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BUF_strdup and friends: update docs

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Reviewed-by: Matt Caswell <matt@openssl.org>
(cherry picked from commit 58e3457a82e8940ff36b36949f9c7a60e7614b2c)
(cherry picked from commit be250ee2d353a9c8ed858bf8ca274d3107ae2f64)
This commit is contained in:
Emilia Kasper 2015-09-17 13:50:34 +02:00
parent e56c77b8ee
commit 456b9820eb
1 changed files with 24 additions and 23 deletions
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47
doc/crypto/buffer.pod
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@ -2,8 +2,11 @@
=head1 NAME =head1 NAME
BUF_MEM_new, BUF_MEM_free, BUF_MEM_grow, BUF_strdup - simple BUF_MEM_new, BUF_MEM_new_ex, BUF_MEM_free, BUF_MEM_grow - simple
character arrays structure character array structure
BUF_strdup, BUF_strndup, BUF_memdup, BUF_strlcpy, BUF_strlcat -
standard C library equivalents
=head1 SYNOPSIS =head1 SYNOPSIS
@ -15,26 +18,21 @@ character arrays structure
int BUF_MEM_grow(BUF_MEM *str, int len); int BUF_MEM_grow(BUF_MEM *str, int len);
char * BUF_strdup(const char *str); char *BUF_strdup(const char *str);
char *BUF_strndup(const char *str, size_t siz);
void *BUF_memdup(const void *data, size_t siz);
size_t BUF_strlcpy(char *dst, const char *src, size_t size);
size_t BUF_strlcat(char *dst, const char *src, size_t size);
=head1 DESCRIPTION =head1 DESCRIPTION
The buffer library handles simple character arrays. Buffers are used for The buffer library handles simple character arrays. Buffers are used for
various purposes in the library, most notably memory BIOs. various purposes in the library, most notably memory BIOs.
The library uses the BUF_MEM structure defined in buffer.h:
typedef struct buf_mem_st
{
int length; /* current number of bytes */
char *data;
int max; /* size of buffer */
} BUF_MEM;
B<length> is the current size of the buffer in bytes, B<max> is the amount of
memory allocated to the buffer. There are three functions which handle these
and one "miscellaneous" function.
BUF_MEM_new() allocates a new buffer of zero size. BUF_MEM_new() allocates a new buffer of zero size.
BUF_MEM_free() frees up an already existing buffer. The data is zeroed BUF_MEM_free() frees up an already existing buffer. The data is zeroed
@ -44,14 +42,17 @@ BUF_MEM_grow() changes the size of an already existing buffer to
B<len>. Any data already in the buffer is preserved if it increases in B<len>. Any data already in the buffer is preserved if it increases in
size. size.
BUF_strdup() copies a null terminated string into a block of allocated BUF_strdup(), BUF_strndup(), BUF_memdup(), BUF_strlcpy() and
memory and returns a pointer to the allocated block. BUF_strlcat() are equivalents of the standard C library functions. The
Unlike the standard C library strdup() this function uses OPENSSL_malloc() and so dup() functions use OPENSSL_malloc() underneath and so should be used
should be used in preference to the standard library strdup() because it can in preference to the standard library for memory leak checking or
be used for memory leak checking or replacing the malloc() function. replacing the malloc() function.
The memory allocated from BUF_strdup() should be freed up using the OPENSSL_free() Memory allocated from these functions should be freed up using the
function. OPENSSL_free() function.
BUF_strndup makes the explicit guarantee that it will never read past
the first B<siz> bytes of B<str>.
=head1 RETURN VALUES =head1 RETURN VALUES