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Full Discussion: A $(( expression )) bug?
Top Forums UNIX for Advanced & Expert Users A $(( expression )) bug? Post 302982344 by Don Cragun on Wednesday 28th of September 2016 08:05:38 AM
Old 09-28-2016
In an arithmetic evaluation, the value of a variable can be specified by expanding the variable (i.e. $var or ${var}) or by just giving the variable name (i.e. var). But the expression that is the numeric evaluation of the length of the string that is the value of a variable must use the expansion of the variable that produces that number (i.e. ${#var}); you cannot skip the ${ and } when you are using shell variable expansion operators like ${#var} or ${var%%pattern} or ${var:offset:length}.
 

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let(1)                                                             User Commands                                                            let(1)

NAME
let - shell built-in function to evaluate one or more arithmetic expressions SYNOPSIS
ksh let arg... DESCRIPTION
ksh Each arg is a separate "arithmetic expression" to be evaluated. EXIT STATUS
The following exit values are returned: 0 The value of the last expression is non-zero. 1 The value of the last expression is zero. ATTRIBUTES
See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcsu | +-----------------------------+-----------------------------+ SEE ALSO
ksh(1), set(1), typeset(1), attributes(5) SunOS 5.10 15 Apr 1994 let(1)
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