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Full Discussion: Why is ./ sometimes needed?
Top Forums Shell Programming and Scripting Why is ./ sometimes needed? Post 303029723 by wisecracker on Thursday 31st of January 2019 07:21:32 AM
Old 01-31-2019
Thanks Don...

There is this however, reference to OSX 10.14.1, default bash terminal:
Code:
Last login: Thu Jan 31 12:05:01 on ttys000
AMIGA:amiga~> man true
AMIGA:amiga~> help true
true: true
    Return a successful result.
AMIGA:amiga~> man false
AMIGA:amiga~> help false
false: false
    Return an unsuccessful result.
AMIGA:amiga~> man :
No manual entry for :
AMIGA:amiga~> help :
:: :
    No effect; the command does nothing.  A zero exit code is returned.
AMIGA:amiga~> 
AMIGA:amiga~> which true
/usr/bin/true
AMIGA:amiga~> which false
/usr/bin/false
AMIGA:amiga~> which :
AMIGA:amiga~> _

Both XUbuntu56 and I can learn from your expertise on this.
I have not copied and pasted the man pages but they do exist.

As you can see there is a manual AND a help entry for "true" and "false", do I take it the some shells, perhaps dash or ash, do not have these as builtins as it looks like I have both builtin and transient versions.
":" is builtin only so I assume that in POSIX this IS a requirement but the others are optional?

TIA.

Bazza...
 

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IS_STRING(3)								 1							      IS_STRING(3)

is_string - Find whether the type of a variable is string

SYNOPSIS
bool is_string (mixed $var) DESCRIPTION
Finds whether the type given variable is string. PARAMETERS
o $var - The variable being evaluated. RETURN VALUES
Returns TRUE if $var is of type string, FALSE otherwise. EXAMPLES
Example #1 is_string(3) example <?php $values = array(false, true, null, 'abc', '23', 23, '23.5', 23.5, '', ' ', '0', 0); foreach ($values as $value) { echo "is_string("; var_export($value); echo ") = "; echo var_dump(is_string($value)); } ?> The above example will output: is_string(false) = bool(false) is_string(true) = bool(false) is_string(NULL) = bool(false) is_string('abc') = bool(true) is_string('23') = bool(true) is_string(23) = bool(false) is_string('23.5') = bool(true) is_string(23.5) = bool(false) is_string('') = bool(true) is_string(' ') = bool(true) is_string('0') = bool(true) is_string(0) = bool(false) SEE ALSO
is_float(3), is_int(3), is_bool(3), is_object(3), is_array(3). PHP Documentation Group IS_STRING(3)
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