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How to check if a symlink exists
I'm trying to check if a symlink exists in bash. Here's what I've tried.
8 Answers
8
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Check if directory mounted with bash
.... From a shell script, you can check for the mount point with grep and an if-statement:
if mount | grep /mnt/md0 > /dev/null; then
echo "yay"
else
echo "nay"
fi
In my example, the if-statement is checking the exit code of grep, which indicates if there was a match. Since I don't want...
Creating a new directory in C
I want to write a program that checks for the existence of a directory; if that directory does not exist then it creates the directory and a log file inside of it, but if the directory already exists, then it just creates a new log file in that folder.
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How to select rows with one or more nulls from a pandas DataFrame without listing columns explicitly
I have a dataframe with ~300K rows and ~40 columns.
I want to find out if any rows contain null values - and put these 'null'-rows into a separate dataframe so that I could explore them easily.
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Why `null >= 0 && null
I had to write a routine that increments the value of a variable by 1 if its type is number and assigns 0 to the variable if not, where the variable is initially null or undefined .
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List comprehension with if statement
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You got the order wrong. The if should be after the for (unless it is in an if-else ternary operator)
[y for y in a if y not in b]
This would work however:
[y if y not in b else other_value for y in a]
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Remove a marker from a GoogleMap
...r (MarkerOptions options)
So when you add a marker to a GoogleMap by specifying the options for the marker, you should save the Marker object that is returned (instead of the MarkerOptions object that you used to create it). This object allows you to change the marker state later on. When you ar...
Copy folder recursively in node.js
... answered Dec 9 '12 at 9:25
shift66shift66
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How to commit changes to a new branch
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how about if I already tracked a files and I want to switch to a new branch add those files to the newly created branch?
– ass-king some question
Jun 19 at 2:47
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How to generate a random number between a and b in Ruby?
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This is a really bad idea, especially if your a and b are of unknown sizes. Try (100000000000000000..100000000000000).to_a.sample and see what I mean : )
– pixelearth
Sep 16 '11 at 22:06
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