---
name: "pmem2_config_set_length"
section: "3"
platform: "linux"
package: "libpmem2-dev"
version: "1.13.1-1.1+b1"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/pmem2_config_set_length"
---

# pmem2\_config\_set\_length(3)

set length in the pmem2\_config structure

## NAME

**pmem2\_config\_set\_length**() - set length in the pmem2\_config structure

## SYNOPSIS

-

  ```
  #include <libpmem2.h>
  struct pmem2_config;
  int pmem2_config_set_length(struct pmem2_config *config, size_t length);
  ```

## DESCRIPTION

The **pmem2\_config\_set\_length**() function configures the length which will be used for mapping. *\*config* should be already initialized, please see [**pmem2\_config\_new**(3)](/pmem2_config_new/3.md) for details. The *must be a multiple of the alignment required for the data* *source which will be used for mapping alongside the config. To retrieve* *the alignment required for specific instance of* pmem2\_source\*\* use [**pmem2\_source\_alignment**(3)](/pmem2_source_alignment/3.md). By default, the length is equal to the size of the file that is being mapped.

## RETURN VALUE

The **pmem2\_config\_set\_length**() function always returns 0.

## SEE ALSO

[**libpmem2**(7)](/libpmem2/7.md), [**pmem2\_map\_new**(3)](/pmem2_map_new/3.md), [**pmem2\_source\_alignment**(3)](/pmem2_source_alignment/3.md), [**pmem2\_config\_new**(3)](/pmem2_config_new/3.md), [**sysconf**(3)](/sysconf/3.md) and **\<https://pmem.io\>**