124void
125pos_out(rtems_shell_dd_globals* globals)
126{
127#if RTEMS_REMOVED
128        struct mtop t_op;
129        off_t cnt;
130        ssize_t n;
131#endif
132
133        /*
134         * If not a tape, try seeking on the file.  Seeking on a pipe is
135         * going to fail, but don't protect the user -- they shouldn't
136         * have specified the seek operand.
137         */
138        if (out.flags & (ISSEEK | ISPIPE)) {
139                errno = 0;
140                if (lseek(out.fd, out.offset * out.dbsz, SEEK_CUR) == -1 &&
141                    errno != 0)
142                        err(exit_jump, 1, "%s", out.name);
143                return;
144        }
145
146        /* Don't try to read a really weird amount (like negative). */
147        if (out.offset < 0)
148                errx(exit_jump, 1, "%s: illegal offset", "oseek/seek");
149
150#if RTEMS_REMOVED
151        /* If no read access, try using mtio. */
152        if (out.flags & NOREAD) {
153                t_op.mt_op = MTFSR;
154                t_op.mt_count = out.offset;
155
156                if (ioctl(out.fd, MTIOCTOP, &t_op) == -1)
157                        err(1, "%s", out.name);
158                return;
159        }
160
161        /* Read it. */
162        for (cnt = 0; cnt < out.offset; ++cnt) {
163                if ((n = read(out.fd, out.db, out.dbsz)) > 0)
164                        continue;
165
166                if (n == -1)
167                        err(1, "%s", out.name);
168
169                /*
170                 * If reach EOF, fill with NUL characters; first, back up over
171                 * the EOF mark.  Note, cnt has not yet been incremented, so
172                 * the EOF read does not count as a seek'd block.
173                 */
174                t_op.mt_op = MTBSR;
175                t_op.mt_count = 1;
176                if (ioctl(out.fd, MTIOCTOP, &t_op) == -1)
177                        err(1, "%s", out.name);
178
179                while (cnt++ < out.offset) {
180                        n = write(out.fd, out.db, out.dbsz);
181                        if (n == -1)
182                                err(1, "%s", out.name);
183                        if ((size_t)n != out.dbsz)
184                                errx(1, "%s: write failure", out.name);
185                }
186                break;
187        }
188#endif
189}
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