expr(1) — Linux manual page


EXPR(1)                       User Commands                      EXPR(1)

NAME         top

       expr - evaluate expressions

SYNOPSIS         top

       expr EXPRESSION
       expr OPTION

DESCRIPTION         top

       --help display this help and exit

              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

              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 syntactically
       invalid, and 3 if an error occurred.

AUTHOR         top

       Written by Mike Parker, James Youngman, and Paul Eggert.

REPORTING BUGS         top

       GNU coreutils online help:
       Report any translation bugs to

COPYRIGHT         top

       Copyright © 2024 Free Software Foundation, Inc.  License GPLv3+:
       GNU GPL version 3 or later <https://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         top

       Full documentation <https://www.gnu.org/software/coreutils/expr>
       or available locally via: info '(coreutils) expr invocation'

COLOPHON         top

       This page is part of the coreutils (basic file, shell and text
       manipulation utilities) project.  Information about the project
       can be found at ⟨http://www.gnu.org/software/coreutils/⟩.  If you
       have a bug report for this manual page, see
       ⟨http://www.gnu.org/software/coreutils/⟩.  This page was obtained
       from the tarball coreutils-9.5.tar.xz fetched from
       ⟨http://ftp.gnu.org/gnu/coreutils/⟩ on 2024-06-14.  If you
       discover any rendering problems in this HTML version of the page,
       or you believe there is a better or more up-to-date source for
       the page, or you have corrections or improvements to the
       information in this COLOPHON (which is not part of the original
       manual page), send a mail to man-pages@man7.org

GNU coreutils 9.5              March 2024                        EXPR(1)

Pages that refer to this page: sysconf(3)