topic Re: filename pattern matching in Operating System - HP-UX

filename pattern matching

Mike Blansfield_1 — Sat, 02 Aug 2003 09:55:15 GMT

Hello,

I need to write a script that will do pattern matching of filenames. The pattern to be matched is the first 3 characters of the file and they must have this pattern:

A=alpha N=numeric
ANN AAN ANA

Any help appreciated!

Mike

Re: filename pattern matching

curt larson_1 — Sat, 02 Aug 2003 13:52:27 GMT

using dtksh you can do something like this

#!/usr/dt/bin/dtksh

while read filename
do
case $filename in
[:alpha:][:alnum:][:alnum:]*) print $filename;;
esac
done

of

if [[ "$filename" = [[:alpha:][:alnum:][:alnum:]]* ]] ;then
print $filename
fi

Re: filename pattern matching

James R. Ferguson — Sat, 02 Aug 2003 13:52:31 GMT

Hi Mike:

I'll use regular expressions with 'awk' and 'ls' to generate the input:

# ls -l|awk '$NF~/^[[:alpha:]][0-9]][0-9]/ || $NF~/^[[:alpha:]][[:alpha:]][0-9]/ || $NF~/^[[:alpha:]][0-9]][[:alpha:]]/ {print $NF}'

This takes the output from 'ls' and examines the filename (the last field of each line) and prints it if it meets the criteria you specified for the first three characters. The '||' is an 'or' operator.

Regards!

...JRF...

Re: filename pattern matching

curt larson_1 — Sat, 02 Aug 2003 13:56:40 GMT

or using sed

ls |
sed -n '/^[:alpha:][:alpha:,0-9]\{2\}/p'

Re: filename pattern matching

Chris Vail — Mon, 04 Aug 2003 18:07:25 GMT

ls -l [a-z] [0-9] [0-9] *| [a-z] [a-z] [0-9]*| [a-z] [0-9] [a-z] *

I haven't tested it, but this should work.

Re: filename pattern matching

john korterman — Tue, 05 Aug 2003 10:35:48 GMT

Hi,
I have tested this and it seems to work:
(should be on a single line with no spaces between ??? and ???):

# ls | egrep "^[[:alpha:]][[:digit:]][[:digit:]]|^[[:alpha:]][[:alpha:]][[:digit:]]|^[[:alpha:]][[:digit:]][[:alpha:]]"

It has the obvious advantage of being easy to read!
The output from ls is redirected to egrep, which tries to match the extended reg. expression described between ??? and ???
The expression itself holds three alternatives, separated from one another by a pipe character.
Each alternative starts with the hat/caret character, which means ???must start with this???.
The allowed character combination for each alternative is described by so-called character-classes, e.g. [:alpha:] meaning any alphabetical character. A class is always surrounded by colons and a set of square brackets.
What you put in between square brackets, in this case the ???outer??? square brackets, means ???match any single one of the character(s) mentioned.
Hence, match any one alphabethical character appearing at the beginning looks like this: ^[[:alpha:]]

regards,
John K