veryvery simply question about complieing c

[jjbin]

I follow a info from a page in Ubuntu to
first run my C

here is the expl

Now you need to open first.c file

sudo gedit first.c

add the following lines save and exit the file


#include <stdio.h>

int main()
{
printf("hello world\n");
return 0;
}


Firstly compile the code using the following command

cc -c first.c

that would produce an object file you may need to add to the library.

then create an executable using the following command

cc -o first first.c

Now run this executable using the following command

./first

Output should show as follows

Hello, world

I am vervvery beginner
who can explain to me
why at last should type ./first

what about this command
"cc -o first first.c"

or somebody could give me a more
suitable place to ask for the newie

[x33a]

1) ./first

here, first is the executable, like an exe file in windows.

./ specifies to look for the exec in the current directory, otherwise you'll have to add it to the system PATH.

2) cc -o first first.c

means to place the output of the compiled file into first, the executable file.

look into
man gcc

for all the switches and other compiler specific options.