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

AUTHOR
       Written by Mike Parker.

REPORTING BUGS
       Report bugs to <bug-coreutils@gnu.org>.

COPYRIGHT
       Copyright (C) 2004 Free Software Foundation, Inc.
       This is free software; see the source for copying condi-
       tions.  There is NO warranty; not even for MERCHANTABIL-
       ITY or FITNESS FOR A PARTICULAR PURPOSE.

SEE ALSO
       The  full documentation for expr is maintained as a Tex-
       info manual.  If the info and expr programs are properly
       installed at your site, the command

              info expr

       should give you access to the complete manual.



expr 5.3.0               November 2004                  EXPR(1)
