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 | |
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/>
COPYRIGHT
Copyright © 2009 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 command
info coreutils 'expr invocation' | |