Executing command line options

Safia · #1 (**permalink**) 06-26-2002

Can someone please tell me how to modify/add to this code so that it recognizes UNIX command options (all beginning with "-") and executes the command with options?

Code:

#include<stdio.h>
#include<stdlib.h>

int main(int argc, char *argv[])
{

     int i;

    system("stty -echo");

    for(i=1; i<argc; i++)
    {
        printf("The command %s is executed.\n", argv[i]);
        system(argv[i]);
     }

    system("stty echo");
    return 0;
}

linuxpenguin · #2 (**permalink**) 07-01-2002

Hi Safia,

I think you will have to prepare a string of the unix command first and then pass this string to the system function. This string manipulation should take care of the "-" sign. I think you can also try ftok.

Hope this hints you to the solution.

hell666 · #3 (**permalink**) 07-02-2002

There's a function called getopt(), check to see if this function is supported in your compiler, this will help you.

sharuvman · #4 (**permalink**) 07-03-2002

Can you try this one ??
#include "stdio.h"
#include "stdlib.h"
#include "string.h"

void main(int argc, char **argv)
{
char str[30];
if (argv[2][0] == '-')
{
strcpy(str,argv[1]);
strcat(str," ");
strcat(str,argv[2]);
system (str);
}

}//end of main

or

void main(int argc, char **argv)
{
system(argv[1]);
}

for second case, you need to give input as say "ls -l" within double quotes.
You can have any combination for this.
Like let us assume "a.out" is the binary then

./a.out "who | wc -l" also works for the second option.,....

bye,
sharath

hell666 · #5 (**permalink**) 07-03-2002

>void main(int argc, char **argv)
void main() is wrong. main() should return a value.

sharuvman · #6 (**permalink**) 07-03-2002

If main is not intended to return anything.......we must have its return type "void".

You can compile the source code using ansi compliance,

bye,
sharath

hell666 · #7 (**permalink**) 07-04-2002

ANSI C says 'int main()'. Ofcourse, to avoid compiler warnings you can use 'void main()', but that is incorrect. The OS might be wanting a return value from the terminated program, and when you are not returning any value to it, a junk value might be returned to your OS, and the results could be unpredictable.

See this

More UNIX and Linux Forum Topics You Might Find Helpful
Thread	Thread Starter	Forum	Replies	Last Post
how to? launch command with string of command line options	TinCanFury	Shell Programming and Scripting	5	04-28-2008 06:06 PM
find command sort options?	mavsman	UNIX for Dummies Questions & Answers	6	04-01-2008 03:20 PM
Associated array from command line options	jperret	Shell Programming and Scripting	1	01-10-2008 05:16 PM
Split Command options	mohdtausifsh	UNIX for Advanced & Expert Users	7	10-04-2006 07:28 AM
Find command with prune and exec options	Sebarry	UNIX for Dummies Questions & Answers	2	06-19-2006 04:07 AM

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search
Display Modes	Rate This Thread
Switch to Linear Mode Hybrid Mode Switch to Threaded Mode	Rate This Thread: