dd46861282
Changed safe_read to be symmetrical to safe_write, it shall never return EINTR because it calls read multiple times, the error is considered transient. function old new delta safe_read 44 57 +13 Signed-off-by: Martin Lewis <martin.lewis.x84@gmail.com> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
81 lines
1.5 KiB
C
81 lines
1.5 KiB
C
/* vi: set sw=4 ts=4: */
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/*
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* Utility routines.
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*
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* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this source tree.
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*/
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#include "libbb.h"
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ssize_t FAST_FUNC safe_read(int fd, void *buf, size_t count)
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{
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ssize_t n;
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for (;;) {
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n = read(fd, buf, count);
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if (n >= 0 || errno != EINTR)
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break;
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/* Some callers set errno=0, are upset when they see EINTR.
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* Returning EINTR is wrong since we retry read(),
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* the "error" was transient.
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*/
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errno = 0;
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/* repeat the read() */
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}
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return n;
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}
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/*
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* Read all of the supplied buffer from a file.
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* This does multiple reads as necessary.
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* Returns the amount read, or -1 on an error.
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* A short read is returned on an end of file.
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*/
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ssize_t FAST_FUNC full_read(int fd, void *buf, size_t len)
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{
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ssize_t cc;
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ssize_t total;
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total = 0;
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while (len) {
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cc = safe_read(fd, buf, len);
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if (cc < 0) {
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if (total) {
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/* we already have some! */
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/* user can do another read to know the error code */
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return total;
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}
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return cc; /* read() returns -1 on failure. */
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}
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if (cc == 0)
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break;
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buf = ((char *)buf) + cc;
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total += cc;
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len -= cc;
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}
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return total;
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}
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ssize_t FAST_FUNC read_close(int fd, void *buf, size_t size)
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{
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/*int e;*/
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size = full_read(fd, buf, size);
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/*e = errno;*/
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close(fd);
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/*errno = e;*/
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return size;
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}
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ssize_t FAST_FUNC open_read_close(const char *filename, void *buf, size_t size)
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{
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int fd = open(filename, O_RDONLY);
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if (fd < 0)
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return fd;
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return read_close(fd, buf, size);
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}
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