crashme(1) [debian man page]

CRASHME(1)						      General Commands Manual							CRASHME(1)

NAME

       crashme - test operating environment software robustness

SYNOPSIS

       crashme [NBYTES] [SRAND] [NTRYS] [NSUB] [VERBOSE]

DESCRIPTION

       crashme	is a very simple program that tests the operating environment's robustness by invoking random data as if it were a procedure.  The
       standard signals are caught and handled with a setjmp back to a loop which will try again to produce a fault by executing random data. Some
       people call this stress testing.

   COMMAND LINE OPTIONS
       [NBYTES]
	       The  [NBYTES]  should  be  an integer, specifying the size of the random data string in bytes. If given negative then the bytes are
	       printed instead of being executed. If given with an explicit plus sign then the storage for the bytes  is  freshly  malloc'ed  each
	       time.  This  can have an effect on machines with seperate I and D cache mechanisms. The argument can also have a dot in it, X.Y, in
	       which case Y is a increment for a pointer into the random data. The buffer is recalculated only when the pointer gets near the  end
	       of the data.

       [SRAND] The [SRAND] is an input seed to the random number generator, passed to srand.

       [NTRIES]
	       The [NTRIES] is how many times to loop before exiting normally from the program.

       [NSUB]  The  [NSUB]  is	optional,  the number of vfork subprocesses running all at once.  If negative run one after another. If given as a
	       time hrs:mns:scs (hours, minutes, seconds) then one subprocess will be run to completion, followed by another, until the time limit
	       has been reached.  If this argument is given as the empty string or . then it is ignored.

	       When  in  sequential-subprocess mode there is a 30 second time limit on each subprocess. This is to allow the instruction-set-space
	       random walk to continue when a process bashes itself into an infinite loop.  For example, the ntrys can be bashed to a  very  large
	       number with nbytes bashed to zero. (10 second limit on Windows NT).

	       The SRAND argument is incremented by one for each subprocess.

       [VERBOSE]
	       The [VERBOSE] arg is optional. 0 is the least verbose, 5 the most.

EXAMPLE

       This is a suggested test, to run it for a least an hour.

       crashme +2000 666 100 1:00:00

FILES

       crashme.c

DIAGNOSTICS

       When  a	signal is caught the number and nature of the signal is indicated.  Setting the environment variable CRASHLOG will cause each sub-
       process to record the arguments it was given.

BUGS

       Not all signals are caught, and the state of the user program/process enviroment can be sufficiently damaged such that the  program  termi-
       nates before going through all [NTRIES] operations.

       If  the architecture uses some kind of procedure descriptor but no special code has been not been added to castaway() in crashme.c then the
       stress test will not be as potent as it would otherwise be.

       Beware: This program can crash your computer if the operating system or hardware of same is buggy. User data may be lost.

AUTHOR

       George J Carrette. GJC@world.std.com

VERSION

       2.4 20-MAY-1994

								       LOCAL								CRASHME(1)

Check Out this Related Man Page

RANDOM(3)						     Linux Programmer's Manual							 RANDOM(3)

NAME

       random, srandom, initstate, setstate - random number generator.

SYNOPSIS

       #include <stdlib.h>

       long int random(void);
       void srandom(unsigned int seed);
       char *initstate(unsigned int seed, char *state, size_t n);
       char *setstate(char *state);

DESCRIPTION

       The  random()  function	uses  a non-linear additive feedback random number generator employing a default table of size 31 long integers to
       return successive pseudo-random numbers in the range from 0 to RAND_MAX.  The period of this random number generator is very large, approx-
       imately 16*((2**31)-1).

       The  srandom()  function  sets  its  argument  as  the seed for a new sequence of pseudo-random integers to be returned by random().  These
       sequences are repeatable by calling srandom() with the same seed value.	If no seed value is provided, the random() function  is  automati-
       cally seeded with a value of 1.

       The  initstate() function allows a state array state to be initialized for use by random().  The size of the state array n is used by init-
       state() to decide how sophisticated a random number generator it should use -- the larger the state array, the better  the  random  numbers
       will  be.   seed  is  the  seed	for  the initialization, which specifies a starting point for the random number sequence, and provides for
       restarting at the same point.

       The setstate() function changes the state array used by the random() function.  The state array state is used for random number	generation
       until  the next call to initstate() or setstate().  state must first have been initialized using initstate() or be the result of a previous
       call of setstate().

RETURN VALUE

       The random() function returns a value between 0 and RAND_MAX.  The srandom() function returns no value.	 The  initstate()  and	setstate()
       functions return a pointer to the previous state array, or NULL on error.

ERRORS

       EINVAL A state array of less than 8 bytes was specified to initstate().

NOTES

       Current	"optimal"  values  for	the size of the state array n are 8, 32, 64, 128, and 256 bytes; other amounts will be rounded down to the
       nearest known amount.  Using less than 8 bytes will cause an error.

CONFORMING TO

       BSD 4.3

SEE ALSO

       rand(3), srand(3)

GNU
								    2000-08-20								 RANDOM(3)

Linux and UNIX Man Pages

crashme(1) [debian man page]

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