EXPR(1) User Commands EXPR(1)
expr - evaluate expressions
--help display this help and exit
output version information and exit
Print the value of EXPRESSION to standard output. A blank line below
separates increasing precedence groups. EXPRESSION may be:
ARG1 | ARG2
ARG1 if it is neither null nor 0, otherwise ARG2
ARG1 & ARG2
ARG1 if neither argument is null or 0, otherwise 0
ARG1 < ARG2
ARG1 is less than ARG2
ARG1 <= ARG2
ARG1 is less than or equal to ARG2
ARG1 = ARG2
ARG1 is equal to ARG2
ARG1 != ARG2
ARG1 is unequal to ARG2
ARG1 >= ARG2
ARG1 is greater than or equal to ARG2
ARG1 > ARG2
ARG1 is greater than ARG2
ARG1 + ARG2
arithmetic sum of ARG1 and ARG2
ARG1 - ARG2
arithmetic difference of ARG1 and ARG2
ARG1 * ARG2
arithmetic product of ARG1 and ARG2
ARG1 / ARG2
arithmetic quotient of ARG1 divided by ARG2
ARG1 % ARG2
arithmetic remainder of ARG1 divided by ARG2
STRING : REGEXP
anchored pattern match of REGEXP in STRING
match STRING REGEXP
same as STRING : REGEXP
substr STRING POS LENGTH
substring of STRING, POS counted from 1
index STRING CHARS
index in STRING where any CHARS is found, or 0
length of STRING
interpret TOKEN as a string, even if it is a
keyword like 'match' or an operator like '/'
( EXPRESSION )
value of EXPRESSION
Beware that many operators need to be escaped or quoted for shells.
Comparisons are arithmetic if both ARGs are numbers, else lexicographi-
cal. Pattern matches return the string matched between \( and \) or
null; if \( and \) are not used, they return the number of characters
matched or 0.
Exit status is 0 if EXPRESSION is neither null nor 0, 1 if EXPRESSION
is null or 0, 2 if EXPRESSION is syntactically invalid, and 3 if an
Written by Mike Parker, James Youngman, and Paul Eggert.
GNU coreutils online help: <https://www.gnu.org/software/coreutils/>
Report expr translation bugs to <https://translationproject.org/team/>
Copyright (C) 2018 Free Software Foundation, Inc. License GPLv3+: GNU
GPL version 3 or later <https://gnu.org/licenses/gpl.html>.
This is free software: you are free to change and redistribute it.
There is NO WARRANTY, to the extent permitted by law.
Full documentation at: <https://www.gnu.org/software/coreutils/expr>
or available locally via: info '(coreutils) expr invocation'
GNU coreutils 8.30 August 2018 EXPR(1)