busybox/libbb/copyfd.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;

	if (!size) {
		size = BUFSIZ;
		status = 1; /* copy until eof */
	}

	while (1) {
		ssize_t rd;

		rd = safe_read(src_fd, buffer, size > BUFSIZ ? BUFSIZ : 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:
	RELEASE_CONFIG_BUFFER(buffer);
	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 */
	exit(xfunc_error_retval);
}
#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 */
	exit(xfunc_error_retval);
}

off_t bb_copyfd_eof(int fd1, int fd2)
{
	return bb_full_fd_action(fd1, fd2, 0);
}
1	/* vi: set sw=4 ts=4: */
2	/*
3	* Utility routines.
4	*
5	* Copyright (C) 1999-2005 by Erik Andersen <andersen@codepoet.org>
6	*
7	* Licensed under GPLv2 or later, see file LICENSE in this tarball for details.
8	*/
9
10	#include <errno.h>
11	#include <stdlib.h>
12	#include <string.h>
13	#include <unistd.h>
14
15	#include "libbb.h"
16
17
18	#if BUFSIZ < 4096
19	#undef BUFSIZ
20	#define BUFSIZ 4096
21	#endif
22
23
24	static off_t bb_full_fd_action(int src_fd, int dst_fd, off_t size)
25	{
26	int status = -1;
27	off_t total = 0;
28	RESERVE_CONFIG_BUFFER(buffer, BUFSIZ);
29
30	if (src_fd < 0) goto out;
31
32	if (!size) {
33	size = BUFSIZ;
34	status = 1; /* copy until eof */
35	}
36
37	while (1) {
38	ssize_t rd;
39
40	rd = safe_read(src_fd, buffer, size > BUFSIZ ? BUFSIZ : size);
41
42	if (!rd) { /* eof - all done */
43	status = 0;
44	break;
45	}
46	if (rd < 0) {
47	bb_perror_msg(bb_msg_read_error);
48	break;
49	}
50	/* dst_fd == -1 is a fake, else... */
51	if (dst_fd >= 0) {
52	ssize_t wr = full_write(dst_fd, buffer, rd);
53	if (wr < rd) {
54	bb_perror_msg(bb_msg_write_error);
55	break;
56	}
57	}
58	total += rd;
59	if (status < 0) { /* if we aren't copying till EOF... */
60	size -= rd;
61	if (!size) {
62	/* 'size' bytes copied - all done */
63	status = 0;
64	break;
65	}
66	}
67	}
68	out:
69	RELEASE_CONFIG_BUFFER(buffer);
70	return status ? -1 : total;
71	}
72
73
74	#if 0
75	void complain_copyfd_and_die(off_t sz)
76	{
77	if (sz != -1)
78	bb_error_msg_and_die("short read");
79	/* if sz == -1, bb_copyfd_XX already complained */
80	exit(xfunc_error_retval);
81	}
82	#endif
83
84	off_t bb_copyfd_size(int fd1, int fd2, off_t size)
85	{
86	if (size) {
87	return bb_full_fd_action(fd1, fd2, size);
88	}
89	return 0;
90	}
91
92	void bb_copyfd_exact_size(int fd1, int fd2, off_t size)
93	{
94	off_t sz = bb_copyfd_size(fd1, fd2, size);
95	if (sz == size)
96	return;
97	if (sz != -1)
98	bb_error_msg_and_die("short read");
99	/* if sz == -1, bb_copyfd_XX already complained */
100	exit(xfunc_error_retval);
101	}
102
103	off_t bb_copyfd_eof(int fd1, int fd2)
104	{
105	return bb_full_fd_action(fd1, fd2, 0);
106	}