---
name: "mmap_read"
section: "3"
platform: "linux"
package: "libowfat-dev"
version: "0.32-5"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/mmap_read"
---

# mmap\_read(3)

memory map a file for reading

## NAME

mmap\_read - memory map a file for reading

## SYNTAX

**#include \<libowfat/mmap.h\>**

const char\* **mmap\_read**(const char\* *filename*,size\_t\* *filesize*);

## DESCRIPTION

mmap\_read opens *filename* for reading, maps the whole file into memory, closes the file, writes the length of the file to *filesize* and returns a pointer to the mapped file.

The file is unmapped by the operating system if the process terminates. It can also be manually unmapped by calling **munmap** from \<sys/mman.h\>.

If the file could not be opened or mapped, (void\*)0 is returned.

## SEE ALSO

[mmap\_unmap(3)](/mmap_unmap/3.md)