buffer(3)                   OpenSSL                   buffer(3)





NAME
       BUF_MEM_new, BUF_MEM_free, BUF_MEM_grow, BUF_strdup -
       simple character arrays structure

SYNOPSIS
        #include <openssl/buffer.h>

        BUF_MEM *BUF_MEM_new(void);

        void   BUF_MEM_free(BUF_MEM *a);

        int    BUF_MEM_grow(BUF_MEM *str, int len);

        char * BUF_strdup(const char *str);

DESCRIPTION
       The buffer library handles simple character arrays.
       Buffers are used for 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;

       length is the current size of the buffer in bytes, max
       is the amount of memory allocated to the buffer. There
       are three functions which handle these and one "miscel-
       laneous" function.

       BUF_MEM_new() allocates a new buffer of zero size.

       BUF_MEM_free() frees up an already existing buffer. The
       data is zeroed before freeing up in case the buffer con-
       tains sensitive data.

       BUF_MEM_grow() changes the size of an already existing
       buffer to len. Any data already in the buffer is pre-
       served if it increases in size.

       BUF_strdup() copies a null terminated string into a
       block of allocated memory and returns a pointer to the
       allocated block.  Unlike the standard C library strdup()
       this function uses OPENSSL_malloc() and so should be
       used in preference to the standard library strdup()
       because it can be used for memory leak checking or
       replacing the malloc() function.

       The memory allocated from BUF_strdup() should be freed
       up using the OPENSSL_free() function.

RETURN VALUES
       BUF_MEM_new() returns the buffer or NULL on error.

       BUF_MEM_free() has no return value.

       BUF_MEM_grow() returns zero on error or the new size
       (i.e. len).

SEE ALSO
       bio(3)

HISTORY
       BUF_MEM_new(), BUF_MEM_free() and BUF_MEM_grow() are
       available in all versions of SSLeay and OpenSSL.
       BUF_strdup() was added in SSLeay 0.8.



0.9.7c                     2000-09-20                 buffer(3)
