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.  Com‐
       parisons  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
       Written by Mike Parker, James Youngman, and Paul Eggert.

REPORTING BUGS
       Report expr bugs to bug-coreutils@gnu.org
       GNU coreutils home page: <http://www.gnu.org/software/coreutils/>
       General help using GNU software: <http://www.gnu.org/gethelp/>
       Report expr translation bugs to <http://translationproject.org/team/>

COPYRIGHT
       Copyright © 2011 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
       The full documentation for expr is maintained as a  Texinfo  manual.   If
       the  info and expr programs are properly installed at your site, the com‐
       mand

              info coreutils 'expr invocation'

       should give you access to the complete manual.



GNU coreutils 8.12.197-032bb     September 2011                          EXPR(1)