Category: PROGRAMMING

Wiki page on kernighan & Ritchie indentation style:
K&R style

The Linux kernel coding style documented by Torvalds:
Linux Kernel Coding Style

And finally, a tool to indent your code in the K&R style automatically:
Use Kernighan & Ritchie coding style in C program

There is a tendency among programmers to use memset() immediately after a malloc() or declaring a structure type variable. I find it amusing. Sometimes the structure is of considerable size and may not need memset() which should be called in a case by case basis. Let’s see.

example 1:

MyStruct_t a_struct; /* MyStruct has 5 members out of which we are setting only 2 below */
memset((void*) &a_struct, 0, sizeof(MyStruct_t)); /* required */
a_struct.var1 = x;
a_struct.var2 = y;

In this case memset() is required because we are selectively setting the values of some of the members of the structures and not all. So there is a chance of someone later accessing garbage value.

example 2:

MyStruct_t a_struct; /* MyStruct has 5 members out of which all are being set below */
memset((void*) &a_struct, 0, sizeof(MyStruct_t)); /* not required */
bytes = read(fd, &a_struct, sizeof(MyStruct_t));
if(bytes != sizeof(MyStruct_t)) { /* this check is a must */
	/* log error and return */
}

Here memset() is not required as we are reading in the full size of the struct immediately. The check that follows read() takes care that correct number of bytes are read.

A good old article from Linux Journal on how to create your own self-extracting script:
Bash Self-Extracting Script

Here’s another one:
How to create a self-extracting archive

Modern compilers do a great job in optimizing goto-s. But there was a time people were at war on whether to use goto or not. And before that we used to be taught that goto is evil ;). Here’s a chronicle of what happened once regarding usage of goto-s in the kernel –

Linux: Using goto In Kernel Code