You got it.
You probably already know the best way to learn is to log on and play around on the computer. You're right if only two people are on (you and the admin) that you can't really test "who" very well. In that case, you can create a little test file, and do some experiments, such as:
I used "echo" to make the test.txt file. If you know how to use a Unix editor, of course use the editor instead.
With the test file, you can try out different sort options, as you are already doing with -r option.
Quote:
I am not really sure why this order of who and sort works.
Is it because you need to run who first so the sort takes
the input from the other command (who)?
Yes, that is exactly right! "who" produces the output, the "raw materials". The output from "who" enters the pipe. On the other side of the pipe, "sort" reads its input. The output from "sort" is what you finally see.
"who" does not expect any input, so it would not make sense to put "who" on the right-hand side of the pipe. "sort" HAS to have input, or have a file specified for it to operate upon. In the examples above, I showed three simple ways sort can get input (sort file, | sort, and sort < file).
Quote:
P.S. I am doing a small grading program for this same lab as well.
I will post my results later tonight. Didn't post here because I had
not yet tried anything. Should I open a new thread or post here?
Hello all,
I have a test file that has the format:
.....
O
3.694950 -.895050 1.480000
O
5.485050 .895050 1.480000
Ti
-4.590000 4.590000 2.960000
Ti
-2.295000 ... (5 Replies)
hello folks
i have a file that have data like
/test/aa/123
/test/aa/xyz
/test/bb/xyz
/test/bb/123
in above lines i just wants to grep "aa" and "bb".
Thanks,
Bash (4 Replies)
can someone help me in the awk part...little confuse on that part.
The problem is this: what input each utility gets and what it does with data and what output is provides to the next utility)
history | awk '{a++}END{for(i in a){print a " " i}}' | sort -rn | grep '^'
Thanks (4 Replies)
Hi Expert,
Kindly request for your expertise in this matter.
I have below output:
12.125.124.173,xx1.common.com
12.125.124.174,xx2.common.com
12.125.124.175,xx3.common.com
12.125.124.176,
12.125.124.177,
12.125.124.178,
12.125.124.179,xx4.common.com
12.125.124.180,xx5.common.com... (8 Replies)
for example, I have a text file in random content inside, maybe something like this.
234234
54654
123134
467456
24234234
7867867
23424
568567if I run this command
cat "filename.txt" | sort -n | grep "^467456$" -A 1 -B 1the result is
234234
467456
568567is it possible to do this command... (2 Replies)
Hi,
Trying to sort grep result based on timestamp of the filename.
I have the following result and want to sort them on timestampgrep -i 'ERROR' *log*2013*
s_m_xxx_xxx_xxx_xxx_xxxx.log.20130906092431:TRANSF_1_1_1> DBG_21216 Finished transformations for Source Qualifier . Total errors ... (5 Replies)
1. The problem statement, all variables and given/known data:
So i'll probably get told off for this but I have a few problems and rather than clog up the whole forum I'll post them here. Please bare in mind I am a complete novice when it comes to all this and so if you help please treat me like a... (4 Replies)
1. The problem statement, all variables and given/known data:
Please bare in mind I am a complete novice to this and have very very basic knowledge so please keep any answers as simple as possible and explain in terms I will understand ahha :):)
I have a text file of names and test scores... (1 Reply)
Hi Gurus,
I have two big files. I need to compare the different. currently, I am using
sort file1 > file1_temp;
sort file2 > file2_tmp
diff file1_tmp file2_tmp
I can use command
grep -v -f file1 file2
just wondering which way is fast to compare two big files.
Thanks... (4 Replies)
Discussion started by: ken6503
4 Replies
LEARN ABOUT PHP
mongocollection.aggregatecursor
MONGOCOLLECTION.AGGREGATECURSOR(3) 1 MONGOCOLLECTION.AGGREGATECURSOR(3)MongoCollection::aggregateCursor - Execute an aggregation pipeline command and retrieve results through a cursor
SYNOPSIS
public MongoCommandCursor MongoCollection::aggregateCursor (array $command, [array $options])
DESCRIPTION
With this method you can execute Aggregation Framework pipelines and retrieve the results through a cursor, instead of getting just one
document back as you would with MongoCollection::aggregate. This method returns a MongoCommandCursor object. This cursor object implements
the Iterator interface just like the MongoCursor objects that are returned by the MongoCollection::find method.
