EXPR(1)                       User Commands                       EXPR(1)

NAME
       expr - evaluate expressions

SYNOPSIS
       expr EXPRESSION
       expr OPTION

DESCRIPTION
       --help display this help and exit

       --version
              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 STRING
              length of STRING

       + TOKEN
              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
       lexicographical.   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 EXPRES‐
       SION is null or 0, 2 if EXPRESSION is syntactically invalid, and 3
       if an error occurred.

AUTHOR
       Written by Mike Parker, James Youngman, and Paul Eggert.

REPORTING BUGS
       GNU  coreutils  online  help:  <https://www.gnu.org/software/core‐
       utils/>
       Report    any   translation   bugs   to   <https://translationpro‐
       ject.org/team/>

COPYRIGHT
       Copyright © 2020 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.

SEE ALSO
       Full documentation <https://www.gnu.org/software/coreutils/expr>
       or available locally via: info '(coreutils) expr invocation'

GNU coreutils 8.32              April 2020                        EXPR(1)