---
name: "strncpy_from_user"
section: "9"
platform: "linux"
package: "linux-manual-3.2"
version: "3.2.78-1"
release: "Debian 7 (Wheezy)"
platforms: ["linux"]
url: "https://new.carta.tech/strncpy_from_user"
---

# strncpy\_from\_user(9)

Copy a NUL terminated string from userspace.

## NAME

strncpy\_from\_user - Copy a NUL terminated string from userspace.

## SYNOPSIS

**long strncpy\_from\_user(char \*** *dst***, const char \_\_user \*** *src***, long** *count***);**

## ARGUMENTS

*dst*

Destination address, in kernel space. This buffer must be at least *count* bytes long.

*src*

Source address, in user space.

*count*

Maximum number of bytes to copy, including the trailing NUL.

## DESCRIPTION

Copies a NUL-terminated string from userspace to kernel space.

On success, returns the length of the string (not including the trailing NUL).

If access to userspace fails, returns -EFAULT (some data may have been copied).

If *count* is smaller than the length of the string, copies *count* bytes and returns *count*.

## COPYRIGHT