How to call command macro from C function

[Bargi]

Hi ,

I want to call a command macro from a function.

I am using system() function in linux.
The problem is that,when I add parameters to it, I am using strcat() function, but it is giving me segmentation fault.

The code is as follow:

int main()
{
  char *s="ls";
  strcat(s,"-l");
  system(s);	
}

Thanks
Bargi

[matsp]

Yes, you can not append to a string literal (string constant). You could declare a char array that is initialized, if you want to do that sort of thing. And you will need to put a space between ls and -l too!

--
Mats

[vart]

s is pointer to read only memory
you cannot write there

use buffer big enough to store the original string + all additions instead

[Bladactania]

Why don't you just do

int main {
  char *s = "ls -l";
  system(s);
}

[Bargi]

yes ,I can do that......
but string can increase later...