ungetc will put characters back into an _IOSTRG input stream
Michael "Ford" Ditto
ditto at cbmvax.UUCP
Tue Feb 14 12:43:58 AEST 1989
In article <20282 at lll-winken.LLNL.GOV> casey at lll-crg.llnl.gov (Casey Leedom) writes:
> ! if (iop->_flag & _IOSTRG)
> ! --iop->_ptr;
> ! else
> ! *--iop->_ptr = c;
As an alternative to the above four lines, why not:
if (*--iop->_ptr != (char)c)
*iop->ptr = c;
This will give anyone ungetc'ing something weird into a readonly string
the segmentation fault they deserve, and still allow ungetc'ing into
a writable string (even though nobody should be doing that).
--
-=] Ford [=-
"The number of Unix installations (In Real Life: Mike Ditto)
has grown to 10, with more expected." ford at kenobi.cts.com
- The Unix Programmer's Manual, ...!sdcsvax!crash!elgar!ford
2nd Edition, June, 1972. ditto at cbmvax.commodore.com
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