3fc4ad1478
chunk of data when they get it and not block until they've buffered 4k. The use case was cat /proc/psaux, but you can also reproduce this by running non-busybox cat by itself and typing things at the command line. Then run busybox cat. Notice how cat is _supposed_ to echo each line back to us as we hit enter?
75 lines
1.4 KiB
C
75 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 "busybox.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 wrote, xread = (size && size < BUFSIZ) ? size : BUFSIZ;
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xread = safe_read(src_fd, buffer, xread);
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if (xread > 0) {
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/* A -1 dst_fd means we need to fake it... */
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wrote = (dst_fd < 0) ? xread : bb_full_write(dst_fd, buffer, xread);
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if (wrote < xread) {
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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 += wrote;
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size -= wrote;
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} else if (xread < 0) {
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bb_perror_msg(bb_msg_read_error);
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break;
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} else if (xread == 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 : total;
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}
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extern 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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extern 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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