1 /* vi: set sw=4 ts=4: */
5 * Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
7 * Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
12 /* Used by NOFORK applets (e.g. cat) - must not use xmalloc */
14 static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
18 #if CONFIG_FEATURE_COPYBUF_KB <= 4
19 char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024];
20 enum { buffer_size = sizeof(buffer) };
25 if (size > 0 && size <= 4 * 1024)
27 /* We want page-aligned buffer, just in case kernel is clever
28 * and can do page-aligned io more efficiently */
29 buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024,
30 PROT_READ | PROT_WRITE,
31 MAP_PRIVATE | MAP_ANON,
32 /* ignored: */ -1, 0);
33 buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024;
34 if (buffer == MAP_FAILED) {
36 buffer = alloca(4 * 1024);
37 buffer_size = 4 * 1024;
46 status = 1; /* copy until eof */
52 rd = safe_read(src_fd, buffer, size > buffer_size ? buffer_size : size);
54 if (!rd) { /* eof - all done */
59 bb_perror_msg(bb_msg_read_error);
62 /* dst_fd == -1 is a fake, else... */
64 ssize_t wr = full_write(dst_fd, buffer, rd);
66 bb_perror_msg(bb_msg_write_error);
71 if (status < 0) { /* if we aren't copying till EOF... */
74 /* 'size' bytes copied - all done */
82 #if CONFIG_FEATURE_COPYBUF_KB > 4
83 if (buffer_size != 4 * 1024)
84 munmap(buffer, buffer_size);
86 return status ? -1 : total;
91 void FAST_FUNC complain_copyfd_and_die(off_t sz)
94 bb_error_msg_and_die("short read");
95 /* if sz == -1, bb_copyfd_XX already complained */
100 off_t FAST_FUNC bb_copyfd_size(int fd1, int fd2, off_t size)
103 return bb_full_fd_action(fd1, fd2, size);
108 void FAST_FUNC bb_copyfd_exact_size(int fd1, int fd2, off_t size)
110 off_t sz = bb_copyfd_size(fd1, fd2, size);
114 bb_error_msg_and_die("short read");
115 /* if sz == -1, bb_copyfd_XX already complained */
119 off_t FAST_FUNC bb_copyfd_eof(int fd1, int fd2)
121 return bb_full_fd_action(fd1, fd2, 0);