hush/libbb/copyfd.c

74 lines
1.3 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 <errno.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include "libbb.h"
#if BUFSIZ < 4096
#undef BUFSIZ
#define BUFSIZ 4096
#endif
static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
{
int status = -1;
off_t total = 0;
RESERVE_CONFIG_BUFFER(buffer,BUFSIZ);
if (src_fd < 0) goto out;
while (!size || total < size) {
ssize_t wr, rd;
rd = safe_read(src_fd, buffer,
(!size || size - total > BUFSIZ) ? BUFSIZ : size - total);
if (rd > 0) {
/* A -1 dst_fd means we need to fake it... */
wr = (dst_fd < 0) ? rd : full_write(dst_fd, buffer, rd);
if (wr < rd) {
bb_perror_msg(bb_msg_write_error);
break;
}
total += wr;
if (total == size) status = 0;
} else if (rd < 0) {
bb_perror_msg(bb_msg_read_error);
break;
} else { /* eof - all done. */
status = 0;
break;
}
}
out:
RELEASE_CONFIG_BUFFER(buffer);
return status ? status : total;
}
off_t bb_copyfd_size(int fd1, int fd2, off_t size)
{
if (size) {
return bb_full_fd_action(fd1, fd2, size);
}
return 0;
}
off_t bb_copyfd_eof(int fd1, int fd2)
{
return bb_full_fd_action(fd1, fd2, 0);
}