Note
The resulting MongoCommandCursor will inherit this collection's read preference. MongoCommandCursor::setReadPreference may be used
to change the read preference before iterating on the cursor.
PARAMETERS
o $pipeline
- The Aggregation Framework pipeline to execute.
o $options
-Options for the aggregation command. Valid options include:
o "allowDiskUse"Allow aggregation stages to write to temporary files
o "cursor" It is possible to configure how many initial documents the server should return with the first result set. The
default initial batch size is 101. You can change it by adding the batchSize option:
<?php
$collection->aggregateCursor(
$pipeline,
[ "cursor" => [ "batchSize" => 4 ] ]
);
MongoCommandCursor::batchSize method on the returned MongoCommandCursor object.
o "explain" Return information on the processing of the pipeline. This option may cause the command to return a result docu-
ment that is unsuitable for constructing a MongoCommandCursor. If you need to use this option, you should consider using
MongoCollection::aggregate.
o "maxTimeMS"Specifies a cumulative time limit in milliseconds for processing the operation (does not include idle time). If
the operation is not completed within the timeout period, a MongoExecutionTimeoutException will be thrown.
RETURN VALUES
Returns a MongoCommandCursor object. Because this implements the Iterator interface you can iterate over each of the results as returned
by the command query. The MongoCommandCursor also implements the MongoCursorInterface interface which adds the MongoCommandCursor::batch-
Size, MongoCommandCursor::dead, MongoCommandCursor::info methods.
EXAMPLES
Example #1
MongoCollection.aggregateCursor(3) example
Finding all of the distinct values for a key.
<?php
$m = new MongoClient;
$db = $m->test;
$people = $db->people;
$people->drop();
$people->insert(array("name" => "Joe", "points" => 4));
$people->insert(array("name" => "Molly", "points" => 43));
$people->insert(array("name" => "Sally", "points" => 22));
$people->insert(array("name" => "Joe", "points" => 22));
$people->insert(array("name" => "Molly", "points" => 87));
$ages = $people->aggregateCursor( [
[ '$group' => [ '_id' => '$name', 'points' => [ '$sum' => '$points' ] ] ],
[ '$sort' => [ 'points' => -1 ] ],
] );
foreach ($ages as $person) {
echo "{$person['_id']}: {$person['points']}
";
}
?>
The above example will output something similar to:
Joe: 26 Sally: 22
Example #2
MongoCollection.aggregateCursor(3) example with different initial batch size
Finding all of the distinct values for a key.
<?php
$m = new MongoClient;
$db = $m->test;
$people = $db->people;
$people->drop();
/* Insert some sample data */
$people->insert(array("name" => "Joe", "points" => 4));
$people->insert(array("name" => "Molly", "points" => 43));
$people->insert(array("name" => "Sally", "points" => 22));
$people->insert(array("name" => "Joe", "points" => 22));
$people->insert(array("name" => "Molly", "points" => 87));
/* Run the command cursor */
$ages = $people->aggregateCursor(
[
[ '$group' => [ '_id' => '$name', 'points' => [ '$sum' => '$points' ] ] ],
[ '$sort' => [ 'points' => -1 ] ],
],
[ "cursor" => [ "batchSize" => 4 ] ]
);
foreach ($ages as $person) {
echo "{$person['_id']}: {$person['points']}
";
}
?>
The above example will output something similar to:
Joe: 26 Sally: 22
SEE ALSO
MongoDB::command, MongoCommandCursor, MongoCommandCursor::batchSize, MongoCollection::aggregate, The MongoDB aggregation framework.
PHP Documentation Group MONGOCOLLECTION.AGGREGATECURSOR(3)