EXPR(1) EXPR(1) expr -- expr expr --help --version . , . : 1 | 2 1, 0, 2 1 & 2 1, 0, 0 1 < 2 1 2 1 <= 2 1 2 1 = 2 1 2 1 != 2 1 2 1 >= 2 1 2 1 > 2 1 2 1 + 2 1 2 1 - 2 1 2 1 * 2 1 2 1 / 2 1 2 1 % 2 1 2 : _ _ match _ , : _ substr , 1 index , , 0 length + interpret TOKEN as a string, even if it is a keyword like 'match' or an operator like '/' ( ) , . , , . , \( \), ; \( \) , 0. 0, 0; 1, 0; 2, ; 3, . (Mike Parker), (James Youngman) (Paul Eggert). - GNU coreutils: Copyright (C) 2025 Free Software Foundation, Inc. GPLv3+: GNU GPL 3 . : . , . , info '(coreutils) expr invocation' () Kirill Rekhov ; GNU (GNU General Public License - GPL, 3 ) , - . - , , () () () <>. GNU coreutils 9.7 2025 . EXPR(1)