[9fans] some shell scripts

[Russ Cox <russcox@gmail.com>]

First, a nice little clock for acme.
I "ported" this over to the Unix acme today
and realized I'd never posted it.  The ... around
the time is so that when you Sort it ends up at the top.

t23=; cat plan9/bin/rc/Clock
#!/bin/rc
cd /mnt/acme/new
while (date | sed 's/.* (..:..).*/name ...\1.../' >ctl)
	sleep 60

t23=; cat bin/Clock
#!/usr/local/plan9/bin/rc
n=`{9p read acme/new/ctl}
echo $n
n=$n(1)
while (date | 9sed 's/.* (..:..).*/name ...\1.../' | 9p write acme/$n/ctl)
	sleep 60
t23=; 

Second, inspired by reading about Nemo's tags,
I realized that, on Unix, I use locate | grep way too much
and I'm sick of typing really long path names.
This script L prints all names on the system 
matching the argument except that / can expand
to any number of elements.  So:

t23=; L plan9/acme
/usr/local/plan9/acid/acme
/usr/local/plan9/bin/acme
/usr/local/plan9/src/cmd/acme
t23=; L plan9/download.c
/usr/local/plan9/src/cmd/postscript/download/download.c
t23=; 

Plan 9 users will have to substitute locate with something
like du -a / in cron to update /tmp/locate-slash.

t23=; cat bin/L
#!/usr/local/plan9/bin/rc

TMP=/tmp

if(~ $#* 0){
	echo 'usage: L pth ...' >[1=2]
	exit usage
}

fn dogrep {
	if(~ $#* 1)
		grep /$1
	if not{
		x=$1
		shift
		grep /$x | dogrep $*
	}
}

# it is noticeably faster (.09s vs .55s) to just
# save the raw locate database somewhere [sic]
if(! test -f $TMP/locate-slash
|| test `{mtime $TMP/locate-slash | awk '{print $1}'} -lt `{hoc -e
`{$PLAN9/bin/date -n}^-86400})
	locate / >$TMP/locate-slash

nl='
'
for(i){
	ifs=$nl { pattern=`{echo $i | 9sed 's;\*;[^/]*;g; s;/;/(.*/)?;g;
s;^;(.*/)?;; s;$;$;'} }
	egrep $pattern $TMP/locate-slash
}
t23=;

and then the obvious next step is BL:

t23=; cat bin/BL
#!/usr/local/plan9/bin/rc

B `{L $*}
t23=;