NAME | SYNOPSIS | DESCRIPTION | AUTHOR | REPORTING BUGS | COPYRIGHT | SEE ALSO | COLOPHON

EXPR(1)                         User Commands                        EXPR(1)

NAME         top

       expr - evaluate expressions

SYNOPSIS         top

       expr EXPRESSION
       expr OPTION

DESCRIPTION         top

       --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 EXPRESSION
       is null or 0, 2 if EXPRESSION is syntactically invalid, and 3 if an
       error occurred.

AUTHOR         top

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

REPORTING BUGS         top

       GNU coreutils online help: <http://www.gnu.org/software/coreutils/>
       Report expr translation bugs to <http://translationproject.org/team/>

COPYRIGHT         top

       Copyright © 2016 Free Software Foundation, Inc.  License GPLv3+: GNU
       GPL version 3 or later <http://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         top

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

COLOPHON         top

       This page is part of the coreutils (basic file, shell and text
       manipulation utilities) project.  Information about the project can
       be found at ⟨http://www.gnu.org/software/coreutils/⟩.  If you have a
       bug report for this manual page, see 
       ⟨http://www.gnu.org/software/coreutils/⟩.  This page was obtained from
       the tarball coreutils-8.25.tar.xz fetched from 
       ⟨http://www.gnutls.org/download.html⟩ on 2016-09-01.  If you discover
       any rendering problems in this HTML version of the page, or you
       believe there is a better or more up-to-date source for the page, or
       you have corrections or improvements to the information in this
       COLOPHON (which is not part of the original manual page), send a mail
       to man-pages@man7.org

GNU coreutils 8.25              January 2016                         EXPR(1)