[3320] | 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) 1999-2004 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 source tree.
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| 8 | */
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| 9 | #include "libbb.h"
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| 10 |
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| 11 | ssize_t FAST_FUNC safe_read(int fd, void *buf, size_t count)
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| 12 | {
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| 13 | ssize_t n;
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| 14 |
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| 15 | do {
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| 16 | n = read(fd, buf, count);
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| 17 | } while (n < 0 && errno == EINTR);
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| 18 |
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| 19 | return n;
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| 20 | }
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| 21 |
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| 22 | /*
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| 23 | * Read all of the supplied buffer from a file.
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| 24 | * This does multiple reads as necessary.
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| 25 | * Returns the amount read, or -1 on an error.
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| 26 | * A short read is returned on an end of file.
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| 27 | */
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| 28 | ssize_t FAST_FUNC full_read(int fd, void *buf, size_t len)
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| 29 | {
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| 30 | ssize_t cc;
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| 31 | ssize_t total;
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| 32 |
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| 33 | total = 0;
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| 34 |
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| 35 | while (len) {
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| 36 | cc = safe_read(fd, buf, len);
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| 37 |
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| 38 | if (cc < 0) {
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| 39 | if (total) {
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| 40 | /* we already have some! */
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| 41 | /* user can do another read to know the error code */
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| 42 | return total;
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| 43 | }
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| 44 | return cc; /* read() returns -1 on failure. */
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| 45 | }
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| 46 | if (cc == 0)
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| 47 | break;
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| 48 | buf = ((char *)buf) + cc;
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| 49 | total += cc;
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| 50 | len -= cc;
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| 51 | }
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| 52 |
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| 53 | return total;
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| 54 | }
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| 55 |
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| 56 | ssize_t FAST_FUNC read_close(int fd, void *buf, size_t size)
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| 57 | {
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| 58 | /*int e;*/
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| 59 | size = full_read(fd, buf, size);
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| 60 | /*e = errno;*/
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| 61 | close(fd);
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| 62 | /*errno = e;*/
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| 63 | return size;
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| 64 | }
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| 65 |
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| 66 | ssize_t FAST_FUNC open_read_close(const char *filename, void *buf, size_t size)
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| 67 | {
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| 68 | int fd = open(filename, O_RDONLY);
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| 69 | if (fd < 0)
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| 70 | return fd;
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| 71 | return read_close(fd, buf, size);
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| 72 | }
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