brachman@ubc-cs.UUCP (04/10/87)
Index: /usr/src/bin/expr.y 4.3BSD
Description:
Expr gags on negative numbers as numeric arguments or when an
intermediate result is negative.
This bug was reported earlier by Amos Shapir <amos@instable.uucp>
but his fix was not quite correct.
By the way, expr accepts both '=' and '==' as equality
operators. This is not documented in the man page.
Repeat-By:
Try:
expr -1 + 2
or:
expr 5 - 6 + 3
If you've applied Amos Shapir's "fix" try:
-4 + --6
Fix:
Two sets of context diffs follow. The first (diffs1) simply corrects
the bug. The second (diffs2) corrects the bug and also cleans up the
code so that cc and lint are happier. Both fixes assume the original
source code.
-----
Barry Brachman | {ihnp4!alberta,uw-beaver,seismo}!
Dept. of Computer Science| ubc-vision!ubc-cs!brachman
Univ. of British Columbia| brachman@cs.ubc.cdn
Vancouver, B.C. V6T 1W5 | brachman%ubc.csnet@csnet-relay.arpa
(604) 228-4327 | brachman@ubc.csnet
----- CUT HERE ----- CUT HERE ----- CUT HERE ----- CUT HERE ----- CUT HERE
: This is a shar archive. Extract with sh, not csh.
: This archive ends with exit, so do not worry about trailing junk.
: Created by brachman@ubc-csgrads on Thu Apr 9 16:21:49 PDT 1987
echo 'Extracting diffs1'
sed 's/^X//' > diffs1 << '+ END-OF-FILE diffs1'
X*** expr.y Thu Apr 9 13:02:51 1987
X--- expr.new.y Thu Apr 9 14:06:24 1987
X***************
X*** 113,119 ****
X long i1, i2;
X register char *rv;
X
X! if(!(ematch(r1, "[0-9]*$") && ematch(r2, "[0-9]*$")))
X yyerror("non-numeric argument");
X i1 = atol(r1);
X i2 = atol(r2);
X--- 114,121 ----
X long i1, i2;
X register char *rv;
X
X! if(!((ematch(r1, "[0-9]*$") || ematch(r1, "-[0-9]*$")) &&
X! (ematch(r2, "[0-9]*$") || ematch(r2, "-[0-9]*$"))))
X yyerror("non-numeric argument");
X i1 = atol(r1);
X i2 = atol(r2);
X
+ END-OF-FILE diffs1
chmod 'u=rw,g=r,o=r' 'diffs1'
echo ' -rw-r--r-- 1 brachman 533 Apr 9 16:19 diffs1 (as sent)'
echo -n ' '
/bin/ls -l diffs1
echo 'Extracting diffs2'
sed 's/^X//' > diffs2 << '+ END-OF-FILE diffs2'
X*** expr.y Thu Apr 9 13:02:51 1987
X--- expr.new.y Thu Apr 9 14:06:24 1987
X***************
X*** 18,48 ****
X /* a single `expression' is evaluated and printed: */
X
X expression: expr NOARG = {
X! printf("%s\n", $1);
X! exit((!strcmp($1,"0")||!strcmp($1,"\0"))? 1: 0);
X }
X ;
X
X
X expr: '(' expr ')' = { $$ = $2; }
X! | expr OR expr = { $$ = conj(OR, $1, $3); }
X! | expr AND expr = { $$ = conj(AND, $1, $3); }
X! | expr EQ expr = { $$ = rel(EQ, $1, $3); }
X! | expr GT expr = { $$ = rel(GT, $1, $3); }
X! | expr GEQ expr = { $$ = rel(GEQ, $1, $3); }
X! | expr LT expr = { $$ = rel(LT, $1, $3); }
X! | expr LEQ expr = { $$ = rel(LEQ, $1, $3); }
X! | expr NEQ expr = { $$ = rel(NEQ, $1, $3); }
X! | expr ADD expr = { $$ = arith(ADD, $1, $3); }
X! | expr SUBT expr = { $$ = arith(SUBT, $1, $3); }
X! | expr MULT expr = { $$ = arith(MULT, $1, $3); }
X! | expr DIV expr = { $$ = arith(DIV, $1, $3); }
