strdupa(3) — Linux manual page

strdupa(3)               Library Functions Manual              strdupa(3)

NAME         top

       strdupa, strndupa - string duplicate using alloca

LIBRARY         top

       Standard C library (libc, -lc)

SYNOPSIS         top

       #define _GNU_SOURCE  /* See feature_test_macros(7) */
       #include <string.h>

       char *strdupa(const char *s);
       char *strndupa(size_t n;
                     const char s[n], size_t n);

DESCRIPTION         top

       strdupa()
              strdupa() is similar to strdup(3), but uses alloca(3) to
              allocate the buffer.

              It is equivalent to

                  strcpy(alloca(strlen(s) + 1), s)

       strndupa()
              strndupa() is similar to strndupa(3), but uses alloca(3) to
              allocate the buffer.

              It is equivalent to

                  strncat(strcpy(alloca(n + 1), ""), s, n)

RETURN VALUE         top

       On success, these macros return a pointer to the duplicated
       string.

ATTRIBUTES         top

       For an explanation of the terms used in this section, see
       attributes(7).
       ┌──────────────────────────────────────┬───────────────┬─────────┐
       │ Interface                            │ Attribute     │ Value   │
       ├──────────────────────────────────────┼───────────────┼─────────┤
       │ strdupa(), strndupa()                │ Thread safety │ MT-Safe │
       └──────────────────────────────────────┴───────────────┴─────────┘

STANDARDS         top

       GNU.

HISTORY         top

       GNU.

SEE ALSO         top

       alloca(3), strdup(3), strndup(3)

COLOPHON         top

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Linux man-pages 6.18            2026-02-25                     strdupa(3)

Pages that refer to this page: alloca(3),  strdup(3),  strdupa(3)

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