expr – evaluate expressions

USAGE
       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 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.

AUTHOR
       Written by Mike Parker.

REPORTING BUGS
       Report bugs to .

COPYRIGHT
       Copyright © 2002 Free Software Foundation, Inc.
       This is free software; see the source for copying conditions.  There is
       NO  warranty;  not even for MERCHANTABILITY or FITNESS FOR A PARTICULAR
       PURPOSE.

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
       command

              info expr

       should give you access to the complete manual.