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How to print last two columns using awk
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Now you're printing "field-OFS-tab-OFS-field". It should be awk '{print $(NF-1) "\t" $NF}' file or awk '{print $(NF-1), $NF}' file or awk 'BEGIN{OFS="\t"} {print $(NF-1), $NF}' file.
– Paused until furth...
MySQL Results as comma separated list
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Now only I came across this situation and found some more interesting features around GROUP_CONCAT. I hope these details will make you feel interesting.
simple GROUP_CONCAT
SELECT GROUP_CONCAT(TaskName)
FROM Tasks;
Resul...
Does pandas iterrows have performance issues?
...a custom Cython routine is usually too complicated, so let's skip that for now.
1) Vectorization is ALWAYS, ALWAYS the first and best choice. However, there is a small set of cases (usually involving a recurrence) which cannot be vectorized in obvious ways. Furthermore, on a smallish DataFrame, it ...
【内核源码】linux UDP实现 - 操作系统(内核) - 清泛网 - 专注C/C++及内核技术
...elimited("cork app bug 2\n");
err = -EINVAL;
goto out;
}
/*
* Now cork the socket to pend data.
*/
fl4 = &inet->cork.fl.u.ip4;
fl4->daddr = daddr;
fl4->saddr = saddr;
fl4->fl4_dport = dport;
fl4->fl4_sport = inet->inet_sport;
up->pending = AF_INET; //标记，表明正在...
Google Guava vs. Apache Commons [closed]
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In my opinion the better choice is Guava (formerly known as Google collections):
it's more modern (has generics)
it absolutely follows the Collections API requirements
it's actively maintained
CacheBuilder and it's predecessor MapMaker are just plain awesome
Apache Commons...
Is null an Object?
...inheritance not only for interfaces but for classes as well. Which we all know is not possible for us application programmers.
(2) The null literal might be imagined as a variable being defined as:
JVM_global final null_type null = new null_type();
Note also JLS 3.9:
A variety of character se...
postgresql port confusion 5433 or 5432?
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/etc/services is only advisory, it's a listing of well-known ports. It doesn't mean that anything is actually running on that port or that the named service will run on that port.
In PostgreSQL's case it's typical to use port 5432 if it is available. If it isn't, most installers ...
My attempt at value initialization is interpreted as a function declaration, and why doesn't A a(())
Among the many things Stack Overflow has taught me is what is known as the "most vexing parse", which is classically demonstrated with a line such as
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How to randomly select rows in SQL?
...problem where you are working with a large result set (not the question I know).
Selecting Rows Randomly from a Large Table
http://msdn.microsoft.com/en-us/library/cc441928.aspx
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Multiprocessing - Pipe vs Queue
...ue() accounts for tasks when queue.task_done() is called (it doesn't even know about the specific task, it just counts unfinished tasks in the queue), so that queue.join() knows the work is finished.
The code for each at bottom of this answer...
mpenning@mpenning-T61:~$ python multi_pipe.py
Sendi...