'\" t
.\" Copyright, the authors of the Linux man-pages project
.\"
.\" SPDX-License-Identifier: Linux-man-pages-copyleft
.\"
.TH stpncpy 3 2026-08-10 "Linux man-pages 6.19"
.SH NAME
stpncpy \- nonstring return‐offset‐pointer copy
.SH LIBRARY
Standard C library
.RI ( libc ,\~ \-lc )
.SH SYNOPSIS
.nf
.BR #include\~<string.h> "  // see memory.h(3head)"
.P
.BR "char *stpncpy(" "size_t dsize;"
.BI "              char " dst "[restrict " dsize "], const char *restrict " src ,
.BI "              size_t " dsize );
.fi
.P
.RS -4
Feature Test Macro Requirements for glibc (see
.BR feature_test_macros (7)):
.RE
.P
.BR stpncpy ():
.nf
    Since glibc 2.10:
        _POSIX_C_SOURCE >= 200809L
    Before glibc 2.10:
        _GNU_SOURCE
.fi
.SH DESCRIPTION
This function is equivalent to
.BR strncpy (3),
but it returns a pointer to
one past the last nonnull written character.
.P
It is equivalent to
.P
.in +4n
.EX
memset(mempcpy(dst, src, strnlen(src, dsize)), \[aq]\[rs]0\[aq],
       dsize \- strnlen(src, dsize))
.EE
.in
.SH RETURN VALUE
This function returns
a pointer to
one past the last non-null character written,
that is,
.IR dest\~+\~strnlen(src,\~n) .
.SH ATTRIBUTES
For an explanation of the terms used in this section, see
.BR attributes (7).
.TS
allbox;
lbx lb lb
l l l.
Interface	Attribute	Value
T{
.na
.nh
.BR stpncpy ()
T}	Thread safety	MT-Safe
.TE
.SH STANDARDS
POSIX.1-2008.
.SH HISTORY
glibc 1.07.
POSIX.1-2008.
.SH CAVEATS
See
.BR strncpy (3).
.SH SEE ALSO
.BR memory.h (3head),
.BR string_copying (7)