busybox/libbb/full_read.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 <stdio.h>
#include <unistd.h>
#include "libbb.h"
/*
* Read all of the supplied buffer from a file.
* This does multiple reads as necessary.
* Returns the amount read, or -1 on an error.
* A short read is returned on an end of file.
*/
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ssize_t bb_full_read(int fd, void *buf, size_t len)
{
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ssize_t cc;
ssize_t total;
total = 0;
while (len > 0) {
cc = read(fd, buf, len);
if (cc < 0)
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return cc; /* read() returns -1 on failure. */
if (cc == 0)
break;
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buf = ((char *)buf) + cc;
total += cc;
len -= cc;
}
return total;
}
/* END CODE */
/*
Local Variables:
c-file-style: "linux"
c-basic-offset: 4
tab-width: 4
End:
*/