Now use a text editor such as vi or pico but not gui

stands for user john's home directory.
Now use a text editor, such as
vi
or
pico
, but not GUI based text editors, to create a
C program hello.c that outputs
Hello World!
Name the file
hello.c
and save it in directory
hello
.
Compile your program with command
gcc hello.c
. This command compiles the
source code
hello.c
into an object file
hello.o
, and then links the object code with
the necessary library routines to form a complete, executable, program named
a.out
.
Now list your current directory with command
ls -lt
. You will see your original
source code
hello.c
, possibly the object code
hello.o
and the executable
a.out
.
Now run the program
a.out
by typing the command
./a.out
. Note the dot in this
command, which indicates that the program
a.out
is under the current directory,
denoted by a single dot ".". You should see the output
Hello world!
In C, we use functions such as
printf
,
putchar
, etc., to send output to the standard
output, which is similar to
System.out.print
in Java and
cout <<
in C++. To use
these functions, we must include the standard header file
<stdio.h>
(standard I/O
header file).
To see how to use the functions such as
printf
, type the manual command:
man -s
3 printf
on the terminal. In this command, the option "
-s 3
" means section 3 of the
manual. All standard C functions are grouped under section 3.
Try to display the manual page for the standard C function
exit
too.
3. Create a C source code file
getFullName.c
that prompts the user (using
fgets
) to
enter his full name. Compile and execute it.
Note: since the above program is a new program, you should place it inside a
different directory, such as
~/lab02/getFullName
. In future exercises, each new
program should be placed in a separate directory.