Most of the people compile the C programs without this option .. Please try to avoid it.. That said, the mentioned option allows you to know the compiler warnings, dont skip it . ( I know in my previous post I didnt do it, but deliberately to show the mistake 🙂 )

compile.c look like this:

# include <stdio.h>

int main ()
{

	printf ("\n I was told to compile ");
}




When I compile it with "-Wall" option I see:

[hchiramm@humbles-lap C-Pgm]$ gcc -Wall -c compile.c 
compile.c: In function ‘main’:
compile.c:7:1: warning: control reaches end of non-void function [-Wreturn-type]
 }


Why it so ? Any guess ?

hmmm.. I defined the function main() that it return "int", but I didnt do so.. Isnt it the same reason.. Lets try:

[hchiramm@humbles-lap C-Pgm]$ cat compile.c
# include <stdio.h>

int main ()
{

	printf ("\n I was told to compile ");
	return 0;
}


[hchiramm@humbles-lap C-Pgm]$ gcc -Wall -c compile.c 
[hchiramm@humbles-lap C-Pgm]$

No Errors! .. Thats good.. so please remember to compile your program with "-Wall" option..