If I use ls to print all the files of a folder, is there a way to sort using roman numerals?
I am thinking about a result like:
benjamin_I.wmv
benjamin_II.wmv
benjamin_II.wmv
benjamin_III.wmv
benjamin_IV.wmv
benjamin_V.wmv
benjamin_VI.wmv
benjamin_VII.wmv
benjamin_VIII.wmv
benjamin_IX.wmv
The roman numerals are always preceded by an underscore.
Your best bet is probably perl's 'Roman' module.
Download Roman.pm from CPAN here: http://search.cpan.org/~chorny/Roman-1.23/lib/Roman.pm
copy it into /usr/lib/perl5/site_perl/5.8.8/ (adjust to your perl version).
Create a perl script sortRoman.pl:
#!/usr/bin/perl -w
use Roman;
sub romanSort { #custom sorting definition
$a =~ /^.*_([MDCLXVI]+)\..*/; #capture all roman numerals after underscore
$aRom = arabic($1); #convert captured roman number to arabic (e.g. XIV --> 14 )
$b =~ /^.*_([MDCLXVI]+)\..*/; #repeat with second input
$aRom <=> arabic($1); #numeric comparison between the converted numbers
}
@data = (<>); #slurp the whole input into one array
print sort romanSort @data; #print sorted array using custom routine romanSort
make it executable
chmod 754 sortRoman.pl
and try it out:
$ cat testdata
b_II.wmv
b_III.wmv
b_IX.wmv
b_IV.wmv
b_VI.wmv
b_V.wmv
b_VII.wmv
b_CXLIV.wmv
b_CXIV.wmv
b_CXII.wmv
A_B_XIV.wmv
$ ./sortRoman.pl testdata
b_II.wmv
b_III.wmv
b_IV.wmv
b_V.wmv
b_VI.wmv
b_VII.wmv
b_IX.wmv
A_B_XIV.wmv
b_CXII.wmv
b_CXIV.wmv
b_CXLIV.wmv
Egads... I'd translate the numbers from roman numerals into normal numbers, sort, then change them back.
# roman.awk
# Adapted from a clever converter found here
# http://scripts.mit.edu/~yfarjoun/homepage/index.php?title=Code_Snippets
BEGIN {
R["I"]=1; R["V"]=5; R["X"]=10; R["L"]=50;
R["C"]=100; R["D"]=500; R["M"]=1000;
E["iv"]="IIII"; E["ix"]="VIIII";
E["xl"]="XXXX"; E["xc"]="LXXXX";
E["cd"]="CCCC"; E["cm"]="DCCCC";
E["iix"]="VIII"; E["xxc"]="LXXX";
E["ccm"]="DCCC"; E["vl"]="XXXXV";
E["ld"]="CCCCL";
}
function roman_arabic(RN)
{
SUM=0;
RN=tolower(RN);
# Substitute roman numeral forms into things we can count.
# Substitue lower case for upper case so substitutions
# don't happen twice by accident.
for(K in E) while(sub(K, E[K], RN));
# Convert anything that didn't get substituted to uppercase.
RN=toupper(RN);
for(K in R) while(sub(K, "", RN)) SUM+=R[K];
return(SUM);
}
{
split($0, ARR, /[_.]/);
if($0 ~ /_[iIvVlLxXcCdDmM]+/)
{
# print ARR[1], ARR[2], ARR[3];
printf("%s<!--%d-->_%s.%s\n", ARR[1], roman_arabic(ARR[2]), ARR[2], ARR[3]);
}
}
$ awk -f roman.awk < list
benjamin<!--1-->_I.wmv
benjamin<!--8-->_VIII.wmv
benjamin<!--4-->_IV.wmv
benjamin<!--5-->_V.wmv
benjamin<!--2-->_II.wmv
benjamin<!--2-->_II.wmv
benjamin<!--9-->_IX.wmv
benjamin<!--7-->_VII.wmv
benjamin<!--3-->_III.wmv
benjamin<!--6-->_VI.wmv
$ awk -f roman.awk < list | sort
benjamin<!--1-->_I.wmv
benjamin<!--2-->_II.wmv
benjamin<!--2-->_II.wmv
benjamin<!--3-->_III.wmv
benjamin<!--4-->_IV.wmv
benjamin<!--5-->_V.wmv
benjamin<!--6-->_VI.wmv
benjamin<!--7-->_VII.wmv
benjamin<!--8-->_VIII.wmv
benjamin<!--9-->_IX.wmv
$ awk -f roman.awk < list2 | sort | sed -r 's#<!--.*-->##g'
benjamin_I.wmv
benjamin_II.wmv
benjamin_II.wmv
benjamin_III.wmv
benjamin_IV.wmv
benjamin_V.wmv
benjamin_VI.wmv
benjamin_VII.wmv
benjamin_VIII.wmv
benjamin_IX.wmv
$
...but beware of all the valid words that can be made from roman numerals:
$ egrep -i "^[IVXLCRDM]{3}[IVXLCRDM]*$" /usr/share/dict/cracklib-small
cdc
cdr
civic
civil
did
dill
dim
drill
icc
iii
ill
lid
lim
livid
mid
mild
mill
mimi
mimic
mix
rid
rill
rim
vii
viii
vivid
$
What does this arabic($1) stand for ????
@centurion_13: arabic() is a function defined in Roman.pm module, to convert roman number to arabic (e.g.
$a = "XLVII";
$b = arabic($a); # b==47
That's what that Roman.pm module is made for.
$1 references what was captured in a most recent regex with parentheses.
I added comments to my original reply.
Hi.
The utility msort is in the Debian GNU/Linux repositories. It often makes life easy for complex sorting situations:
#!/usr/bin/env bash
# @(#) s2 Demonstrate sort of roman numerals, msort.
# http://freshmeat.net/projects/msort
# Utility functions: print-as-echo, print-line-with-visual-space, debug.
pe() { for i;do printf "%s" "$i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
db() { ( printf " db, ";for i;do printf "%s" "$i";done; printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && . $C ;msort
msort --version | head -1
FILE=${1-data3}
pl " Data file $FILE:"
cat $FILE
pl " Results, msort on roman numerals, field 2:"
msort --quiet --line --position 2 --comparison-type numeric --number-system roman $FILE
exit 0
producing:
% ./s2
Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version"ker|rel
er|rel, machine: Linux, 2.6.32-5-686, i686
Distribution : Debian GNU/Linux 6.0
GNU bash 4.1.5
msort 8.53
-----
Data file data3:
file ii suffix
file i suffix
file iv suffix
file iii suffix
file c suffix
-----
Results, msort on roman numerals, field 2:
file i suffix
file ii suffix
file iii suffix
file iv suffix
file c suffix
If you do not use Debian, see the msort home page as noted in the script.
Best wishes ... cheers, drl
PS. I had trouble with older versions of msort on 64-bit Debian (lenny), but the version of msort on the current stable edition (squeeze) seems to work correctly, as noted above.
...and in case it's unclear, "arabic" numerals are normal numbers, digits 0 through 9 etc.