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What's the difference between Perl's backticks, system, and exec?
...It never returns true, because if the command is found it never returns at all.
There is also no point in returning STDOUT, STDERR or exit status of the command.
You can find documentation about it in perlfunc,
because it is a function.
system
executes a command and your Perl script is con...
How can I let a table's body scroll but keep its head fixed in place?
...in a set size. I need the headers at the top of the table to stay there at all times but I also need the body of the table to scroll no matter how many rows are added to the table. Think a mini version of excel. This seems like a simple task but almost every solution I have found on the web has some...
How to undo “git commit --amend” done instead of “git commit”
I accidentally amended my previous commit. The commit should have been separate to keep history of the changes I made to a particular file.
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Is file append atomic in UNIX?
...ger (linux seems to have it set to 4096).
This assume that you're talking all fully POSIX-compliant components. For instance, this isn't true on NFS.
But assuming you write to a log file you opened in 'O_APPEND' mode and keep your lines (including newline) under 'PIPE_BUF' bytes long, you should ...
What is a serialVersionUID and why should I use it?
...ization runtime associates with each serializable class a version number, called a serialVersionUID, which is used during deserialization to verify that the sender and receiver of a serialized object have loaded classes for that object that are compatible with respect to serialization. If the receiv...
How do I force a DIV block to extend to the bottom of a page even if it has no content?
In the markup shown below, I'm trying to get the content div to stretch all the way to the bottom of the page but it's only stretching if there's content to display. The reason I want to do this is so the vertical border still appears down the page even if there isn't any content to display.
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Stretch and scale CSS background
... background-size: cover;
}
cover means stretching the image either vertically or horizontally so it never tiles/repeats.
That would work for Safari 3 (or later), Chrome, Opera 10+, Firefox 3.6+, and Internet Explorer 9 (or later).
For it to work with lower verions of Internet Explorer, try th...
Read specific columns from a csv file with csv module?
...is spectacular for dealing with csv files, and the following code would be all you need to read a csv and save an entire column into a variable:
import pandas as pd
df = pd.read_csv(csv_file)
saved_column = df.column_name #you can also use df['column_name']
so if you wanted to save all of the inf...
Ignore fields from Java object dynamically while sending as JSON from Spring MVC
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Can I do it dynamically? Not in POJO? Can I do it in my Controller class?
– iCode
Apr 16 '14 at 6:36
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Can I run multiple versions of Google Chrome on the same machine? (Mac or Windows)
...
In the comments, I mentioned a step-by-step method to easily install multiple Chrome versions, side-by-side. This answer quotes my original answer, and includes a script which does the job for you.
Quoted from: section 7 of Cross-browser testing: All major browsers on ONE machine:
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