Shell Programming and Scripting

awk '
function rbefore(STR)   { return(substr(STR, 0, RSTART-1)); }# before match
function rall(STR)      { return(substr(STR, RSTART, RLENGTH)); }# Entire match
function rafter(STR)    { return(substr(STR, RSTART+RLENGTH)); }# after

# First line:  Reformat headers for sorting and find new order
NR==1 {
    for(N=1; N<=NF; N++)
    {
        IN=$N
        OUT=""

        # Convert a_3 to a_00000003 so it will sort
        while(match(IN, /[0-9]+/))
        {
                OUT=OUT rbefore(IN) sprintf("%08d", rall(IN));
                IN=rafter(IN);
        }

        OUT=OUT IN;
        A[OUT]=N # Creating an array of A["string_0001"]=N
    }

    C=asorti(A, B); # Sort it into B[1]="string_0001", B[2]="string_0003" etc
    for(X in B) D[X]=A[B[X]]; # D[1]=4, maps in to out column
}

# All lines: Assemble string from column order and print
{
        OUT=""
        for(N=1; N<=C; N++) OUT=OUT OFS $(D[N])
        print substr(OUT,2);
}

' FS=";" OFS=";" inputfile > outputfile

read LINE < file
echo $LINE | tr '_;' ' '$'\n' | sort -k2n | tr ' ' '_' | awk -F";" '
FNR == NR       {T[$0] = NR
                 MX = NR
                 next
                }
FNR == 1        {for (i=1; i<=NF; i++)  S[T[$i]] = i
                }
                {for (i=1; i<=MX; i++)  printf "%s%s", $(S[i]), (i==MX)?ORS:FS
                }
' - file

line < file2 | tr ';' $'\n' | sort -t_ -k2n | awk ...

$ 
$ cat input_1.txt
1_ICD;11_ICD;15_ICD;3_ICD
a1;a11;a15;a3
$ 
$ 
$ perl -F';' -lane 'if ($. == 1){
                        %x = map{ $F[$_] => $_ } (0..$#F);
                        @s = map{ $x{$_} } sort { (split "_", $a)[0] <=> (split "_", $b)[0] } @F;
                    }
                    print join ";", map{ $F[$s[$_]] }(0..$#F);
                   ' input_1.txt
1_ICD;3_ICD;11_ICD;15_ICD
a1;a3;a11;a15
$ 
$

$ 
$ cat input_2.txt
1_ICD;ICD_11;15_ICD;ICD_3
a1;a11;a15;a3
$ 
$

$ 
$ perl -F';' -lane 'if ($. == 1){
                        %x = map{ $F[$_] => $_ } (0..$#F);
                        %y = map{ $m = $_; ($n = $m) =~ s/\D//g; $m => $n } @F;
                        @s = map{ $x{$_} } sort { $y{$a} <=> $y{$b} } keys(%y);
                    }
                    print join ";", map{ $F[$s[$_]] }(0..$#F);
                   ' input_2.txt
1_ICD;ICD_3;ICD_11;15_ICD
a1;a3;a11;a15
$ 
$

1_ICD;2_ICD_6;5_ICD;ICD_7
aa;bb;cc;dd

#!/usr/bin/env bash

# @(#) s1       Demonstrate sort headers, carrying data fields, datamash, msort

# Utility functions: print-as-echo, print-line-with-visual-space, debug.
# export PATH="/usr/local/bin:/usr/bin:/bin"
LC_ALL=C ; LANG=C ; export LC_ALL LANG
pe() { for _i;do printf "%s" "$_i";done; printf "\n"; }
pl() { pe;pe "-----" ;pe "$*"; }
em() { pe "$*" >&2 ; }
db() { ( printf " db, ";for _i;do printf "%s" "$_i";done;printf "\n" ) >&2 ; }
db() { : ; }
C=$HOME/bin/context && [ -f $C ] && $C dixf datamash msort

FILE=${1-data1}
E=expected-output.txt

pl " Input data file $FILE:"
head $FILE

pl " Expected output:"
head $E

# See f3 and f2 for intermediate output.
pl " Results:"
datamash -t ';' transpose < $FILE |
tee f3 |
msort -q -l -n 1,1 -d ';' --comparison-type hybrid |
tee f2 |
datamash -t ';' transpose |
tee f1

pl " Verify results if possible:"
C=$HOME/bin/pass-fail
[ -f $C ] && $C || ( pe; pe " Results cannot be verified." ) >&2

pl " Some detail for datamash, msort:"
dixf datamash msort

exit 0

$ ./s1

Environment: LC_ALL = C, LANG = C
(Versions displayed with local utility "version")
OS, ker|rel, machine: Linux, 3.16.0-4-amd64, x86_64
Distribution        : Debian 8.8 (jessie) 
bash GNU bash 4.3.30
dixf (local) 1.50
datamash (GNU datamash) 1.0.6
msort 8.53

-----
 Input data file data1:
a_13;a_2;a_1;a_10
13;2;1;10

-----
 Expected output:
a_1;a_2;a_10;a_13
1;2;10;13

-----
 Results:
a_1;a_2;a_10;a_13
1;2;10;13

-----
 Verify results if possible:

-----
 Comparison of 2 created lines with 2 lines of desired results:
 Succeeded -- files (computed) f1 and (standard) expected-output.txt have same content.

-----
 Some detail for datamash, msort:

datamash        command-line calculations (man)
Path    : /usr/bin/datamash
Version : 1.0.6
Type    : ELF 64-bit LSB executable, x86-64, version 1 (SYSV ...)
Help    : probably available with -h,--help
Repo    : Debian 8.8 (jessie) 
Home    : https://savannah.gnu.org/projects/datamash/ (pm)

msort   sort records in complex ways (man)
Path    : /usr/bin/msort
Version : 8.53
Type    : ELF 64-bit LSB executable, x86-64, version 1 (SYSV ...)
Repo    : Debian 8.8 (jessie) 
Home    : http://www.billposer.org/Software/msort.html (pm)

tr ';' '\n'