---
name: "get_nprocs"
section: "3"
platform: "linux"
package: "man-pages"
version: "6.19-1"
release: "Arch Linux 2026-11-01"
platforms: ["linux"]
url: "https://new.carta.tech/get_nprocs"
---

# get\_nprocs(3)

get number of processors

## NAME

get\_nprocs, get\_nprocs\_conf - get number of processors

## LIBRARY

Standard C library (*libc*, *-lc*)

## SYNOPSIS

```
#include <sys/sysinfo.h>
```

**int get\_nprocs(void);** **int get\_nprocs\_conf(void);**

## DESCRIPTION

The function **get\_nprocs\_conf**() returns the number of processors configured by the operating system.

The function **get\_nprocs**() returns the number of processors currently available in the system. This may be less than the number returned by **get\_nprocs\_conf**() because processors may be offline (e.g., on hotpluggable systems).

## RETURN VALUE

As given in DESCRIPTION.

## ATTRIBUTES

For an explanation of the terms used in this section, see [**attributes**(7)](/attributes/7.md).

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **get\_nprocs**(), **get\_nprocs\_conf**() | Thread safety | MT-Safe |

## STANDARDS

GNU.

## NOTES

The current implementation of these functions is rather expensive, since they open and parse files in the */sys* filesystem each time they are called.

The following [**sysconf**(3)](/sysconf/3.md) calls make use of the functions documented on this page to return the same information.

```
np = sysconf(_SC_NPROCESSORS_CONF);     /* processors configured */
np = sysconf(_SC_NPROCESSORS_ONLN);     /* processors available */
```

## EXAMPLES

The following example shows how **get\_nprocs**() and **get\_nprocs\_conf**() can be used.

```
#include <stdio.h>
#include <stdlib.h>
#include <sys/sysinfo.h>
int
main(void)
{
    printf("This system has %d processors configured and "
            "%d processors available.\n",
            get_nprocs_conf(), get_nprocs());
    exit(EXIT_SUCCESS);
}
```

## SEE ALSO

[**nproc**(1)](/nproc/1.md)