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 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 <bug-coreutils@gnu.org>.

COPYRIGHT
    Copyright (C) 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.