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Check if a Windows service exists and delete in PowerShell
...$ServiceName.
# Returns a boolean $True or $False.
Function ServiceExists([string] $ServiceName) {
[bool] $Return = $False
# If you use just "Get-Service $ServiceName", it will return an error if
# the service didn't exist. Trick Get-Service to return an array of
# Services, but o...
Is char signed or unsigned by default?
In the book "Complete Reference of C" it is mentioned that char is by default unsigned.
7 Answers
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What are copy elision and return value optimization?
....
Copy elision is an optimization implemented by most compilers to prevent extra (potentially expensive) copies in certain situations. It makes returning by value or pass-by-value feasible in practice (restrictions apply).
It's the only form of optimization that elides (ha!) the as-if rule - copy el...
How to use GROUP_CONCAT in a CONCAT in MySQL
.... I always use this separator, because it's impossible to find it inside a string, therefor it's unique.
There is no problem having two A's, you identify only the value. Or you can have one more colum, with the letter, which is even better.
Like this :
SELECT id,GROUP_CONCAT(DISTINCT(name)), GROUP_...
How do I remove the first characters of a specific column in a table?
... - 4) AS MyTrimmedColumn
Edit:
To explain, RIGHT takes 2 arguments - the string (or column) to operate on, and the number of characters to return (starting at the "right" side of the string). LEN returns the length of the column data, and we subtract four so that our RIGHT function leaves the lef...
Evil Mode best practice? [closed]
... (message "graphics active")
)
(insert (shell-command-to-string "xsel -o -b"))
)
)
(global-set-key [f8] 'copy-to-clipboard)
(global-set-key [f9] 'paste-from-clipboard)
Obviously, you will have to decide for yourself whether any of these controversial changes are worth it, ...
When saving, how can you check if a field has changed?
...
Really perfect, and do not perform extra query. Thanks a lot !
– Stéphane
Mar 4 '13 at 10:26
29
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How to list the contents of a package using YUM?
...s taken with spacing):
Loaded plugins: fastestmirror
base | 3.6 kB 00:00
extras | 3.4 kB 00:00
updates | 3.4 kB 00:00
(1/4): extras/7/x86_64/primary_db | 166 kB 00:00
(2/4): base/7/x86_64/group_gz | 155 kB 00:00
(3/4): updates/7/x86_64/primary_db | 9.1 MB 00:04
(4/4): base/7/x86_64/primary_db...
What is a lambda expression in C++11?
...n false ; return true ; }()) // i is all whitespace, assuming i is an std::string
– Blacklight Shining
Mar 2 '13 at 1:13
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What character to use to put an item at the end of an alphabetic list?
... here is some code that creates a bunch of folders with all the printables strings in Python so you can test your file manager.
import os
import string
for i in string.printable:
try:
os.mkdir(i)
except OSError:
print('OSError for %s' %(I))
Once you have sorte...