Command Line Argument

Applications Programming
1

Hi,

I have a very simple C program which will run in UNIX. When i am passing * as the command line argument, i am gettig the below output.

Program:
#include <stdio.h>
#include "mylibrary.h"

int **environ;

int main(int argc,char *argv[])
{
int i;
printf("\nHello World");
printf("\nNumber of arguments: %d\n",argc);

    for\(i=0;i&lt;argc;i\+\+\)
    \{
            printf\("\\nArgument \# %d is: %s\\n",i,argv[i]\);
     \}

    return 1;

}

Compile:
cc hello.c -o hello

Run:
./hello *

Output:
Hello World
Number of arguments: 5

Argument # 0 is: ./hello

Argument # 1 is: hello

Argument # 2 is: hello.c

Argument # 3 is: mylibrary.h

Can somebody please explain me what is the exact reason of this output.

Thanks
Sudipta.

2

The shell is expanding the asterisk to the files in the current directory. Similar expansion happens with ?, shell variables, and character classes '[..]'. Standard behavior for all proper UNIX shells.

Use '*' instead if you want to pass a literal asterisk.

3

OK Thanks a lot. Now i understood what is the reason of the output.

---------- Post updated at 04:19 AM ---------- Previous update was at 01:00 AM ----------

Just want to share one information this technique is known as Glob Programming. You can get the information in wikipedia. Here comes the link:
http://en.wikipedia.org/wiki/Glob_\(programming\)