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Select random lines from a file
In a Bash script, I want to pick out N random lines from input file and output to another file.
4 Answers
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Specifying and saving a figure with exact size in pixels
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Matplotlib doesn't work with pixels directly, but rather physical sizes and DPI. If you want to display a figure with a certain pixel size, you need to know the DPI of your monitor. For example this link will detect that for you.
If you have an image of 3841x7195 pixels it is unlikely that you m...
What is the reason for performing a double fork when creating a daemon?
...curious as to why a double fork is necessary. I've scratched around google and found plenty of resources declaring that one is necessary, but not why.
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What's the difference between Perl's backticks, system, and exec?
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exec
executes a command and never returns.
It's like a return statement in a function.
If the command is not found exec returns false.
It never returns true, because if the command is found it never returns at all.
There is also no point ...
What is a semaphore?
...t should let the guests go in sequentially, but when i tried it out, it's random. Eg. Guest 40 came in first before Guest 39. Is there anything we could do to control this?
– TNA
May 31 '14 at 9:12
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What are Runtime.getRuntime().totalMemory() and freeMemory()?
... Runtime.getRuntime().totalMemory() , Runtime.getRuntime().freeMemory() , and Runtime.getRuntime().maxMemory() is.
7 Ans...
mingw-w64 threads: posix vs win32
I'm installing mingw-w64 on Windows and there are two options: win32 threads and posix threads. I know what is the difference between win32 threads and pthreads but I don't understand what is the difference between these two options. I doubt that if I will choose posix threads it will prevent me fro...
What's the difference between hard and soft floating point numbers?
... architecture" This can make sense for a library to be machine-independent and bit-exact (soft float) in accuracy-critical parts and fast (hard float) in parts where small deviations don't matter.
– PhilLab
May 29 '17 at 12:18
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Why do you not use C for your web apps?
...different web servers this morning when I came across G-WAN . As I understand, its a web server written in C and you have to make use of it by writing your websites/webapps in C. One clear benefit is speed as the G-WAN site suggests.
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How to differ sessions in browser-tabs?
In a web-application implemented in java using JSP and Servlets; if I store information in the user session, this information is shared from all the tabs from the same browser. How to differ sessions in the browser-tabs?
In this example:
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