#!/usr/bin/env bash

# @(#) s1       Demonstrate extraction of fields, csvtool.

# 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 sed pass-fail
pe
dixf csvtool

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

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

pl " Input file converted to csv:"
sed -r 's/\s+/,/g' $FILE |
tee t1

pl " Header name file $H, name list:"
head $H
h1=$( paste -s -d, $H )
pe " Header list = $h1"

pl " Expected output:"
cat $E

pl " Results, extract columns, convert csv to TAB-spaced:"
csvtool namedcol $h1 t1 |
tee t2 |
sed -r 's/,/\t/g' |
tee f1

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

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 8.6 (jessie) 
bash GNU bash 4.3.30
dixf (local) 1.21
sed (GNU sed) 4.2.2
pass-fail (local) 1.9

csvtool tool for performing manipulations on CSV files from sh... (man)
Path    : /usr/bin/csvtool
Version : - ( /usr/bin/csvtool, 2014-08-06 )
Type    : ELF 64-bit LSB executable, x86-64, version 1 (SYSV ...)
Help    : probably available with --help
Home    : https://github.com/Chris00/ocaml-csv

-----
 Input data file data1:
H1 H2 H3 H4
01 02 03 04
11 12 13 14
21 22 23 24
31 32 33 34

-----
 Input file converted to csv:
H1,H2,H3,H4
01,02,03,04
11,12,13,14
21,22,23,24
31,32,33,34

-----
 Header name file headers, name list:
H3
H4
H1
H2
 Header list = H3,H4,H1,H2

-----
 Expected output:
H3      H4      H1      H2
03      04      01      02
13      14      11      12
23      24      21      22
33      34      31      32

-----
 Results, extract columns, convert csv to TAB-spaced:
H3      H4      H1      H2
03      04      01      02
13      14      11      12
23      24      21      22
33      34      31      32

-----
 Verify results if possible:

-----
 Comparison of 5 created lines with 5 lines of desired results:
 Succeeded -- files (computed) f1 and (standard) expected-output.txt have same content.