/***************************************************************************
* Function : MakeBitFile
* Description: This function naively wraps a standard file in a
* bit_file_t structure. ANSI-C doesn't support file status
* functions commonly found in other C variants, so the
* caller must be passed as a parameter.
* Parameters : stream - pointer to the standard file being wrapped.
* mode - The mode of the file being wrapped.
* Effects : A bit_file_t structure will be created for the stream
* passed as a parameter.
* Returned : Pointer to the bit_file_t structure for the bit file
* or NULL on failure. errno will be set for all failure
* cases.
***************************************************************************/
bit_file_t *MakeBitFile(FILE *stream, const BF_MODES mode)
{
bit_file_t *bf;
if (stream == NULL)
{
/* can't wrapper empty steam */
errno = EBADF;
bf = NULL;
}
else
{
bf = (bit_file_t *)malloc(sizeof(bit_file_t));
if (bf == NULL)
{
/* malloc failed */
errno = ENOMEM;
}
else
{
/* set structure data */
bf->fp = stream;
bf->bitBuffer = 0;
bf->bitCount = 0;
bf->mode = mode;
bf->endian = DetermineEndianess();
}
}
return (bf);
}
bit_file_t *BitFileOpen(const char *fileName, const BF_MODES mode)
{
char modes[3][3] = {"rb", "wb", "ab"}; /* binary modes for fopen */
bit_file_t *bf;
bf = (bit_file_t *)malloc(sizeof(bit_file_t));
if (bf == NULL)
{
/* malloc failed */
errno = ENOMEM;
}
else
{
bf->fp = fopen(fileName, modes[mode]);
if (bf->fp == NULL)
{
/* fopen failed */
free(bf);
bf = NULL;
}
else
{
/* fopen succeeded fill in remaining bf data */
bf->bitBuffer = 0;
bf->bitCount = 0;
bf->mode = mode;
bf->endian = DetermineEndianess();
}
}
return (bf);
}
/***************************************************************************
* Function : BitFileOpen
* Description: This function opens a bit file for reading, writing,
* or appending. If successful, a bit_file_t data
* structure will be allocated and a pointer to the
* structure will be returned.
* Parameters : fileName - NULL terminated string containing the name of
* the file to be opened.
* mode - The mode of the file to be opened
* Effects : The specified file will be opened and file structure will
* be allocated.
* Returned : Pointer to the bit_file_t structure for the bit file
* opened, or NULL on failure. errno will be set for all
* failure cases.
***************************************************************************/
bit_file_t *BitFileOpen(const char *fileName, const BF_MODES mode)
{
char modes[3][3] = {"rb", "wb", "ab"}; /* binary modes for fopen */
bit_file_t *bf;
bf = (bit_file_t *)malloc(sizeof(bit_file_t));
if (bf == NULL)
{
/* malloc failed */
errno = ENOMEM;
}
else
{
bf->fp = fopen(fileName, modes[mode]);
if (bf->fp == NULL)
{
/* fopen failed */
free(bf);
bf = NULL;
}
else
{
/* fopen succeeded fill in remaining bf data */
bf->bitBuffer = 0;
bf->bitCount = 0;
bf->mode = mode;
bf->endian = DetermineEndianess();
/***************************************************************
* TO DO: Consider using the last byte in a file to indicate
* the number of bits in the previous byte that actually have
* data. If I do that, I'll need special handling of files
* opened with a mode of BF_APPEND.
***************************************************************/
}
}
return (bf);
}