X! | expr REM expr = { $$ = arith(REM, $1, $3); }
X! | expr MCH expr = { $$ = match($1, $3); }
X! | MATCH expr expr = { $$ = match($2, $3); }
X! | SUBSTR expr expr expr = { $$ = substr($2, $3, $4); }
X! | LENGTH expr = { $$ = length($2); }
X! | INDEX expr expr = { $$ = index($2, $3); }
X | A_STRING
X ;
X %%
X--- 18,48 ----
X /* a single `expression' is evaluated and printed: */
X
X expression: expr NOARG = {
X! (void) printf("%s\n", $1);
X! exit((!strcmp((char *) $1,"0")||!strcmp((char *) $1,"\0"))? 1: 0);
X }
X ;
X
X
X expr: '(' expr ')' = { $$ = $2; }
X! | expr OR expr = { $$ = (YYSTYPE) conj(OR, (char *) $1, (char *) $3); }
X! | expr AND expr = { $$ = (YYSTYPE) conj(AND, (char *) $1, (char *) $3); }
X! | expr EQ expr = { $$ = (YYSTYPE) rel(EQ, (char *) $1, (char *) $3); }
X! | expr GT expr = { $$ = (YYSTYPE) rel(GT, (char *) $1, (char *) $3); }
X! | expr GEQ expr = { $$ = (YYSTYPE) rel(GEQ, (char *) $1, (char *) $3); }
X! | expr LT expr = { $$ = (YYSTYPE) rel(LT, (char *) $1, (char *) $3); }
X! | expr LEQ expr = { $$ = (YYSTYPE) rel(LEQ, (char *) $1, (char *) $3); }
X! | expr NEQ expr = { $$ = (YYSTYPE) rel(NEQ, (char *) $1, (char *) $3); }
X! | expr ADD expr = { $$ = (YYSTYPE) arith(ADD, (char *) $1, (char *) $3); }
X! | expr SUBT expr = { $$ = (YYSTYPE)arith(SUBT, (char *) $1, (char *) $3); }
X! | expr MULT expr = { $$ = (YYSTYPE)arith(MULT, (char *) $1, (char *) $3); }
X! | expr DIV expr = { $$ = (YYSTYPE) arith(DIV, (char *) $1, (char *) $3); }
X! | expr REM expr = { $$ = (YYSTYPE) arith(REM, (char *) $1, (char *) $3); }
X! | expr MCH expr = { $$ = (YYSTYPE) match((char *) $1, (char *) $3); }
X! | MATCH expr expr = { $$ = (YYSTYPE) match((char *) $2, (char *) $3); }
X! | SUBSTR expr expr expr = { $$ = (YYSTYPE) substr((char *) $2, (char *) $3, (char *) $4); }
X! | LENGTH expr = { $$ = (YYSTYPE) length((char *) $2); }
X! | INDEX expr expr = { $$ = (YYSTYPE) index((char *) $2, (char *) $3); }
X | A_STRING
X ;
X %%
X***************
X*** 60,70 ****
X char *malloc();
X extern int nbra;
X
X main(argc, argv) char **argv; {
X Ac = argc;
X Argi = 1;
X Av = argv;
X! yyparse();
X }
X
X char *operators[] = { "|", "&", "+", "-", "*", "/", "%", ":",
X--- 60,71 ----
X char *malloc();
X extern int nbra;
X
X+ char *sprintf(), *strcpy(), *strncpy();
X main(argc, argv) char **argv; {
X Ac = argc;
X Argi = 1;
X Av = argv;
X! (void) yyparse();
X }
X
X char *operators[] = { "|", "&", "+", "-", "*", "/", "%", ":",
X***************
X*** 87,93 ****
X if(EQL(operators[i], p))
X return op[i];
X
X! yylval = p;
X return A_STRING;
X }
X
X--- 88,94 ----
X if(EQL(operators[i], p))
X return op[i];
X
X! yylval = (YYSTYPE) p;
X return A_STRING;
X }
X
X***************
X*** 113,119 ****
X long i1, i2;
X register char *rv;
X
X! if(!(ematch(r1, "[0-9]*$") && ematch(r2, "[0-9]*$")))
X yyerror("non-numeric argument");
X i1 = atol(r1);
X i2 = atol(r2);
X--- 114,121 ----
