amos@instable.UUCP (02/24/87)
Index: <source directory>/<source file> 4.2BSD
Description:
Expr doesn't recognize negative numbers as numeric arguments,
except as the 1st argument to a relational operation (this is
even more bogous, since non-numeric arguments are compared
lexically, without warning).
Repeat-By:
Try: expr -1 + 2; or expr -1 \> -01
This is most annoying when expr-ing the output of another expr.
Fix:
Apply the following patch. (This is from the vanilla 4.3 sources,
but other versions - maybe even sysV? - are similar).
*** /usr/src/bin/expr.y Mon Mar 3 16:42:15 1986
--- /tmp/expr.y Tue Feb 24 16:30:24 1987
***************
*** 94,100
char *rel(op, r1, r2) register char *r1, *r2; {
register long i;
! if(ematch(r1, "-*[0-9]*$") && ematch(r2, "-*[0-9]*$"))
i = atol(r1) - atol(r2);
else
i = strcmp(r1, r2);
--- 94,100 -----
char *rel(op, r1, r2) register char *r1, *r2; {
register long i;
! if(ematch(r1, "-*[0-9]*$") && ematch(r2, "[0-9]*$"))
i = atol(r1) - atol(r2);
else
i = strcmp(r1, r2);
***************
*** 113,119
long i1, i2;
register char *rv;
! if(!(ematch(r1, "-*[0-9]*$") && ematch(r2, "-*[0-9]*$")))
yyerror("non-numeric argument");
i1 = atol(r1);
i2 = atol(r2);
--- 113,119 -----
long i1, i2;
register char *rv;
! if(!(ematch(r1, "[0-9]*$") && ematch(r2, "[0-9]*$")))
yyerror("non-numeric argument");
i1 = atol(r1);
i2 = atol(r2);
--
Amos Shapir
National Semiconductor (Israel)
6 Maskit st. P.O.B. 3007, Herzlia 46104, Israel
(011-972) 52-522261 amos%nsta@nsc.com 34.48'E 32.10'Namos@instable.UUCP (02/25/87)
Sorry, the Index line slipped by me in my previous posting. It is, of course: Index: /usr/src/bin/expr.y -- Amos Shapir National Semiconductor (Israel) 6 Maskit st. P.O.B. 3007, Herzlia 46104, Israel (011-972) 52-522261 amos%nsta@nsc.com 34.48'E 32.10'N