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From: lothar@tmcsys.UUCP (L. Hirschbiegel)
Newsgroups: comp.unix.sysv386,comp.lang.c
Subject: Re: time(0L) - history of a misconception (was Re: SCO password generator)
Message-ID: <381@tmcsys.UUCP>
Date: 21 May 91 22:27:59 GMT
References: <1991May14.040042.15199@jpradley.jpr.com> <588@sherpa.UUCP> <1141@mwtech.UUCP>
Reply-To: lh@aega84.UUCP (L. Hirschbiegel)
Organization: Private Site
Lines: 72

In article <1141@mwtech.UUCP> martin@mwtech.UUCP (Martin Weitzel) writes:
>In article <588@sherpa.UUCP> rac@sherpa.UUCP (Roger Cornelius) writes:
>[...]
>>	long seed = time(0L);
>	                 ^^--------- wrong
>	           time((long *)0);
>	                ^^^^^^^^^--- right
>

You're a cousin of "lint", aren't you :-) ?

>Note that the argument to the time system call is a `long *', aka
>pointer to long. 

Ever tried to RTFM for yourself? 

	  NAME
	       time - get time

	  DESCRIPTION
	       The time	system call returns the	value of time in seconds
	       since 00:00:00 Greenwich	Mean Time (GMT), January 1, 1970.

	       If tloc is non-zero, the	return value is	also stored in the
                   ^^^^^^^^^^^
	       location	to which tloc points.

If you still don't understand: I'll help you! 
For this little test program:

main()
{
time(0L);
time((long *)0);
}

the assembler output from my C compiler is:

	.file	"main.c"
gcc_compiled.:
.text
	.align 4
.globl main
main:
	pushl %ebp
	movl %esp,%ebp
	pushl $0
	call time
	pushl $0
	call time
.L1:
	leave
	ret

>Repeat after me: POINTER to long.

Repeat after me: IT DOESN'T MATTER :-)

>I'm always wondering why people can't grasp
>the difference between a plain integer, a long and pointers to any of it.

So do I...

>-- 
>Martin Weitzel, email: martin@mwtech.UUCP, voice: 49-(0)6151-6 56 83

Lothar Hirschbiegel
-- 
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L. Hirschbiegel, AEG - A84, Frankfurt (Germany) 
email: unido!aega84!lh     tel: -49-69-66414316  
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