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From: lwall@jato.Jpl.Nasa.Gov (Larry Wall)
Newsgroups: alt.sources,comp.lang.perl
Subject: Re: Version of id(1).
Message-ID: <2969@jato.Jpl.Nasa.Gov>
Date: 2 Mar 90 22:50:23 GMT
References: <426@clover.warwick.ac.uk> <2964@jato.Jpl.Nasa.Gov> <1990Mar2.210209.11209@iwarp.intel.com>
Reply-To: lwall@jato.Jpl.Nasa.Gov (Larry Wall)
Organization: Jet Propulsion Laboratory, Pasadena, CA
Lines: 33

In article <1990Mar2.210209.11209@iwarp.intel.com> merlyn@iwarp.intel.com (Randal Schwartz) writes:
: In article <2964@jato.Jpl.Nasa.Gov>, lwall@jato (Larry Wall) writes:
: [21 lines of code deleted...]
: | No doubt Randal could write it shorter...
: 
: Well, OK, taking on the challenge, how about:
: 
: #!/usr/bin/perl
: sub u { local($name)=getpwuid($_[0]); $name && "($name)";}
: sub g { local($name)=getgrgid($_[0]); $name && "($name)";}
: sub bynum { $a - $b; }
: print "uid=$<",&u($<);
: print " gid=", $(+0,&g($();
: print " euid=$>",&u($>) if $> != $<;
: print " egid=", $)+0,&g($)) if $) != $(;
: @groups=split(' ',$(); shift(@groups);
: print " groups=", join(',',sort bynum grep(($_ .= &g($_)) || 1, @groups))
: 	unless $#groups < $[;
: print "\n";
: 
: Something like that, Larry?

That's not short.  This is short:         :-)

#!/usr/bin/perl
@n=('pwu','grg');sub n{local($n)=eval"get$n[$_[1]]id(\$_[0])";$n&&"($n)";}sub nm
{$a-$b;}@gr=split(' ',$();$g=shift(@gr);$\="\n";print"uid=$<",&n($<)," gid=",$g,
&n($(,1),(" euid=$>".&n($>))x($<!=$>),(" egid=".$)+0 .&n($),1))x($(!=$)),
(" groups=".join(',',sort nm grep(($_.=&n($_,1))||1,@gr)))x($#gr>=0);

Though I'll admit readability suffers slightly...

Larry