busybox/libbb/copyfd.c

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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999,2000,2001 by Erik Andersen <andersee@debian.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#include <unistd.h>
#include <string.h>
#include <errno.h>
#include "libbb.h"
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/* If chunksize is 0 copy untill EOF */
extern int copyfd(int fd1, int fd2, const off_t chunksize)
{
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size_t nread;
size_t nwritten;
size_t size;
size_t remaining;
char buffer[BUFSIZ];
if (chunksize) {
remaining = chunksize;
} else {
remaining = -1;
}
do {
if ((chunksize > BUFSIZ) || (chunksize == 0)) {
size = BUFSIZ;
} else {
size = chunksize;
}
nread = safe_read(fd1, buffer, size);
if (nread == -1) {
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perror_msg("read failure");
return(-1);
}
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else if (nread == 0) {
if (chunksize) {
error_msg("Unable to read all data");
return(-1);
} else {
return(0);
}
}
nwritten = full_write(fd2, buffer, nread);
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if (nwritten != nread) {
error_msg("Unable to write all data");
return(-1);
}
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if (chunksize) {
remaining -= nwritten;
}
} while (remaining != 0);
return 0;
}
/* END CODE */
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/