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Top Forums Shell Programming and Scripting nested logical expression in bash shell Post 302602622 by ysrini on Monday 27th of February 2012 11:37:48 PM
Old 02-28-2012
Using the recommended operators how can i write the following?
Code:
if NOT [ $var -eq 'a' || $var = 'b' || $var = 'c' ]
then
 ....
fi

I want to keep the '||' clause and do not want to translate into
Code:
if [ $var -ne 'a' && $var -ne 'b' && $var -ne 'c' ]

because using 'NOT' equivalent ahead upfront is much easier to understand the logic

I am using Korn shell

Thanks,
-srinivas y.

Last edited by ysrini; 02-28-2012 at 12:45 AM..
 

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IS_SCALAR(3)								 1							      IS_SCALAR(3)

is_scalar - Finds whether a variable is a scalar

SYNOPSIS
bool is_scalar (mixed $var) DESCRIPTION
Finds whether the given variable is a scalar. Scalar variables are those containing an integer, float, string or boolean. Types array, object and resource are not scalar. Note is_scalar(3) does not consider resource type values to be scalar as resources are abstract datatypes which are currently based on integers. This implementation detail should not be relied upon, as it may change. Note is_scalar(3) does not consider NULL to be scalar. PARAMETERS
o $var - The variable being evaluated. RETURN VALUES
Returns TRUE if $var is a scalar, FALSE otherwise. EXAMPLES
Example #1 is_scalar(3) example <?php function show_var($var) { if (is_scalar($var)) { echo $var; } else { var_dump($var); } } $pi = 3.1416; $proteins = array("hemoglobin", "cytochrome c oxidase", "ferredoxin"); show_var($pi); show_var($proteins) ?> The above example will output: 3.1416 array(3) { [0]=> string(10) "hemoglobin" [1]=> string(20) "cytochrome c oxidase" [2]=> string(10) "ferredoxin" } SEE ALSO
is_float(3), is_int(3), is_numeric(3), is_real(3), is_string(3), is_bool(3), is_object(3), is_array(3). PHP Documentation Group IS_SCALAR(3)
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