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/* vi: set sw=4 ts=4: */
/*
* Utility routines.
*
* Copyright (C) 1999-2004 by Erik Andersen <andersen@codepoet.org>
*
* Licensed under GPLv2 or later, see file LICENSE in this source tree.
*/
#include "libbb.h"
ssize_t FAST_FUNC safe_read(int fd, void *buf, size_t count)
{
ssize_t n;
for (;;) {
n = read(fd, buf, count);
if (n >= 0 || errno != EINTR)
break;
/* Some callers set errno=0, are upset when they see EINTR.
* Returning EINTR is wrong since we retry read(),
* the "error" was transient.
*/
errno = 0;
/* repeat the read() */
}
return n;
}
/*
* 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.
*/
ssize_t FAST_FUNC full_read(int fd, void *buf, size_t len)
{
ssize_t cc;
ssize_t total;
total = 0;
while (len) {
cc = safe_read(fd, buf, len);
if (cc < 0) {
if (total) {
/* we already have some! */
/* user can do another read to know the error code */
return total;
}
return cc; /* read() returns -1 on failure. */
}
if (cc == 0)
break;
buf = ((char *)buf) + cc;
total += cc;
len -= cc;
}
return total;
}
ssize_t FAST_FUNC read_close(int fd, void *buf, size_t size)
{
/*int e;*/
size = full_read(fd, buf, size);
/*e = errno;*/
close(fd);
/*errno = e;*/
return size;
}
ssize_t FAST_FUNC open_read_close(const char *filename, void *buf, size_t size)
{
int fd = open(filename, O_RDONLY);
if (fd < 0)
return fd;
return read_close(fd, buf, size);
}
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