120 lines
2.4 KiB
C
120 lines
2.4 KiB
C
/* vi: set sw=4 ts=4: */
|
|
/*
|
|
* Utility routines.
|
|
*
|
|
* Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
|
|
*
|
|
* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
|
|
*/
|
|
|
|
#include "libbb.h"
|
|
|
|
/* Used by NOFORK applets (e.g. cat) - must not use xmalloc */
|
|
|
|
static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
|
|
{
|
|
int status = -1;
|
|
off_t total = 0;
|
|
#if CONFIG_FEATURE_COPYBUF_KB <= 4
|
|
char buffer[CONFIG_FEATURE_COPYBUF_KB * 1024];
|
|
enum { buffer_size = sizeof(buffer) };
|
|
#else
|
|
char *buffer;
|
|
int buffer_size;
|
|
|
|
/* We want page-aligned buffer, just in case kernel is clever
|
|
* and can do page-aligned io more efficiently */
|
|
buffer = mmap(NULL, CONFIG_FEATURE_COPYBUF_KB * 1024,
|
|
PROT_READ | PROT_WRITE,
|
|
MAP_PRIVATE | MAP_ANON,
|
|
/* ignored: */ -1, 0);
|
|
buffer_size = CONFIG_FEATURE_COPYBUF_KB * 1024;
|
|
if (buffer == MAP_FAILED) {
|
|
buffer = alloca(4 * 1024);
|
|
buffer_size = 4 * 1024;
|
|
}
|
|
#endif
|
|
|
|
if (src_fd < 0)
|
|
goto out;
|
|
|
|
if (!size) {
|
|
size = buffer_size;
|
|
status = 1; /* copy until eof */
|
|
}
|
|
|
|
while (1) {
|
|
ssize_t rd;
|
|
|
|
rd = safe_read(src_fd, buffer, size > buffer_size ? buffer_size : size);
|
|
|
|
if (!rd) { /* eof - all done */
|
|
status = 0;
|
|
break;
|
|
}
|
|
if (rd < 0) {
|
|
bb_perror_msg(bb_msg_read_error);
|
|
break;
|
|
}
|
|
/* dst_fd == -1 is a fake, else... */
|
|
if (dst_fd >= 0) {
|
|
ssize_t wr = full_write(dst_fd, buffer, rd);
|
|
if (wr < rd) {
|
|
bb_perror_msg(bb_msg_write_error);
|
|
break;
|
|
}
|
|
}
|
|
total += rd;
|
|
if (status < 0) { /* if we aren't copying till EOF... */
|
|
size -= rd;
|
|
if (!size) {
|
|
/* 'size' bytes copied - all done */
|
|
status = 0;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
out:
|
|
|
|
#if CONFIG_FEATURE_COPYBUF_KB > 4
|
|
if (buffer_size != 4 * 1024)
|
|
munmap(buffer, buffer_size);
|
|
#endif
|
|
return status ? -1 : total;
|
|
}
|
|
|
|
|
|
#if 0
|
|
void complain_copyfd_and_die(off_t sz)
|
|
{
|
|
if (sz != -1)
|
|
bb_error_msg_and_die("short read");
|
|
/* if sz == -1, bb_copyfd_XX already complained */
|
|
xfunc_die();
|
|
}
|
|
#endif
|
|
|
|
off_t bb_copyfd_size(int fd1, int fd2, off_t size)
|
|
{
|
|
if (size) {
|
|
return bb_full_fd_action(fd1, fd2, size);
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
|
|
{
|
|
off_t sz = bb_copyfd_size(fd1, fd2, size);
|
|
if (sz == size)
|
|
return;
|
|
if (sz != -1)
|
|
bb_error_msg_and_die("short read");
|
|
/* if sz == -1, bb_copyfd_XX already complained */
|
|
xfunc_die();
|
|
}
|
|
|
|
off_t bb_copyfd_eof(int fd1, int fd2)
|
|
{
|
|
return bb_full_fd_action(fd1, fd2, 0);
|
|
}
|