processing arguments

processing arguments

[ameer armaly]

Hi all.
Let's say that I have the following c++ code:
#include <iostream>
int main(int argc, char *argv[])
{
if(argv[1]=="hello")
cout <<"Hello World!";
return 0;
}


When I try that, and I type:
./a.out hello

It doesn't give me any output.
Can someone explain how to process args properly?
Thanks,


Ameer

Re: processing arguments

[Chuck Winters]

Ameer,
  Your if stmt:
    if(argv[1] == "hello")
  is only comparing the pointer values in memory.  You need
  to use strncmp(3) to do comparison on strings.

Chuck

On Fri, 2004-04-23 at 16:44, ameer armaly wrote:
     Hi all.
     Let's say that I have the following c++ code:
     #include <iostream>
     int main(int argc, char *argv[])
     {
     if(argv[1]=="hello")
     cout <<"Hello World!";
     return 0;
     }


     When I try that, and I type:
     ./a.out hello

     It doesn't give me any output.
     Can someone explain how to process args properly?
     Thanks,


     Ameer

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Re: processing arguments

[A. Murat Eren]

 Hi,

> if(argv[1]=="hello")

 man strcmp

 you can not compare strings like yours..


 regards, murat.
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Re: processing arguments

[vadiraj]

Hi,

> When I try that, and I type:
> ./a.out hello
>
> It doesn't give me any output.
> Can someone explain how to process args properly?
> Thanks,

  args are no special data type, they are just two dimenstional char array,
all the strings functions apply to them. Like the others mentioned
string compare should be done either charecter by charecter or use the
lib function on strings.


cheers,
Vadi.