asprintf(3) [x11r4 man page]

ASPRINTF(3)						     Linux Programmer's Manual						       ASPRINTF(3)

NAME

       asprintf, vasprintf - print to allocated string

SYNOPSIS

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

       int asprintf(char **strp, const char *fmt, ...);

       int vasprintf(char **strp, const char *fmt, va_list ap);

DESCRIPTION

       The functions asprintf() and vasprintf() are analogs of sprintf(3) and vsprintf(3), except that they allocate a string large enough to hold
       the output including the terminating null byte (''), and return a pointer to it via the first argument.  This pointer should be passed to
       free(3) to release the allocated storage when it is no longer needed.

RETURN VALUE

       When  successful,  these functions return the number of bytes printed, just like sprintf(3).  If memory allocation wasn't possible, or some
       other error occurs, these functions will return -1, and the contents of strp are undefined.

ATTRIBUTES

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

       +------------------------+---------------+----------------+
       |Interface		| Attribute	| Value 	 |
       +------------------------+---------------+----------------+
       |asprintf(), vasprintf() | Thread safety | MT-Safe locale |
       +------------------------+---------------+----------------+

CONFORMING TO

       These functions are GNU extensions, not in C or POSIX.  They are also available under *BSD.  The FreeBSD implementation sets strp  to  NULL
       on error.

SEE ALSO

       free(3), malloc(3), printf(3)

COLOPHON

       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU
								    2017-09-15							       ASPRINTF(3)

STRDUP(3)						     Linux Programmer's Manual							 STRDUP(3)

NAME

       strdup, strndup, strdupa, strndupa - duplicate a string

SYNOPSIS

       #include <string.h>

       char *strdup(const char *s);

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

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

       strdup():
	   _XOPEN_SOURCE >= 500
	       || /* Since glibc 2.12: */ _POSIX_C_SOURCE >= 200809L
	       || /* Glibc versions <= 2.19: */ _BSD_SOURCE || _SVID_SOURCE
       strndup():
	   Since glibc 2.10:
	       _POSIX_C_SOURCE >= 200809L
	   Before glibc 2.10:
	       _GNU_SOURCE
       strdupa(), strndupa(): _GNU_SOURCE

DESCRIPTION

       The  strdup()  function returns a pointer to a new string which is a duplicate of the string s.	Memory for the new string is obtained with
       malloc(3), and can be freed with free(3).

       The strndup() function is similar, but copies at most n bytes.  If s is longer than n, only n bytes are copied, and a terminating null byte
       ('') is added.

       strdupa()  and strndupa() are similar, but use alloca(3) to allocate the buffer.  They are available only when using the GNU GCC suite, and
       suffer from the same limitations described in alloca(3).

RETURN VALUE

       On success, the strdup() function returns a pointer to the duplicated string.  It returns NULL if insufficient memory was  available,  with
       errno set to indicate the cause of the error.

ERRORS

       ENOMEM Insufficient memory available to allocate duplicate string.

ATTRIBUTES

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

       +--------------------------------+---------------+---------+
       |Interface			| Attribute	| Value   |
       +--------------------------------+---------------+---------+
       |strdup(), strndup(), strdupa(), | Thread safety | MT-Safe |
       |strndupa()			|		|	  |
       +--------------------------------+---------------+---------+

CONFORMING TO

       strdup() conforms to SVr4, 4.3BSD, POSIX.1-2001.  strndup() conforms to POSIX.1-2008.  strdupa() and strndupa() are GNU extensions.

SEE ALSO

       alloca(3), calloc(3), free(3), malloc(3), realloc(3), string(3), wcsdup(3)

COLOPHON

       This  page is part of release 4.15 of the Linux man-pages project.  A description of the project, information about reporting bugs, and the
       latest version of this page, can be found at https://www.kernel.org/doc/man-pages/.

GNU
								    2017-09-15								 STRDUP(3)