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Passing parameters to a Bash function
...s of declaring a function. I prefer the second approach.
function function_name {
command...
}
or
function_name () {
command...
}
To call a function with arguments:
function_name "$arg1" "$arg2"
The function refers to passed arguments by their position (not by name), that is $1, $2...
Which is faster: while(1) or while(2)?
...intel with an optimization flag):
With -O0:
.file "main.c"
.intel_syntax noprefix
.def __main; .scl 2; .type 32; .endef
.text
.globl main
.def main; .scl 2; .type 32; .endef
.seh_proc main
main:
push rbp
.seh_pushreg rbp
mov rbp,...
jQuery Ajax File Upload
...Data.append("file", this.file, this.getName());
formData.append("upload_file", true);
$.ajax({
type: "POST",
url: "script",
xhr: function () {
var myXhr = $.ajaxSettings.xhr();
if (myXhr.upload) {
myXhr.upload.addEventListener(...
Convert a row of a data frame to vector
...u have to be careful if your row contains a factor. Here is an example:
df_1 = data.frame(V1 = factor(11:15),
V2 = 21:25)
df_1[1,] %>% as.numeric() # you expect 11 21 but it returns
[1] 1 21
Here is another example (by default data.frame() converts characters to factors)
d...
What is the JavaScript equivalent of var_dump or print_r in PHP? [duplicate]
...e of object in JavaScript (for debugging). Is there anything similar to var_dump in PHP?
9 Answers
...
How to convert CFStringRef to NSString?
...e using ARC, the new casting syntax is as follows:
NSString *aNSString = (__bridge NSString *)aCFString;
works as well. The key thing to note is that CoreFoundation will often return objects with +1 reference counts, meaning that they need to be released (all CF[Type]Create format functions do th...
In Python, how can you load YAML mappings as OrderedDicts?
...rary code this is a bad idea. Also, it doesn't directly work with yaml.safe_load().
Fortunately, the solution can be improved without much effort:
import yaml
from collections import OrderedDict
def ordered_load(stream, Loader=yaml.Loader, object_pairs_hook=OrderedDict):
class OrderedLoader(L...
What is “:-!!” in C code?
...ld.
The macro is somewhat misnamed; it should be something more like BUILD_BUG_OR_ZERO, rather than ...ON_ZERO. (There have been occasional discussions about whether this is a confusing name.)
You should read the expression like this:
sizeof(struct { int: -!!(e); }))
(e): Compute expression e....
How do I execute inserts and updates in an Alembic upgrade script?
... other forms.
Note that Alembic provides some basic data functions: op.bulk_insert() and op.execute(). If the operations are fairly minimal, use those. If the migration requires relationships or other complex interactions, I prefer to use the full power of models and sessions as described below.
T...
How to convert An NSInteger to an int?
...endently of whether you are building for a 32-bit or a 64-bit system.
#if __LP64__ || TARGET_OS_EMBEDDED || TARGET_OS_IPHONE || TARGET_OS_WIN32 || NS_BUILD_32_LIKE_64
typedef long NSInteger;
#else
typedef int NSInteger;
#endif
You can use NSInteger any place you use an int without converting it....