Date: Mon, 27 Jan 1997 04:32:32 +1100 From: Bruce Evans <bde@zeta.org.au> To: current@freebsd.org Cc: steve@freebsd.org Subject: sh expression printing bug Message-ID: <199701261732.EAA03702@godzilla.zeta.org.au>
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/bin/sh prints the wrong value for `echo $((1 << 30))'. This is
because expari() only provides a 10-character buffer for printing the
result of an integer expression. 12 characters are required even
on 32-bit machines (10 digits, one sign and one nul). The length
it checked, so there is no buffer overflow bug - the output is
just truncated. I made the following quick fix for the 32-bit case.
I don't know exactly why the CHECKSTRSPACE() arg is 2 less than the
size required.
Bruce
diff -c2 expand.c~ expand.c
*** expand.c~ Tue Jan 14 22:19:21 1997
--- expand.c Sun Jan 26 03:36:20 1997
***************
*** 336,340 ****
* characters have to be processed left to right.
*/
! CHECKSTRSPACE(8, expdest);
USTPUTC('\0', expdest);
start = stackblock();
--- 336,343 ----
* characters have to be processed left to right.
*/
! #if INT_MAX / 1000000000 >= 10 || INT_MIN / 1000000000 <= -10
! #error "integers with more than 10 digits are not supported"
! #endif
! CHECKSTRSPACE(12 - 2, expdest);
USTPUTC('\0', expdest);
start = stackblock();
***************
*** 351,355 ****
rmescapes(p+1);
result = arith(p+1);
! fmtstr(p, 10, "%d", result);
while (*p++)
;
--- 354,358 ----
rmescapes(p+1);
result = arith(p+1);
! fmtstr(p, 12, "%d", result);
while (*p++)
;
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