wyle@solaris.UUCP (Mitchell Wyle) (07/26/88)
Is there a better way to parse numeric ranges than the following?
------------------------- snip here -------------------------
#!/bin/sh
#
# parse a range of numbers in the form:
#
# <range> :== <number>
# | <number>,range
# | <number>-<number>
# | <number>-
#
# <number>:== <digit><number>
#
# <digit> :== 0|1|2|3|4|5|6|7|8|9
#
# ...to create a list of numbers; e.g. 1,3,8-11 -> 1 3 8 9 10 11
#
# input range is in variable $RA ($1 for this example)
RA=$1
echo in: $RA
R=""
RA=`echo $RA | sed 's/,/\ /g'`
for tok in $RA ; do
if echo $tok | grep -s '\-' ; then
t=`echo $tok | sed 's/-/ - /'`
set $t
i=$1
max=${3:-99}
while test $i -le $max ; do
R=$R" "$i
i=`expr $i + 1`
done
else
R=$R" "$tok
fi
RA=$R
done
echo out: $RA
------------------------- snip here -------------------------
Is there a faster way? How does Larry Wall's mailpatch work?
Curious minds want to know!
--
-Mitchell F. Wyle wyle@ethz.uucp
Institut fuer Informatik wyle%ifi.ethz.ch@relay.cs.net
ETH Zentrum
8092 Zuerich, Switzerland +41 1 256-5237lwall@jpl-devvax.JPL.NASA.GOV (Larry Wall) (08/19/88)
In article <469@solaris.UUCP> wyle@solaris.UUCP (Mitchell Wyle) writes:
: Is there a better way to parse numeric ranges than the following?
[sh script to do ranges omitted]
: Is there a faster way? How does Larry Wall's mailpatch work?
:
: Curious minds want to know!
The mailpatch script calls a C program to do the ranges. The patch sender
built into the dist package is written in perl, which groks numbers a bit
better than sh does. One of these days I'll rewrite mailpatch in perl and
delete the C program.
Larry Wall
lwall@jpl-devvax.jpl.nasa.gov