From f19e3c1c6c96e3c709ac732ff70c586521f792d3 Mon Sep 17 00:00:00 2001 From: Denys Vlasenko Date: Sun, 28 Jan 2018 20:13:33 +0100 Subject: shell: handle $((NUM++...) like bash does. Closes 10706 function old new delta evaluate_string 680 729 +49 Signed-off-by: Denys Vlasenko --- shell/math.c | 19 +++++++++++++++++-- 1 file changed, 17 insertions(+), 2 deletions(-) (limited to 'shell/math.c') diff --git a/shell/math.c b/shell/math.c index f01f24362..611b3beab 100644 --- a/shell/math.c +++ b/shell/math.c @@ -598,10 +598,24 @@ 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: + * "a+++v" is a++ + v. + * "7+++v" is 7 + ++v, not 7++ + v. + */ + if (lasttok == TOK_NUM && !numstackptr[-1].var /* number literal */ + && (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; + } + p = op_tokens; while (1) { -// TODO: bash allows 7+++v, treats it as 7 + ++v -// we treat it as 7++ + v and reject /* Compare expr to current op_tokens[] element */ const char *e = expr; while (1) { @@ -627,6 +641,7 @@ evaluate_string(arith_state_t *math_state, const char *expr) } tok_found: op = p[1]; /* fetch TOK_foo value */ + tok_found1: /* NB: expr now points past the operator */ /* post grammar: a++ reduce to num */ -- cgit v1.2.3