[#BloombergLP-bdls-FilesystemUtil-mapChecked]
= xref:BloombergLP.adoc[BloombergLP]::xref:BloombergLP/bdls.adoc[bdls]::xref:BloombergLP/bdls/FilesystemUtil.adoc[FilesystemUtil]::mapChecked
:relfileprefix: ../../../
:mrdocs:

Map the region of the specified `size` bytes, starting at the specified `offset` bytes into the file with the specified `descriptor` to memory, and load into the specified `address` of the mapped area. Return 0 on success, `k_ERROR_PAST_EOF` if an attempt is made to map past the end of file, and a non‐zero value otherwise. The access permissions for mapping memory are defined by the specified `mode`, which may be a combination of `MemoryUtil::k_ACCESS_READ`, `MemoryUtil::k_ACCESS_WRITE` and `MemoryUtil::k_ACCESS_EXECUTE`, though on some platforms they must be a subset of the file permissions. The behavior is undefined unless bits in `mode` other than `MemoryUtil::k_ACCESS_READ_WRITE_EXECUTE` are all clear, unless `0 <= offset`, and unless `0 < size`, and unless the `offset` is a multiple of `MemoryUtil::pageSize()`. Note that on failure, the value of `address` is undefined. Also note that the check against mapping past the end of file and all assertions are done before the call to map the file.

== Synopsis

Declared in `<bdls_filesystemutil.h>`

[source,cpp,subs="verbatim,replacements,macros,-callouts"]
----
static
int
mapChecked(
    xref:BloombergLP/bdls/FilesystemUtil/FileDescriptor.adoc[FileDescriptor] descriptor,
    void** address,
    xref:BloombergLP/bdls/FilesystemUtil/Offset.adoc[Offset] offset,
    std::size_t size,
    int mode);
----


[.small]#Created with https://www.mrdocs.com[MrDocs]#