buffer(3)

     buffer(3)              0.9.6h (2000-09-19)              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 "miscellaneous"
          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 contains
          sensitive data.

          BUF_MEM_grow() changes the size of an already existing
          buffer to len. Any data already in the buffer is preserved
          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

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     buffer(3)              0.9.6h (2000-09-19)              buffer(3)

          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.

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