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Bash conditionals: how to “and” expressions? (if [ ! -z $VAR && -e $VAR ])
...$VAR is empty.
Your version does not work because it evaluates to [ -e ]. Now in this case, bash simply checks if the single argument (-e) is a non-empty string.
From the manpage:
test and [ evaluate conditional expressions using a set of rules based on the number of arguments. ...
1 argu...
Hide html horizontal but not vertical scrollbar
...s been the industry's standard dummy text ever since the 1500s, when an unknown printer took a galley of type and scrambled it to make a type specimen book. It has survived not only five centuries, but also the leap into electronic typesetting, remaining essentially unchanged. It was popularised in ...
How to install packages offline?
...env2.
python -m virtualenv myenv2
cd myenv2
source bin/activate
cd -
ls
now you can go to your offline folder where your requirements.txt and tranferred_packages folder are in there. download the packages with following code and put all of them to tranferred_packages folder.
pip download -r requ...
Check whether a variable is a string in Ruby
...
Without knowing the question's intent, I'd say for most real-world programming situations, is_a? is actually the more appropriate idiom to use (and often a duck-typing check like Andrew Grimm mentions is even better). A strict class c...
TypeScript or JavaScript type casting
...
Now, I see that in in doc, referred to as Type Assertions in section 4.13.
– Klaus Nji
Nov 3 '12 at 12:27
...
How to send email to multiple recipients using python smtplib?
...m to send an email from a python script and with this piece of code, i can now send the email.
– fear_matrix
Jul 14 '15 at 10:36
7
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How to split one string into multiple strings separated by at least one space in bash shell?
...individual elements:
sentence="this is a story"
stringarray=($sentence)
now you can access individual elements directly (it starts with 0):
echo ${stringarray[0]}
or convert back to string in order to loop:
for i in "${stringarray[@]}"
do
:
# do whatever on $i
done
Of course looping thr...
In MVVM should the ViewModel or Model implement INotifyPropertyChanged?
...view-model somehow. Honest question, I'm dealing with this conundrum right now.
– Roger Lipscombe
Jan 18 '10 at 17:15
4
...
Maven in Eclipse: step by step installation [closed]
...2e/releases"
or
http://download.eclipse.org/technology/m2e/milestones/1.0
Now click OK
After that installation would be started.
Way 2: Another way to install Maven plug-in for Eclipse by "Eclipse Marketplace":
Open Eclipse
Go to Help -> Eclipse Marketplace
Search by Maven
Click "Install" b...
NoSql vs Relational database
... big advantages:
Strong mathematical basis.
Declarative syntax.
A well-known language in Structured Query Language (SQL).
Those haven't gone away.
It's a mistake to think about this as an either/or argument. NoSQL is an alternative that people need to consider when it fits, that's all.
Docum...