Category Archives: Programming

Some stuff about programming. Sharing random experiences and code I wrote

Allocating arrays of function pointers in C

Dynamically allocate array of 2 pointers to functions returning int and taking no argument.

int test1() {printf "test1"; return 0;}
int test2() {printf "test2"; return 0;}

int main(int argc, char* argv[]) 
{
  int (*(*f_arr))() = malloc(sizeof(int (*)()) * 2);
  f_arr[0] = &test1;
  f_arr[1] = &test1;
}

int test1() {printf "test1"; return 0;}

int test2() {printf "test2"; return 0;}

int main(int argc, char* argv[])

{

int (*(*f_arr))() = malloc(sizeof(int (*)()) * 2);

f_arr[0] = &test1;

f_arr[1] = &test1;

}

Statically allocate array of 2 pointers to functions returning int and taking no argument.

int test1() {printf "test1"; return 0;}
int test2() {printf "test2"; return 0;}

int main(int argc, char* argv[]) 
{
	int (*f_arr[2])() = {test1, test2};
	return testRunner(f_arr, 2);
}

int test1() {printf "test1"; return 0;}

int test2() {printf "test2"; return 0;}

int main(int argc, char* argv[])

{

int (*f_arr[2])() = {test1, test2};

return testRunner(f_arr, 2);

}

How to use eval command in bash?

Command eval is builtin shell builtin, part of POSIX. In practice, eval takes a string as argument and evaluates that string as if you would typed it if it was… Read more »

C# snippet : JSONify object

One of my most favorite C# snippet is following oneliner useful when quick debugging or checking on something is needed.

 Newtonsoft.Json.JsonConvert.SerializeObject(new {foo = "bar"))

1	Newtonsoft.Json.JsonConvert.SerializeObject(new {foo = "bar"))

Which returns String containing JSON representation of arbitrary C#… Read more »

How to create and fill database from shell script

TLDR Make sure MySQL is discoverable from your path Run:

mysql -uroot -ppassword  < createDatabase.sql > outputCreate.log

1	mysql -uroot -ppassword < createDatabase.sql > outputCreate.log

to run createDatabase.sql as user root with password password More detailed version Recently I was working on a little… Read more »

You must set this property to a non-null value of type ‘System.Int64’.

Recently I encountered following problem in C#.

System.InvalidOperationException was unhandled by user code
Message: The 'Id' property on 'SomeDAO' could not be set to a 'System.Decimal' value. You must set this property to a non-null value of type 'System.Int64'.

1 2	System.InvalidOperationException was unhandled by user code Message: The 'Id' property on 'SomeDAO' could not be set to a 'System.Decimal' value. You must set this property to a non-null value of type 'System.Int64'.

This error is pretty obvious in certain context, but if you don’t read it carefully enough, in some situations you might get… Read more »

Category Archives: Programming

Allocating arrays of function pointers in C

How to use eval command in bash?

C# snippet : JSONify object

How to create and fill database from shell script

You must set this property to a non-null value of type ‘System.Int64’.

Javascript gotcha ! (if you come from Python)

What is difference between atan and atan2 ?

Directional mean in python

How to unit test your python modules