On 03/19/2012 08:57 PM, Tiago Vignatti wrote: > + argv[argc] = argv[argc - 1] + strlen(argv[argc - 1]) +1; > + strcpy(argv[argc], "--help"); You want just: argv[argc] = "--help"; You do not need to copy any string anywhere, and certainly the above is not in any way guaranteed to give you some memory you can write to.