function-calls

What is the difference between a system call and a function call? Is fopen() a system call or a function call? A system call is a call into kernel code, typically performed by executing an interrupt. The interrupt causes the kernel to take over and perform the requested action, then hands control back to the application. This mode switching is the reason that system calls are slower to execute than an equivalent application-level function. fopen is a function from the C library that, internally, performs one or more system calls. Generally, as a C programmer, you rarely need to use system

is there a way to find out, where a function in PHP was called from? example: function epic() { fail(); } function fail() { //at this point, how do i know, that epic() has called this function? } You can use debug_backtrace() . Example: <?php function epic( $a, $b ) { fail( $a . ' ' . $b ); } function fail( $string ) { $backtrace = debug_backtrace(); print_r( $backtrace ); } epic( 'Hello', 'World' ); Output: Array ( [0] => Array ( [file] => /Users/romac/Desktop/test.php [line] => 5 [function] => fail [args] => Array ( [0] => Hello World ) ) [1] => Array ( [file] => /Users/romac/Desktop/test

What is the difference between the following? onClick="javascript: function('value');" onClick="function('value');" When do I use the javascript: before the function call, and why? Can I call the function without using javascript: prefix? Please help me understand the difference. In an element's inline event handler, like onclick , onchange , onsubmit , etc., you do not need the javascript: prefix - the reason you often see it is because people confuse it with the href syntax that I explain below. It doesn't cause an error - I believe it is interpreted as a label - but it is unnecessary. It

I recently switched from Matlab to Python . While converting one of my lengthy codes, I was surprised to find Python being very slow. I profiled and traced the problem with one function hogging up time. This function is being called from various places in my code (being part of other functions which are recursively called). Profiler suggests that 300 calls are made to this function in both Matlab and Python . In short, following codes summarizes the issue at hand: MATLAB The class containing the function: classdef ExampleKernel1 < handle methods (Static) function [kernel] = kernel_2D(M,x,N,y)

Is there a way to call Matlab functions from outside, in particular by the Windows cmd (but also the Linux terminal, LUA-scripts, etc...), WITHOUT opening a new instance of Matlab each time? for example in cmd : matlab -sd myCurrentDirectory -r "function(parameters)" -nodesktop -nosplash -nojvm opens a new instance of Matlab relatively fast and executes my function. Opening and closing of this reduced matlab prompt takes about 2 seconds (without computations) - hence for 4000 executions more than 2 hours. I'd like to avoid this, as the called function is always located in the same workspace.