> echo '#include <stdio.h>' > hello.c
> echo 'main() { printf("Hello world!\n"); }' >> hello.c
> gcc -o hello hello.c
> ./hello
Hello world!
Above is the standard first lesson of the C programming language. The first two lines compose a program in to a file called hello.c. The third line invokes a compiler which reads that file and turns it in to a computer program. The fourth line executes that program, and you see what the program does on the fifth line.
It may look complicated, but it is actually pretty simple:
> cat hello.c
#include <stdio.h>
main() { printf("Hello world!\n"); }
That first line "concatenates" the contents of hello.c to the terminal. The first line of the program includes the "standard input/output" library which has functions for inputting and outputting data. The second line defines a function called "main" which consists entirely of a call to the printf, or "formatted print" function from the standard input-output library to print the string "Hello World!" and a carriage-return, marked by the "\n." Once compiled in to a program called "hello," the main function is called when you run the hello program.
With a few paragraphs of text, I have communicated to you a very rudimentary understanding of the C programming language. My day job has a lot of of typing things in to computers so that they can or will do particular things. Since I get a lot of practice, I'm pretty good at the nuanced subtleties of grammar, and I know a number of ways to express the same intentions to get my point across. My employer keeps giving me more money to tell computers what to do.
While communicating with computers brings gratification, it is all the more fun and challenging to communicate with humans. I try to get some practice at it; Welcome to one of my testing grounds. Watch your step. I hope to get some ideas to communicate to you all, so that you'll come away with something even more rewarding than a rudimentary understanding of the C programming language.
Now, I hand the prompt to you ...
> cat purpose.html > cd /journal/2001/ > fetch "legacy web site"