[BACK]Return to position.c CVS log [TXT][DIR] Up to [cvs.NetBSD.org] / src / bin / dd

Annotation of src/bin/dd/position.c, Revision 1.18

1.18    ! pooka       1: /*     $NetBSD: position.c,v 1.17 2009/02/14 07:13:40 lukem Exp $      */
1.4       cgd         2:
1.1       glass       3: /*-
1.3       mycroft     4:  * Copyright (c) 1991, 1993, 1994
                      5:  *     The Regents of the University of California.  All rights reserved.
1.1       glass       6:  *
                      7:  * This code is derived from software contributed to Berkeley by
                      8:  * Keith Muller of the University of California, San Diego and Lance
                      9:  * Visser of Convex Computer Corporation.
                     10:  *
                     11:  * Redistribution and use in source and binary forms, with or without
                     12:  * modification, are permitted provided that the following conditions
                     13:  * are met:
                     14:  * 1. Redistributions of source code must retain the above copyright
                     15:  *    notice, this list of conditions and the following disclaimer.
                     16:  * 2. Redistributions in binary form must reproduce the above copyright
                     17:  *    notice, this list of conditions and the following disclaimer in the
                     18:  *    documentation and/or other materials provided with the distribution.
1.14      agc        19:  * 3. Neither the name of the University nor the names of its contributors
1.1       glass      20:  *    may be used to endorse or promote products derived from this software
                     21:  *    without specific prior written permission.
                     22:  *
                     23:  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
                     24:  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
                     25:  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
                     26:  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
                     27:  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
                     28:  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
                     29:  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
                     30:  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
                     31:  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
                     32:  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
                     33:  * SUCH DAMAGE.
                     34:  */
                     35:
1.5       christos   36: #include <sys/cdefs.h>
1.1       glass      37: #ifndef lint
1.4       cgd        38: #if 0
                     39: static char sccsid[] = "@(#)position.c 8.3 (Berkeley) 4/2/94";
                     40: #else
1.18    ! pooka      41: __RCSID("$NetBSD: position.c,v 1.17 2009/02/14 07:13:40 lukem Exp $");
1.4       cgd        42: #endif
1.1       glass      43: #endif /* not lint */
                     44:
                     45: #include <sys/types.h>
                     46: #include <sys/stat.h>
                     47: #include <sys/ioctl.h>
                     48: #include <sys/mtio.h>
1.10      ross       49: #include <sys/time.h>
1.3       mycroft    50:
                     51: #include <err.h>
1.1       glass      52: #include <errno.h>
1.13      jschauma   53: #include <stdlib.h>
1.3       mycroft    54: #include <string.h>
1.1       glass      55: #include <unistd.h>
1.3       mycroft    56:
1.1       glass      57: #include "dd.h"
                     58: #include "extern.h"
                     59:
                     60: /*
                     61:  * Position input/output data streams before starting the copy.  Device type
                     62:  * dependent.  Seekable devices use lseek, and the rest position by reading.
                     63:  * Seeking past the end of file can cause null blocks to be written to the
                     64:  * output.
                     65:  */
                     66: void
1.11      lukem      67: pos_in(void)
1.1       glass      68: {
1.3       mycroft    69:        int bcnt, cnt, nr, warned;
1.1       glass      70:
1.8       jtk        71:        /* If not a pipe or tape device, try to seek on it. */
1.7       mycroft    72:        if (!(in.flags & (ISPIPE|ISTAPE))) {
1.18    ! pooka      73:                if (ddop_lseek(in, in.fd,
1.13      jschauma   74:                    (off_t)in.offset * (off_t)in.dbsz, SEEK_CUR) == -1) {
1.16      jschauma   75:                        err(EXIT_FAILURE, "%s", in.name);
1.13      jschauma   76:                        /* NOTREACHED */
                     77:                }
1.1       glass      78:                return;
1.13      jschauma   79:                /* NOTREACHED */
1.1       glass      80:        }
                     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;) {
