EXPR

EXPR

NAME SYNOPSIS DESCRIPTION AUTHOR REPORTING BUGS COPYRIGHT SEE ALSO

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

ARG1 if neither argument is null or 0, otherwise 0

ARG1

ARG1 is less than ARG2

ARG1

ARG1 is less than or equal to ARG2

ARG1 = ARG2

ARG1 is equal to ARG2

ARG1 != ARG2

ARG1 is unequal to ARG2

ARG1

ARG1 is greater than or equal to ARG2

ARG1

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

quote 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.

expr exits with:

0 if the expression is neither null nor 0; 1 if the expression is null or 0; or 2 for invalid expressions.

AUTHOR

Written by Mike Parker.

REPORTING BUGS

Report bugs to

COPYRIGHT

Copyright 2000 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.