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Full Discussion: what is that?
Top Forums UNIX for Advanced & Expert Users what is that? Post 30145 by Perderabo on Thursday 17th of October 2002 10:36:21 AM
Old 10-17-2002
Well semicolon lets you put two command on one line like this:
date ; uname -a

And $( ) sets x to the output of the command so x=`date` and x=$(date) do the same thing.

What the posted command is trying to do is to set x to the path of the get_tape routine. If get_tape does not exist in either place, x is null. If get_tape exists in exactly one of the places, x is that path.

But if get_tape exists in both places, x will be a two-line value with both paths in it. I wonder if the author of the code realizes that. Maybe that's what he wanted. Restricting the value of x to a single line would make this ugly construct even worse:
x=$([ -x /etc/get_tape ] && echo /etc/get_tape || { [ -x /abc/prog/bin/get_tape ] && echo /abc/prog/bin/get_tape; })

Personally, I think this really calls for explicit "if" statements. Then the code is much clearer, and much easier to maintain. But sometimes it is fun to crank out these opaque one-liners and I'm not really in a position to be casting too many stones here. Smilie
 
DATETIME.SETISODATE(3)							 1						    DATETIME.SETISODATE(3)

DateTime::setISODate - Sets the ISO date

       Object oriented style

SYNOPSIS
public DateTime DateTime::setISODate (int $year, int $week, [int $day = 1]) DESCRIPTION
Procedural style DateTime date_isodate_set (DateTime $object, int $year, int $week, [int $day = 1]) Set a date according to the ISO 8601 standard - using weeks and day offsets rather than specific dates. PARAMETERS
o $object -Procedural style only: A DateTime object returned by date_create(3). The function modifies this object. o $year - Year of the date. o $week - Week of the date. o $day - Offset from the first day of the week. RETURN VALUES
Returns the DateTime object for method chaining or FALSE on failure. CHANGELOG
+--------+---------------------------------------------------+ |Version | | | | | | | Description | | | | +--------+---------------------------------------------------+ | 5.3.0 | | | | | | | Changed the return value on success from NULL to | | | DateTime. | | | | +--------+---------------------------------------------------+ EXAMPLES
Example #1 DateTime.setISODate(3) example Object oriented style <?php $date = new DateTime(); $date->setISODate(2008, 2); echo $date->format('Y-m-d') . " "; $date->setISODate(2008, 2, 7); echo $date->format('Y-m-d') . " "; ?> Procedural style <?php $date = date_create(); date_isodate_set($date, 2008, 2); echo date_format($date, 'Y-m-d') . " "; date_isodate_set($date, 2008, 2, 7); echo date_format($date, 'Y-m-d') . " "; ?> The above examples will output: 2008-01-07 2008-01-13 Example #2 Values exceeding ranges are added to their parent values <?php $date = new DateTime(); $date->setISODate(2008, 2, 7); echo $date->format('Y-m-d') . " "; $date->setISODate(2008, 2, 8); echo $date->format('Y-m-d') . " "; $date->setISODate(2008, 53, 7); echo $date->format('Y-m-d') . " "; ?> The above example will output: 2008-01-13 2008-01-14 2009-01-04 Example #3 Finding the month a week is in <?php $date = new DateTime(); $date->setISODate(2008, 14); echo $date->format('n'); ?> The above examples will output: 3 SEE ALSO
DateTime.setDate(3), DateTime.setTime(3). PHP Documentation Group DATETIME.SETISODATE(3)
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