1.18    ! pooka      88:                if ((nr = ddop_read(in, in.fd, in.db, bcnt)) > 0) {
1.1       glass      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:                        }
1.13      jschauma  104:                        errx(EXIT_FAILURE, "skip reached end of input");
                    105:                        /* NOTREACHED */
1.1       glass     106:                }
                    107:
                    108:                /*
                    109:                 * Input error -- either EOF with no more files, or I/O error.
                    110:                 * If noerror not set die.  POSIX requires that the warning
                    111:                 * message be followed by an I/O display.
                    112:                 */
                    113:                if (ddflags & C_NOERROR) {
                    114:                        if (!warned) {
1.15      kleink    115:
1.16      jschauma  116:                                warn("%s", in.name);
1.1       glass     117:                                warned = 1;
1.3       mycroft   118:                                summary();
1.1       glass     119:                        }
                    120:                        continue;
                    121:                }
1.16      jschauma  122:                err(EXIT_FAILURE, "%s", in.name);
1.13      jschauma  123:                /* NOTREACHED */
1.1       glass     124:        }
                    125: }
                    126:
                    127: void
1.11      lukem     128: pos_out(void)
1.1       glass     129: {
                    130:        struct mtop t_op;
1.17      lukem     131:        int n;
                    132:        uint64_t cnt;
1.1       glass     133:
                    134:        /*
                    135:         * If not a tape, try seeking on the file.  Seeking on a pipe is
                    136:         * going to fail, but don't protect the user -- they shouldn't
                    137:         * have specified the seek operand.
                    138:         */
                    139:        if (!(out.flags & ISTAPE)) {
1.18    ! pooka     140:                if (ddop_lseek(out, out.fd,
1.6       phil      141:                    (off_t)out.offset * (off_t)out.dbsz, SEEK_SET) == -1)
1.16      jschauma  142:                        err(EXIT_FAILURE, "%s", out.name);
1.13      jschauma  143:                        /* NOTREACHED */
1.1       glass     144:                return;
                    145:        }
                    146:
                    147:        /* If no read access, try using mtio. */
                    148:        if (out.flags & NOREAD) {
                    149:                t_op.mt_op = MTFSR;
                    150:                t_op.mt_count = out.offset;
                    151:
1.18    ! pooka     152:                if (ddop_ioctl(out, out.fd, MTIOCTOP, &t_op) < 0)
1.16      jschauma  153:                        err(EXIT_FAILURE, "%s", out.name);
1.13      jschauma  154:                        /* NOTREACHED */
1.1       glass     155:                return;
                    156:        }
                    157:
                    158:        /* Read it. */
                    159:        for (cnt = 0; cnt < out.offset; ++cnt) {
1.18    ! pooka     160:                if ((n = ddop_read(out, out.fd, out.db, out.dbsz)) > 0)
1.1       glass     161:                        continue;
                    162:
                    163:                if (n < 0)
1.16      jschauma  164:                        err(EXIT_FAILURE, "%s", out.name);
1.13      jschauma  165:                        /* NOTREACHED */
1.1       glass     166:
                    167:                /*
                    168:                 * If reach EOF, fill with NUL characters; first, back up over
                    169:                 * the EOF mark.  Note, cnt has not yet been incremented, so
                    170:                 * the EOF read does not count as a seek'd block.
                    171:                 */
                    172:                t_op.mt_op = MTBSR;
                    173:                t_op.mt_count = 1;
1.18    ! pooka     174:                if (ddop_ioctl(out, out.fd, MTIOCTOP, &t_op) == -1)
1.16      jschauma  175:                        err(EXIT_FAILURE, "%s", out.name);
1.13      jschauma  176:                        /* NOTREACHED */
1.1       glass     177:
                    178:                while (cnt++ < out.offset)
1.18    ! pooka     179:                        if ((uint64_t)(n = bwrite(&out,
        !           180:                            out.db, out.dbsz)) != out.dbsz)
1.16      jschauma  181:                                err(EXIT_FAILURE, "%s", out.name);
1.13      jschauma  182:                                /* NOTREACHED */
1.1       glass     183:                break;
                    184:        }
                    185: }

CVSweb <webmaster@jp.NetBSD.org>