mjhjmtu

I have a file delimited with space and random column ordering as follows:

name=Joan age=42 ip=172.20.1.80 sex=M loc=UK 
loc=IR sex=F ip=172.20.1.1 age=32 name=Sandra 

I want to extract specific fields (name, loc, and ip) only.

So the result that I'm looking for is as follows:

Joan|UK|172.20.1.80
Sandra|IR|172.20.1.1

Luckily, your input file has a format the shell understands when it comes to
assigning variables a value: var1=value1 var2=value2 etc. So we can simply
read each line and use the eval command to evaluate the line.

Put the following into a file, say parse.sh, do chmod +x parse.sh and
run it with your input file as a parameter.

Script parse.sh:

#!/usr/bin/env bash

while read line; do
 eval $line;
 echo "$name|$loc|$ip"
done < "$1"

exit 0;

File input.txt:

name=Joan age=42 ip=172.20.1.80 sex=M loc=UK
loc=IR sex=F ip=172.20.1.1 age=32 name=Sandra

Run:

me@ubuntu:~> ./parse.sh input.txt 
Joan|UK|172.20.1.80
Sandra|IR|172.20.1.1

Please note that the values must not have a space in them. E.g.

ip=... name=Ubai salih loc=...

would not work and give syntax errors. Also, if the input file would contain a line with a bad_command that command gets executed because that is how eval works: it just executes the given string.

FWIW, here's a Python solution like PerlDuck's Bash solution, but not evaluating the input.

#!/usr/bin/env python3

import fileinput

for line in fileinput.input():
 record = line.rstrip('n')
 d = dict(kv.split('=') for kv in record.split(' '))
 print(d['name'], d['loc'], d['ip'], sep='|')

Run:

$ ./parse.py input.txt
Joan|UK|172.20.1.80
Sandra|IR|172.20.1.1

Since the output order that you want is reverse lexical (name > loc > ip) you could select and then reverse sort the fields, then remove the fieldname= prefixes. For example in Perl:

$ perl -alne '
 print join "|", map s/.*=//r reverse sort grep loc @F
' file
Joan|UK|172.20.1.80
Sandra|IR|172.20.1.1