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Test for non-zero length string in Bash: [ -n “$var” ] or [ “$var” ]
I've seen Bash scripts test for a non-zero length string in two different ways. Most scripts use the -n option:
6 Answers...
Summarizing multiple columns with dplyr? [duplicate]
... <dbl>
#> 1 1 3.08 2.98 2.98 2.91
#> 2 2 3.03 3.04 2.97 2.87
#> 3 3 2.85 2.95 2.95 3.06
If you want to summarize only certain columns, use summarise_at or summarise_if functions.
Alternatively, the purrrlyr package provides the same functionality:
library(purr...
How to stop an unstoppable zombie job on Jenkins without restarting the server?
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LoganMzz
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answered Oct 10 '14 at 18:48
ZahraZahra
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What parameters should I use in a Google Maps URL to go to a lat-lon?
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xomenaxomena
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How to obtain the start time and end time of a day?
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14 Answers
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how do I query sql for a latest record date for each user
I have a table that is a collection entries as to when a user was logged on.
22 Answers
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Should a retrieval method return 'null' or throw an exception when it can't produce the return value
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487
If you are always expecting to find a value then throw the exception if it is missing. The ex...
Get property value from string using reflection
...Ed S.Ed S.
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proper way to sudo over ssh
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245
Another way is to use the -t switch to ssh:
ssh -t user@server "sudo script"
See man ssh:
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Why there is no ForEach extension method on IEnumerable?
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edited Sep 4 '12 at 13:41
Maslow
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