Re: integer and long max/min values
On Fri, 21 Nov 2003, Duane H. Hesser wrote: On 21-Nov-2003 Richard Coleman wrote: Jay Sern Liew wrote: how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) if it's compiler-dependent, then does anyone know where I can find the GCC documentation for stuff like that? It will be architecture dependent (32 or 64 bit machines?). I doubt the GCC docs talk about this. You might check Richard Steven's book on Advanced Unix Programming. It covers lots of information about standard machine limits and how to discover them. As a point of interest, there is a file /usr/src/contrib/gcc/enquire.c in the distributed sources which, when compiled and run, will report the max and min values of short, long, int, float, etc. along with various sizes and alignments. To get the latest version (5.1a) of enquire: http://homepages.cwi.nl/~steven/enquire.html Sean --- [EMAIL PROTECTED] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: integer and long max/min values
Jay Sern Liew wrote: how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) #include limits.h INT_MAX and INT_MIN are the max/min values for an int LONG_MAX and LONG_MIN are the max/min values for long. Also, see stdint.h, which is defined in C99. Also, buy a good C reference book. ;-) Tim Kientzle ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: integer and long max/min values
Jay Sern Liew wrote: how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) if it's compiler-dependent, then does anyone know where I can find the GCC documentation for stuff like that? It will be architecture dependent (32 or 64 bit machines?). I doubt the GCC docs talk about this. You might check Richard Steven's book on Advanced Unix Programming. It covers lots of information about standard machine limits and how to discover them. Richard Coleman [EMAIL PROTECTED] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
RE: integer and long max/min values
Write a simple C program to ++ an int or long variable and see when it overflows. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of ext Tim Kientzle Sent: Friday, November 21, 2003 12:24 AM To: Jay Sern Liew Cc: [EMAIL PROTECTED] Subject: Re: integer and long max/min values Jay Sern Liew wrote: how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) #include limits.h INT_MAX and INT_MIN are the max/min values for an int LONG_MAX and LONG_MIN are the max/min values for long. Also, see stdint.h, which is defined in C99. Also, buy a good C reference book. ;-) Tim Kientzle ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: integer and long max/min values
On Fri, Nov 21, 2003 at 09:53:50AM -0800, [EMAIL PROTECTED] wrote: [format recovered; Tim Kientzle wrote:] Jay Sern Liew wrote: how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) #include limits.h INT_MAX and INT_MIN are the max/min values for an int LONG_MAX and LONG_MIN are the max/min values for long. Also, see stdint.h, which is defined in C99. Also, buy a good C reference book. ;-) Tim Kientzle [..and Vijay Singh wrote:] Write a simple C program to ++ an int or long variable and see when it overflows. Why, after Tim actually quoted the exact header file to include and the exact constants to use? G'luck, Peter -- Peter Pentchev [EMAIL PROTECTED][EMAIL PROTECTED][EMAIL PROTECTED] PGP key:http://people.FreeBSD.org/~roam/roam.key.asc Key fingerprint FDBA FD79 C26F 3C51 C95E DF9E ED18 B68D 1619 4553 You have, of course, just begun reading the sentence that you have just finished reading. pgp0.pgp Description: PGP signature
Re: integer and long max/min values
'Tis a bit of a waste of cpu time there. On a two's complement system, which is probably all you'll come by, you can find UINT_MAX by setting an unsigned integer to -1: unsigned int i_max = -1; A slightly more architecturally independent way of finding UINT_MAX would be to set an unsigned integer to the complement of its zero: unsigned int i_max = ~(unsigned int)0; Either way, you can find the positive signed maximum by dividing your result by two (discarding the remainder). Try the following: #include limits.h #include assert.h ... assert ((unsigned int)-1 == UINT_MAX); assert (~(unsigned int)0 == UINT_MAX); assert (((unsigned int)-1)/2 == INT_MAX); assert ((~(unsigned int)0)/2 == INT_MAX); ... Some may argue against this method, but using an unsigned complement of zero should hold at least the portability of assuming NULL to be false. The *_MAX macros, of course, should still be used whenever possible. ari [EMAIL PROTECTED] said this stuff: Write a simple C program to ++ an int or long variable and see when it overflows. -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] Behalf Of ext Tim Kientzle Sent: Friday, November 21, 2003 12:24 AM To: Jay Sern Liew Cc: [EMAIL PROTECTED] Subject: Re: integer and long max/min values Jay Sern Liew wrote: how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) #include limits.h INT_MAX and INT_MIN are the max/min values for an int LONG_MAX and LONG_MIN are the max/min values for long. Also, see stdint.h, which is defined in C99. Also, buy a good C reference book. ;-) Tim Kientzle ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: integer and long max/min values
On 21-Nov-2003 Richard Coleman wrote: Jay Sern Liew wrote: how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) if it's compiler-dependent, then does anyone know where I can find the GCC documentation for stuff like that? It will be architecture dependent (32 or 64 bit machines?). I doubt the GCC docs talk about this. You might check Richard Steven's book on Advanced Unix Programming. It covers lots of information about standard machine limits and how to discover them. Richard Coleman [EMAIL PROTECTED] As a point of interest, there is a file /usr/src/contrib/gcc/enquire.c in the distributed sources which, when compiled and run, will report the max and min values of short, long, int, float, etc. along with various sizes and alignments. -- -- Just be glad Microsoft doesn't make passenger airplanes. Duane H. Hesser [EMAIL PROTECTED] -- ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
integer and long max/min values
how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) if it's compiler-dependent, then does anyone know where I can find the GCC documentation for stuff like that? thanks. Jay Sern Liew [EMAIL PROTECTED],ieee}.org gpg --keyserver pgp.mit.edu --recv-keys 0xA115A33F pub 1024D/A115A33F 2003-01-02 Jay Sern Liew [EMAIL PROTECTED] Key fingerprint = B08E 2481 B4CE 284A C0DE E359 8646 7B7E A115 A33F sub 1024g/7504C197 2003-01-02 [expires: 2003-12-31] ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: integer and long max/min values
On Thu, Nov 20, 2003 at 10:39:05PM -0600, Jay Sern Liew wrote: how do I find out the maximum (and minimum) value a long and int will hold in C? (before it overflows or underflows) if it's compiler-dependent, then does anyone know where I can find the GCC documentation for stuff like that? Wrong mailing list - if you don't already know really basic C, you ain't a hacker. Try limits.h. -- Christopher Vance ___ [EMAIL PROTECTED] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to [EMAIL PROTECTED]
