mkid from id-utils segvs on GNU/Linux

[Sam Roberts]

The problem is this snippet of code:

char* dot = (char*) ".";

The compiler warns about this, the cast removes the warning, and
the string is passed to strtok(), which segvs when attempting to write
it.

On GNU/Linux, gcc puts string literals in read-only data.

Something like this is necessary:

char dot[] = ".";
char* dotp= dot;
argv = &dotp;

Sam