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How to check if a symlink exists
... the GNU manpage, -h is identical to -L, but according to the BSD manpage, it should not be used:
-h file True if file exists and is a symbolic link. This operator is retained for compatibility with previous versions of this program. Do not rely on its existence; use -L instead.
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Opposite of %in%: exclude rows with values specified in a vector
... use
`%not in%` <- function (x, table) is.na(match(x, table, nomatch=NA_integer_))
Another way is:
function (x, table) match(x, table, nomatch = 0L) == 0L
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package R does not exist
I'm getting the dreaded package R does not exist, it's killing me.
The code is fine I have apps in the market running the code.
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How to run `rails generate scaffold` when the model already exists?
... controller scaffold for your model, see scaffold_controller. Just for clarity, here's the description on that:
Stubs out a scaffolded controller and its views. Pass the model name,
either CamelCased or under_scored, and a list of views as arguments.
The controller name is retrieved ...
How to take a screenshot programmatically on iOS
...n] respondsToSelector:@selector(scale)]) {
UIGraphicsBeginImageContextWithOptions(self.window.bounds.size, NO, [UIScreen mainScreen].scale);
} else {
UIGraphicsBeginImageContext(self.window.bounds.size);
}
[self.window.layer renderInContext:UIGraphicsGetCurrentContext()];
UIImage *image = U...
PHP 5.4 Call-time pass-by-reference - Easy fix available?
Is there any way to easily fix this issue or do I really need to rewrite all the legacy code?
3 Answers
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Find all files in a directory with extension .txt in Python
... os.listdir:
import os
for file in os.listdir("/mydir"):
if file.endswith(".txt"):
print(os.path.join("/mydir", file))
or if you want to traverse directory, use os.walk:
import os
for root, dirs, files in os.walk("/mydir"):
for file in files:
if file.endswith(".txt"):
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Returning JSON from a PHP Script
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While you're usually fine without it, you can and should set the Content-Type header:
<?php
$data = /** whatever you're serializing **/;
header('Content-Type: application/json');
echo json_encode($data);
If I'm not using a particular framework, I u...
Is there a way to get version from package.json in nodejs code?
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I found that the following code fragment worked best for me. Since it uses require to load the package.json, it works regardless the current working directory.
var pjson = require('./package.json');
console.log(pjson.version);
A warning, courtesy of @Pathogen:
Doing this with Browseri...
Rails DB Migration - How To Drop a Table?
... table that I thought I was going to need, but now no longer plan on using it. How should I remove that table?
22 Answers
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