system() --- the C function from hell?

[David McIntyre]

In article <1827 at uop.edu> jeff at uop.edu (Jeff Ferguson) writes:
>	The system() call seems to wreak havoc with integer variables.
>I have the following code:
>
>int lowp, hip;
>...
>scanf("%d", &hip);
>scanf("%d", &lowp);
>sprintf(str, "/bin/mkdir directory");
>system(str);
>...
>
>I printed the values of LOWP and HIP before the system() call, and
>everthing was pee-chee (like the folder).  I print them out after
>the call and the values have been blown to high Heaven: before they
>were both 3, while after system(str) they are in the tens of millions.

I would suggest that str is a (char *) variable that has not
had any space allocated for it, and it is overwriting the
two integers somehow.  You should either make str something like

char str[20];

or malloc it, something like this:

	str = (char *)malloc(20*sizeof(char));


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