.\" Automatically generated by Pandoc 2.0.6
.\"
.TH "PMEM2_SOURCE_SIZE" "3" "2022-08-25" "PMDK - pmem2 API version 1.0" "PMDK Programmer's Manual"
.hy
.\" SPDX-License-Identifier: BSD-3-Clause
.\" Copyright 2019-2021, Intel Corporation
.SH NAME
.PP
\f[B]pmem2_source_size\f[]() \- returns the size of the data source
.SH SYNOPSIS
.IP
.nf
\f[C]
#include\ <libpmem2.h>

struct\ pmem2_source;
int\ pmem2_source_size(const\ struct\ pmem2_source\ *source,\ size_t\ *size);
\f[]
.fi
.SH DESCRIPTION
.PP
The \f[B]pmem2_source_size\f[]() function retrieves the size of the file
in bytes pointed by file descriptor or handle stored in the
\f[I]source\f[] and puts it in \f[I]*size\f[].
.PP
This function is a portable replacement for OS\-specific APIs.
On Linux, it hides the quirkiness of Device DAX size detection.
.SH RETURN VALUE
.PP
The \f[B]pmem2_source_size\f[]() function returns 0 on success.
If the function fails, the \f[I]*size\f[] variable is left unmodified
and a negative error code is returned.
.SH ERRORS
.PP
The \f[B]pmem2_source_size\f[]() can fail with the following errors:
.PP
On all systems:
.IP \[bu] 2
\f[B]PMEM2_E_INVALID_FILE_HANDLE\f[] \- source contains an invalid file
handle.
.PP
On Windows:
.IP \[bu] 2
\f[B]PMEM2_E_INVALID_FILE_TYPE\f[] \- handle points to a resource that
is not a regular file.
.PP
On Linux:
.IP \[bu] 2
\f[B]PMEM2_E_INVALID_FILE_TYPE\f[] \- file descriptor points to a
directory, block device, pipe, or socket.
.IP \[bu] 2
\f[B]PMEM2_E_INVALID_FILE_TYPE\f[] \- file descriptor points to a
character device other than Device DAX.
.IP \[bu] 2
\f[B]PMEM2_E_INVALID_SIZE_FORMAT\f[] \- kernel query for Device DAX size
returned data in invalid format.
.IP \[bu] 2
\-\f[B]errno\f[] set by failing \f[B]fstat\f[](2), while trying to
validate the file descriptor.
.IP \[bu] 2
\-\f[B]errno\f[] set by failing \f[B]realpath\f[](3), while trying to
determine whether fd points to a Device DAX.
.IP \[bu] 2
\-\f[B]errno\f[] set by failing \f[B]open\f[](2), while trying to
determine Device DAX's size.
.IP \[bu] 2
\-\f[B]errno\f[] set by failing \f[B]read\f[](2), while trying to
determine Device DAX's size.
.IP \[bu] 2
\-\f[B]errno\f[] set by failing \f[B]strtoull\f[](3), while trying to
determine Device DAX's size.
.PP
On FreeBSD:
.IP \[bu] 2
\f[B]PMEM2_E_INVALID_FILE_TYPE\f[] \- file descriptor points to a
directory, block device, pipe, socket, or character device.
.IP \[bu] 2
\-\f[B]errno\f[] set by failing \f[B]fstat\f[](2), while trying to
validate the file descriptor.
.SH SEE ALSO
.PP
\f[B]errno\f[](3), \f[B]fstat\f[](2), \f[B]realpath\f[](3),
\f[B]open\f[](2), \f[B]read\f[](2), \f[B]strtoull\f[](3),
\f[B]pmem2_config_new\f[](3), \f[B]libpmem2\f[](7) and
\f[B]<https://pmem.io>\f[]