X long i1, i2;
X register char *rv;
X
X! if(!((ematch(r1, "[0-9]*$") || ematch(r1, "-[0-9]*$")) &&
X! (ematch(r2, "[0-9]*$") || ematch(r2, "-[0-9]*$"))))
X yyerror("non-numeric argument");
X i1 = atol(r1);
X i2 = atol(r2);
X***************
X*** 126,132 ****
X case REM: i1 = i1 % i2; break;
X }
X rv = malloc(16);
X! sprintf(rv, "%D", i1);
X return rv;
X }
X char *conj(op, r1, r2) char *r1, *r2; {
X--- 128,134 ----
X case REM: i1 = i1 % i2; break;
X }
X rv = malloc(16);
X! (void) sprintf(rv, "%D", i1);
X return rv;
X }
X char *conj(op, r1, r2) char *r1, *r2; {
X***************
X*** 182,188 ****
X while(*s++) ++i;
X
X rv = malloc(8);
X! sprintf(rv, "%d", i);
X return rv;
X }
X
X--- 184,190 ----
X while(*s++) ++i;
X
X rv = malloc(8);
X! (void) sprintf(rv, "%d", i);
X return rv;
X }
X
X***************
X*** 193,199 ****
X for(i = 0; s[i] ; ++i)
X for(j = 0; t[j] ; ++j)
X if(s[i]==t[j]) {
X! sprintf(rv = malloc(8), "%d", ++i);
X return rv;
X }
X return "0";
X--- 195,201 ----
X for(i = 0; s[i] ; ++i)
X for(j = 0; t[j] ; ++j)
X if(s[i]==t[j]) {
X! (void) sprintf(rv = malloc(8), "%d", ++i);
X return rv;
X }
X return "0";
X***************
X*** 200,212 ****
X }
X
X char *match(s, p)
X {
X register char *rv;
X
X! sprintf(rv = malloc(8), "%d", ematch(s, p));
X if(nbra) {
X! rv = malloc(strlen(Mstring[0])+1);
X! strcpy(rv, Mstring[0]);
X }
X return rv;
X }
X--- 202,215 ----
X }
X
X char *match(s, p)
X+ char *s, *p;
X {
X register char *rv;
X
X! (void) sprintf(rv = malloc(8), "%d", ematch(s, p));
X if(nbra) {
X! rv = malloc((unsigned int) (strlen(Mstring[0])+1));
X! (void) strcpy(rv, Mstring[0]);
X }
X return rv;
X }
X***************
X*** 235,241 ****
X if(nbra == 1) {
X p = braslist[0];
X num = braelist[0] - p;
X! strncpy(Mstring[0], p, num);
X Mstring[0][num] = '\0';
X }
X return(loc2-s);
X--- 238,244 ----
X if(nbra == 1) {
X p = braslist[0];
X num = braelist[0] - p;
X! (void) strncpy(Mstring[0], p, num);
X Mstring[0][num] = '\0';
X }
X return(loc2-s);
X***************
X*** 243,249 ****
X--- 246,254 ----
X return(0);
X }
X
X+ /*ARGSUSED*/
X errxx(c)
X+ int c;
X {
X yyerror("RE error");
X }
X***************
X*** 647,653 ****
X register char *str;
X {
X low = *str++ & 0377;
X! size = *str == 255 ? 20000 : (*str &0377) - low;
X }
X
X ecmp(a, b, count)
X--- 652,658 ----
X register char *str;
X {
X low = *str++ & 0377;
X! size = (int) (*str & 0377) == 255 ? 20000 : (int) (*str &0377) - low;
X }
X
X ecmp(a, b, count)
X***************
X*** 663,670 ****
X
X static char *sccsid = "@(#)expr.y 4.4 (Berkeley) 5/21/84";
X yyerror(s)
X!
X {
X! fprintf(stderr, "%s\n", s);
X exit(2);
X }
X--- 668,675 ----
X
X static char *sccsid = "@(#)expr.y 4.4 (Berkeley) 5/21/84";
X yyerror(s)
X! char *s;
X {
X! (void) fprintf(stderr, "%s\n", s);
X exit(2);
X }
+ END-OF-FILE diffs2
chmod 'u=rw,g=r,o=r' 'diffs2'
echo ' -rw-r--r-- 1 brachman 6755 Apr 9 14:12 diffs2 (as sent)'
echo -n ' '
/bin/ls -l diffs2
exit 0