in zlib/gzwrite.c [443:523]
int ZEXPORTVA gzprintf(gzFile file, const char *format, int a1, int a2, int a3,
int a4, int a5, int a6, int a7, int a8, int a9, int a10,
int a11, int a12, int a13, int a14, int a15, int a16,
int a17, int a18, int a19, int a20) {
unsigned len, left;
char *next;
gz_statep state;
z_streamp strm;
/* get internal structure */
if (file == NULL)
return Z_STREAM_ERROR;
state = (gz_statep)file;
strm = &(state->strm);
/* check that can really pass pointer in ints */
if (sizeof(int) != sizeof(void *))
return Z_STREAM_ERROR;
/* check that we're writing and that there's no error */
if (state->mode != GZ_WRITE || state->err != Z_OK)
return Z_STREAM_ERROR;
/* make sure we have some buffer space */
if (state->size == 0 && gz_init(state) == -1)
return state->error;
/* check for seek request */
if (state->seek) {
state->seek = 0;
if (gz_zero(state, state->skip) == -1)
return state->error;
}
/* do the printf() into the input buffer, put length in len -- the input
buffer is double-sized just for this function, so there is guaranteed to
be state->size bytes available after the current contents */
if (strm->avail_in == 0)
strm->next_in = state->in;
next = (char *)(strm->next_in + strm->avail_in);
next[state->size - 1] = 0;
#ifdef NO_snprintf
# ifdef HAS_sprintf_void
sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11, a12,
a13, a14, a15, a16, a17, a18, a19, a20);
for (len = 0; len < size; len++)
if (next[len] == 0)
break;
# else
len = sprintf(next, format, a1, a2, a3, a4, a5, a6, a7, a8, a9, a10, a11,
a12, a13, a14, a15, a16, a17, a18, a19, a20);
# endif
#else
# ifdef HAS_snprintf_void
snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8, a9,
a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
len = strlen(next);
# else
len = snprintf(next, state->size, format, a1, a2, a3, a4, a5, a6, a7, a8,
a9, a10, a11, a12, a13, a14, a15, a16, a17, a18, a19, a20);
# endif
#endif
/* check that printf() results fit in buffer */
if (len == 0 || len >= state->size || next[state->size - 1] != 0)
return 0;
/* update buffer and position, compress first half if past that */
strm->avail_in += len;
state->x.pos += len;
if (strm->avail_in >= state->size) {
left = strm->avail_in - state->size;
strm->avail_in = state->size;
if (gz_comp(state, Z_NO_FLUSH) == -1)
return state->err;
memmove(state->in, state->in + state->size, left);
strm->next_in = state->in;
strm->avail_in = left;
}
return (int)len;
}