stpcpy(3)                  Library Functions Manual                  stpcpy(3)

NAME
       stpcpy - string return-offset-pointer copy

LIBRARY
       Standard C library (libc, -lc)

SYNOPSIS
       #include <string.h>

       char *stpcpy(char *restrict dst, const char *restrict src);

   Feature Test Macro Requirements for glibc (see feature_test_macros(7)):

       stpcpy():
           Since glibc 2.10:
               _POSIX_C_SOURCE >= 200809L
           Before glibc 2.10:
               _GNU_SOURCE

DESCRIPTION
       stpcpy() is similar to strcpy(3), but returns a pointer to the
       terminating null byte in dst.

       It is equivalent to all of the following expressions:

           memset(mempcpy(dst, src, strlen(src)), '\0', 1);
           strcpy(mempcpy(dst, src, strlen(src)), "");
           strcpy(dst, src) + strlen(src)

RETURN VALUE
       This function returns a pointer to the terminating null byte of the
       copied string.

ATTRIBUTES
       For an explanation of the terms used in this section, see
       attributes(7).

       +--------------------------------------------+---------------+---------+
       |Interface                                   | Attribute     | Value   |
       +--------------------------------------------+---------------+---------+
       |stpcpy ()                                   | Thread safety | MT-Safe |
       +--------------------------------------------+---------------+---------+
STANDARDS
       POSIX.1-2008.

HISTORY
       POSIX.1-2008.

EXAMPLES
       #include <err.h>
       #include <stdio.h>
       #include <stdlib.h>
       #include <string.h>

       int
       main(void)
       {
           char    *p;
           char    *buf1;
           size_t  len, size;

           size = strlen("Hello ") + strlen("world") + strlen("!") + 1;
           buf1 = malloc(sizeof(*buf1) * size);
           if (buf1 == NULL)
               err(EXIT_FAILURE, "malloc()");

           p = buf1;
           p = stpcpy(p, "Hello ");
           p = stpcpy(p, "world");
           p = stpcpy(p, "!");
           len = p - buf1;

           printf("[len = %zu]: ", len);
           puts(buf1);  // "Hello world!"
           free(buf1);

           exit(EXIT_SUCCESS);
       }

SEE ALSO
       strcpy(3), string(3), wcpcpy(3), string_copying(7)

Linux man-pages 6.19              2026-08-10                         stpcpy(3)