diff options
Diffstat (limited to 'shell/math.c')
| -rw-r--r-- | shell/math.c | 23 |
1 files changed, 15 insertions, 8 deletions
diff --git a/shell/math.c b/shell/math.c index 2942cdd26..049d5703b 100644 --- a/shell/math.c +++ b/shell/math.c @@ -668,19 +668,26 @@ evaluate_string(arith_state_t *math_state, const char *expr) /* Should be an operator */ - /* Special case: NUM-- and NUM++ are not recognized if NUM - * is a literal number, not a variable. IOW: + /* Special case: XYZ--, XYZ++, --XYZ, ++XYZ are recognized + * only if XYZ is a variable name, not a number or EXPR. IOW: * "a+++v" is a++ + v. * "7+++v" is 7 + ++v, not 7++ + v. + * "--7" is - - 7, not --7. + * "++++a" is + + ++a, not ++ ++ a. + * (we still mishandle "(a)+++7", should be treated as (a) + + + 7, but we do increment a) */ - if (lasttok == TOK_NUM && !numstackptr[-1].var /* number literal */ - && (expr[0] == '+' || expr[0] == '-') + if ((expr[0] == '+' || expr[0] == '-') && (expr[1] == expr[0]) ) { - //bb_error_msg("special %c%c", expr[0], expr[0]); - op = (expr[0] == '+' ? TOK_ADD : TOK_SUB); - expr += 1; - goto tok_found1; + if (numstackptr == numstack || !numstackptr[-1].var) { /* not a VAR++ */ + char next = skip_whitespace(expr + 2)[0]; + if (!(isalpha(next) || next == '_')) { /* not a ++VAR */ + //bb_error_msg("special %c%c", expr[0], expr[0]); + op = (expr[0] == '+' ? TOK_ADD : TOK_SUB); + expr++; + goto tok_found1; + } + } } p = op_tokens; |