1 | /* vi: set sw=4 ts=4: */
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2 | /*
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3 | * Utility routines.
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4 | *
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5 | * Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
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6 | *
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7 | * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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8 | */
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9 |
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10 | #include "libbb.h"
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11 |
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12 | #if BUFSIZ < 4096
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13 | #undef BUFSIZ
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14 | #define BUFSIZ 4096
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15 | #endif
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16 |
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17 | /* Used by NOFORK applets (e.g. cat) - must not use xmalloc */
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18 |
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19 | static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
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20 | {
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21 | int status = -1;
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22 | off_t total = 0;
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23 | char buffer[BUFSIZ];
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24 |
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25 | if (src_fd < 0)
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26 | goto out;
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27 |
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28 | if (!size) {
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29 | size = BUFSIZ;
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30 | status = 1; /* copy until eof */
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31 | }
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32 |
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33 | while (1) {
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34 | ssize_t rd;
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35 |
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36 | rd = safe_read(src_fd, buffer, size > BUFSIZ ? BUFSIZ : size);
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37 |
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38 | if (!rd) { /* eof - all done */
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39 | status = 0;
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40 | break;
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41 | }
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42 | if (rd < 0) {
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43 | bb_perror_msg(bb_msg_read_error);
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44 | break;
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45 | }
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46 | /* dst_fd == -1 is a fake, else... */
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47 | if (dst_fd >= 0) {
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48 | ssize_t wr = full_write(dst_fd, buffer, rd);
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49 | if (wr < rd) {
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50 | bb_perror_msg(bb_msg_write_error);
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51 | break;
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52 | }
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53 | }
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54 | total += rd;
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55 | if (status < 0) { /* if we aren't copying till EOF... */
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56 | size -= rd;
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57 | if (!size) {
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58 | /* 'size' bytes copied - all done */
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59 | status = 0;
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60 | break;
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61 | }
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62 | }
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63 | }
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64 | out:
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65 | return status ? -1 : total;
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66 | }
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67 |
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68 |
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69 | #if 0
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70 | void complain_copyfd_and_die(off_t sz)
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71 | {
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72 | if (sz != -1)
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73 | bb_error_msg_and_die("short read");
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74 | /* if sz == -1, bb_copyfd_XX already complained */
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75 | xfunc_die();
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76 | }
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77 | #endif
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78 |
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79 | off_t bb_copyfd_size(int fd1, int fd2, off_t size)
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80 | {
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81 | if (size) {
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82 | return bb_full_fd_action(fd1, fd2, size);
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83 | }
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84 | return 0;
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85 | }
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86 |
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87 | void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
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88 | {
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89 | off_t sz = bb_copyfd_size(fd1, fd2, size);
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90 | if (sz == size)
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91 | return;
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92 | if (sz != -1)
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93 | bb_error_msg_and_die("short read");
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94 | /* if sz == -1, bb_copyfd_XX already complained */
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95 | xfunc_die();
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96 | }
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97 |
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98 | off_t bb_copyfd_eof(int fd1, int fd2)
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99 | {
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100 | return bb_full_fd_action(fd1, fd2, 0);
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101 | }
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