How do I input an argument in the main?

Applications Programming
1

----------C program-----------------------------
include <stdio.h>

int main( int argc, char *argv[] )
{
int i;
for( i=0; i<argc; i++ )
printf("%\n", argv[i]);
return 0;
}
I wrote the C program above 'print.c'.
Then, I compiled. (gcc -o print.o print.c)

In unix, I've tried to execute it. (./print.o)

How do I input an argument in the main?

2

Don't call the output print.o. print.o would be the default name for an object module. You would probably call the linked executable "print". At least that's a better choice than print.o. But "print" is also the name of a ksh built-in...

Anyway to run it with args just do...

./print arg1 arg2 arg3

And finally your format string in the printf call needs a little work. It's %s to print a string.

3

Try the following program. Put it in a file called "howdy.c".

#include <stdio.h>

int main( int argc, char *argv[] )
{
if (!argc)
{
printf("Missing input argument!\n");
printf("Usage: howdy %1\n");
return 1;
}

printf("Well howdy there %s! YeeHaw!!!\n", argv[1]);
return 0;
}

To do a simple compile, type "gcc howdy.c -o howdy"
After it's compiled (assuming you have no errors), give it a run similiar to the following:

./howdy DUDE

(But try substituting something other than dude...)

Thanks!
---> Kelsey