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Path: utzoo!utgpu!water!watmath!clyde!cbosgd!ihnp4!chinet!rlk
From: rlk@chinet.UUCP
Newsgroups: comp.lang.c
Subject: Re: A better perror() (Was: Re: Accessing argc ...)
Message-ID: <1427@chinet.UUCP>
Date: Thu, 20-Aug-87 23:19:12 EDT
Article-I.D.: chinet.1427
Posted: Thu Aug 20 23:19:12 1987
Date-Received: Sat, 22-Aug-87 18:09:47 EDT
References: <22@flmis06.ATT.COM> <28700015@ccvaxa> <853@mcgill-vision.UUCP> <1351@killer.UUCP>
Reply-To: rlk@chinet.UUCP (Richard Klappal)
Organization: Chinet - Public Access Unix
Lines: 39

In article <1351@killer.UUCP> molly@killer.UUCP (Molly Fredericks) writes:
>In article <853@mcgill-vision.UUCP>, mouse@mcgill-vision.UUCP (der Mouse) writes:
>> In article <28700015@ccvaxa>, aglew@ccvaxa.UUCP quotes:
>> > I have always thought that perror(str) was silly - sometimes I want
>> > str to be the command name, sometimes the command plus all
>> > arguments...
>> 
>> [ ... ] Wish perror() were printflike, perhaps like
>> syslog() - syslog() accepts a printf format, except that %m means
>> insert sys_errlst[errno].
>
>I have seen a few public domain printf's come down the line (the most
...

My solution to this is

	extern int	errno;
	extern char	*sys_errlist[];

	#define	SYS_ERRMSG	sys_errlist[errno]

	.
	.
	printf("..whatever..: %s\n", args_for_whatever, SYS_ERRMSG);

This method assumes that 'errno' has been correctly supplied a value.
(e.i., That an error occured.)

Do an 'nm' command on libc.a to confirm the existence of these names,
if not using a standard UN*X (works on SYSV, and on my BSD-derived
system.)



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