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

# stpncpy(3)

nonstring return‐offset‐pointer copy

## NAME

stpncpy - nonstring return‐offset‐pointer copy

## LIBRARY

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

## SYNOPSIS

```
#include <string.h>  // see memory.h(3head)
```

**char \*stpncpy(**size\_t dsize;               **char** *dst***\[restrict** *dsize***\], const char \*restrict** *src***,**               **size\_t** *dsize***);**

Feature Test Macro Requirements for glibc (see [**feature\_test\_macros**(7)](/feature_test_macros/7.md)):

**stpncpy**():

```
    Since glibc 2.10:
        _POSIX_C_SOURCE >= 200809L
    Before glibc 2.10:
        _GNU_SOURCE
```

## DESCRIPTION

This function is equivalent to [**strncpy**(3)](/strncpy/3.md), but it returns a pointer to one past the last nonnull written character.

It is equivalent to

```
memset(mempcpy(dst, src, strnlen(src, dsize)), '\0',
       dsize - strnlen(src, dsize))
```

## RETURN VALUE

This function returns a pointer to one past the last non-null character written, that is, *dest + strnlen(src, n)*.

## ATTRIBUTES

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

| | | |
| --- | --- | --- |
| **Interface** | **Attribute** | **Value** |
| **stpncpy**() | Thread safety | MT-Safe |

## STANDARDS

POSIX.1-2008.

## HISTORY

glibc 1.07. POSIX.1-2008.

## CAVEATS

See [**strncpy**(3)](/strncpy/3.md).

## SEE ALSO

[**memory.h**(3head)](/memory.h/3head.md), [**string\_copying**(7)](/string_copying/7.md)