---
name: "nng_strdup"
section: "3"
platform: "linux"
package: "libnng-dev"
version: "1.10.1-2"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/nng_strdup"
---

# nng\_strdup(3)

duplicate string

## NAME

nng\_strdup - duplicate string

## SYNOPSIS

```
#include <nng/nng.h>
char *nng_strdup(const char *src);
```

## DESCRIPTION

The `nng_strdup()` duplicates the string *src* and returns it.

This is logically equivalent to using `nng_alloc()` to allocate a region of memory of `strlen(s) + 1` bytes, and then using `strcpy()` to copy the string into the destination before returning it.

The returned string should be deallocated with `nng_strfree()`, or may be deallocated using the `nng_free()` using the length of the returned string plus one (for the `NUL` terminating byte).

**Important**\

Do not use the system `free()` or similar functions to deallocate the string, since those may use a different memory arena!

## RETURN VALUES

This function returns the new string on success, and `NULL` on failure.

## ERRORS

No errors are returned, but a `NULL` return value should be treated the same as `NNG_ENOMEM`.

## SEE ALSO

[nng\_alloc(3)](/nng_alloc/3.md), [nng\_free(3)](/nng_free/3.md), [nng(7)](/nng/7.md)