22 starts writing at the first NUL byte.  If <[buf]> is NULL, then
23 <[size]> bytes are automatically provided as if by <<malloc>>, with
30 than <[size]>.  If <[mode]> starts with <<r>>, the position starts at
31 <<0>>, and file size starts at <[size]> if <[buf]> was provided.  If
33 and if <[buf]> was provided, the first byte is set to NUL.  If
35 location of the first NUL byte, or else <[size]> if <[buf]> was
44 if there is still room; if the stream is not also open for reading, a
54 <<NULL>> is returned, and <<errno>> will be set to EINVAL if <[size]>
55 is zero or <[mode]> is invalid, ENOMEM if <[buf]> was NULL and memory
56 could not be allocated, or EMFILE if too many streams are already
79   char append; /* nonzero if appending */
80   char writeonly; /* 1 if write-only */
94   if (c->pos > c->eof)  in fmemreader()
96   if (n >= c->eof - c->pos)  in fmemreader()
112   int adjust = 0; /* true if at EOF, but still need to write NUL.  */  in fmemwriter()
114   /* Append always seeks to eof; otherwise, if we have previously done  in fmemwriter()
116   if (c->append)  in fmemwriter()
118   else if (c->pos > c->eof)  in fmemwriter()
121   if (c->pos + n > c->max - c->writeonly)  in fmemwriter()
126   /* Now n is the number of bytes being modified, and adjust is 1 if  in fmemwriter()
127      the last byte is NUL instead of from buf.  Write a NUL if  in fmemwriter()
128      write-only; or if read-write, eof changed, and there is still  in fmemwriter()
130      overwrite so we can restore it if we seek elsewhere later.  */  in fmemwriter()
131   if (c->pos + n > c->eof)  in fmemwriter()
134       if (c->eof - adjust < c->max)  in fmemwriter()
137   else if (c->writeonly)  in fmemwriter()
139       if (n)  in fmemwriter()
148   if (n - adjust)  in fmemwriter()
173   if (whence == SEEK_CUR)  in fmemseeker()
175   else if (whence == SEEK_END)  in fmemseeker()
177   if (offset < 0)  in fmemseeker()
182   else if (offset > (off_t) c->max)  in fmemseeker()
188   else if ((_fpos_t) offset != offset)  in fmemseeker()
196       if (c->writeonly && c->pos < c->eof)  in fmemseeker()
202       if (c->writeonly && c->pos < c->eof)  in fmemseeker()
222   if (whence == SEEK_CUR)  in fmemseeker64()
224   else if (whence == SEEK_END)  in fmemseeker64()
226   if (offset < 0)  in fmemseeker64()
231   else if (offset > (_off64_t) c->max)  in fmemseeker64()
238       if (c->writeonly && c->pos < c->eof)  in fmemseeker64()
244       if (c->writeonly && c->pos < c->eof)  in fmemseeker64()
277   if ((flags = __sflags (mode, &dummy)) == 0)  in fmemopen()
279   if (!size || !(buf || flags & __SRW))  in fmemopen()
284   if ((fp = __sfp ()) == NULL)  in fmemopen()
286   if ((c = (fmemcookie *) malloc (sizeof *c + (buf ? 0 : size)))  in fmemopen()
304   if (!buf)  in fmemopen()
321 	  if (!buf && c->writeonly)  in fmemopen()
322 	    /* a: guarantee a NUL within size even if no writes.  */  in fmemopen()