MANDOC_MALLOC(3) BSD Library Functions Manual MANDOC_MALLOC(3)NAME
mandoc_malloc, mandoc_realloc, mandoc_reallocarray, mandoc_calloc,
mandoc_strdup, mandoc_strndup, mandoc_asprintf — memory allocation func‐
tion wrappers used in the mandoc library
LIBRARY
library “libmandoc”
SYNOPSIS
#include <sys/types.h>
#include <mandoc_aux.h>
void *
mandoc_malloc(size_t size);
void *
mandoc_realloc(void *ptr, size_t size);
void *
mandoc_reallocarray(void *ptr, size_t nmemb, size_t size);
void *
mandoc_calloc(size_t nmemb, size_t size);
char *
mandoc_strdup(const char *s);
char *
mandoc_strndup(const char *s, size_t maxlen);
int
mandoc_asprintf(char **ret, const char *format, ...);
DESCRIPTION
These functions call the Standard C Library (libc, -lc) functions of the
same names, passing through their return values when successful. In case
of failure, they do not return, but instead call perror(3) and exit(3).
They can be used both internally by any code in the library “libmandoc”
and externally by programs using that library, for example mandoc(1),
apropos(1), and makewhatis(8).
The function mandoc_malloc() allocates one new object, leaving the memory
uninitialized. The functions mandoc_realloc() and mandoc_reallocarray()
change the size of an existing object or array, possibly moving it. When
shrinking the size, existing data is truncated; when growing, the addi‐
tional memory is not initialized. The function mandoc_calloc() allocates
a new array, initializing it to zero.
The argument size is the size of each object. The argument nmemb is the
new number of objects in the array. The argument ptr is a pointer to the
existing object or array to be resized; if it is NULL, a new object or
array is allocated.
The functions mandoc_strdup() and mandoc_strndup() copy a string into
newly allocated memory. For mandoc_strdup(), the string pointed to by s
needs to be NUL-terminated. For mandoc_strndup(), at most maxlen bytes
are copied. The function mandoc_asprintf() writes output formatted
according to format into newly allocated memory and returns a pointer to
the result in ret. For all three string functions, the result is always
NUL-terminated.
When the objects and strings are no longer needed, the pointers returned
by these functions can be passed to free(3).
RETURN VALUES
The function mandoc_asprintf() always returns the number of characters
written, excluding the final NUL byte. It never returns -1.
The other functions always return a valid pointer; they never return
NULL.
FILES
These functions are implemented in mandoc_aux.c.
SEE ALSOasprintf(3), exit(3), malloc(3), perror(3), strdup(3)STANDARDS
The functions malloc(), realloc(), and calloc() are required by ANSI
X3.159-1989 (“ANSI C89”). The functions strdup() and strndup() are
required by IEEE Std 1003.1-2008 (“POSIX.1”). The function asprintf() is
a widespread extension that first appeared in the GNU C library.
The function reallocarray() is an extension that first appeared in
OpenBSD 5.6. If it is not provided by the operating system, the mandoc
build system uses a bundled portable implementation.
HISTORY
The functions mandoc_malloc(), mandoc_realloc(), mandoc_calloc(), and
mandoc_strdup() have been available since mandoc 1.9.12, mandoc_strndup()
since 1.11.5, and mandoc_asprintf() and mandoc_reallocarray() since
1.12.4 and 1.13.0.
AUTHORS
Kristaps Dzonsons ⟨kristaps@bsd.lv⟩
Ingo Schwarze ⟨schwarze@openbsd.org⟩
BSD April 28, 2024 BSD
