534374755d
xlseek and fdlength() for the new mkswap.
76 lines
1.4 KiB
C
76 lines
1.4 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) 1999-2005 by Erik Andersen <andersen@codepoet.org>
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*
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* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
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*/
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#include <errno.h>
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#include <stdlib.h>
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#include <string.h>
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#include <unistd.h>
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#include "libbb.h"
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#if BUFSIZ < 4096
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#undef BUFSIZ
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#define BUFSIZ 4096
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#endif
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static ssize_t bb_full_fd_action(int src_fd, int dst_fd, size_t size)
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{
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int status = -1;
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size_t total = 0;
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RESERVE_CONFIG_BUFFER(buffer,BUFSIZ);
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if (src_fd < 0) goto out;
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while (!size || total < size)
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{
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ssize_t wr, rd;
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rd = safe_read(src_fd, buffer,
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(!size || size - total > BUFSIZ) ? BUFSIZ : size - total);
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if (rd > 0) {
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/* A -1 dst_fd means we need to fake it... */
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wr = (dst_fd < 0) ? rd : full_write(dst_fd, buffer, rd);
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if (wr < rd) {
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bb_perror_msg(bb_msg_write_error);
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break;
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}
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total += wr;
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if (total == size) status = 0;
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} else if (rd < 0) {
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bb_perror_msg(bb_msg_read_error);
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break;
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} else if (rd == 0) {
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/* All done. */
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status = 0;
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break;
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}
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}
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out:
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RELEASE_CONFIG_BUFFER(buffer);
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return status ? status : (ssize_t)total;
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}
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int bb_copyfd_size(int fd1, int fd2, const off_t size)
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{
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if (size) {
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return(bb_full_fd_action(fd1, fd2, size));
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}
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return(0);
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}
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int bb_copyfd_eof(int fd1, int fd2)
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{
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return(bb_full_fd_action(fd1, fd2, 0));
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}
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