bash string manipulation - regex match with delimiter - bash

Question

I have a string like this:
zone=INTERNET|status=good|routed=special|location=001|resp=user|switch=not set|stack=no|dswres=no|CIDR=10.10.10.0/24|allowDuplicateHost=disable|inheritAllowDuplicateHost=true|pingBeforeAssign=enable|inheritPingBeforeAssign=true|locationInherited=true|gateway=10.10.10.100|inheritDefaultDomains=true|inheritDefaultView=true|inheritDNSRestrictions=true|name=SCB-INET-A
The order inside the delimiter | can be random - that means the key-value pairs can be randomly ordered in the string.
I want an output string like the following:
"INTERNET","10.10.10.0/24","SCB-INET-A"
All values in the output are values from the key-value string above
Does anyone know how I can solve this with awk or sed?

Answer 1

Given your input is a variable var:
var="zone=INTERNET|status=good|routed=special|location=001|resp=user|switch=not set|stack=no|dswres=no|CIDR=10.10.10.0/24|allowDuplicateHost=disable|inheritAllowDuplicateHost=true|pingBeforeAssign=enable|inheritPingBeforeAssign=true|locationInherited=true|gateway=10.10.10.100|inheritDefaultDomains=true|inheritDefaultView=true|inheritDNSRestrictions=true|name=SCB-INET-A"
echo "$var" | tr "|" "\n" | sed -n -r "s/(zone|name|gateway)=(.*)/\"\2\"/p"
"INTERNET"
"10.10.10.100"
"SCB-INET-A"
Using another 2 pipes inserts commas and removes line breaks:
SOFAR | tr "\n" "," | sed 's/,$//'
"INTERNET","10.10.10.100","SCB-INET-A"

Answer 2

Whenever you have name -> value pairs in your input the best approach is to create an array of those mappings (f[] below) and then access the values by their names:
$ cat tst.awk
BEGIN { RS="|"; FS="[=\n]"; OFS="," }
{ f[$1] = "\"" $2 "\"" }
END { print f["zone"], f["CIDR"], f["name"] }
$ awk -f tst.awk file
"INTERNET","10.10.10.0/24","SCB-INET-A"
The above will work efficiently (i.e. literally orders of magnitude faster than a shell loop) and portably using any awk in any shell on any UNIX box, unlike all of the other answers so far which all rely on non-POSIX functionality. It does full string matching instead of partial regexp matching, like some of the other answers, so it is extremely robust and will not result in bad output given partial matches. It also will not interpret any input characters (e.g. escape sequences and/or globbing chars), like some of your other answers do, and instead will just robustly reproduce them as-is in the output.
If you need to enhance it to print any extra field values just add them as , f["<field name>"] to the print statement and if you need to change the output format or do anything else it's all absolutely trivial too.

Answer 3

Using awk:
var="zone=INTERNET|status=good|routed=special|location=001|resp=user|switch=not set|stack=no|dswres=no|CIDR=10.10.10.0/24|allowDuplicateHost=disable|inheritAllowDuplicateHost=true|pingBeforeAssign=enable|inheritPingBeforeAssign=true|locationInherited=true|gateway=10.10.10.100|inheritDefaultDomains=true|inheritDefaultView=true|name=SCB-INET-A|inheritDNSRestrictions=true"
awk -v RS='|' -v ORS=',' -F= '$1~/zone|gateway|name/{print "\"" $2 "\""}' <<<"$var" | sed 's/,$//'
"INTERNET","10.10.10.100","SCB-INET-A"
The input record separator RS is set to |.
The input field separator FS is set to =.
The output record separator ORS is set to ,.
$1~/zone|gateway|name/ is filtering the parameter to extract. The print statement is added double quote to the parameter value.
The sed statement is to remove the annoying last , (that the print statement is adding).

Answer 4

One more solution using Bash. Not the shortest but I hope it is the best readable and so the best maintainable.
#!/bin/bash
# Function split_key_val()
# selects values from a string with key-value pairs
# IN: string_with_key_value_pairs wanted_key_1 [wanted_key_2] ...
# OUT: result
function split_key_val {
local KEY_VAL_STRING="$1"
local RESULT
# read the string with key-value pairs into array
IFS=\| read -r -a ARRAY <<< "$KEY_VAL_STRING"
#
shift
# while there are wanted-keys ...
while [[ -n $1 ]]
do
WANTED_KEY="$1"
# Search the array for the wanted-key
for KEY_VALUE in "${ARRAY[#]}"
do
# the key is the part before "="
KEY=$(echo "$KEY_VALUE" |cut --delimiter="=" --fields=1)
# the value is the part after "="
VALUE=$(echo "$KEY_VALUE" |cut --delimiter="=" --fields=2)
if [[ $KEY == $WANTED_KEY ]]
then
# if result is empty; result= found value...
if [[ -z $RESULT ]]
then
# (quote the damned quotes)
RESULT="\"${VALUE}\""
else
# ... else add a comma as a separator
RESULT="${RESULT},\"${VALUE}\""
fi
fi # key == wanted-key
done # searched whole array
shift # prepare for next wanted-key
done
echo "$RESULT"
return 0
}
STRING="zone=INTERNET|status=good|routed=special|location=001|resp=user|switch=not set|stack=no|dswres=no|CIDR=10.10.10.0/24|allowDuplicateHost=disable|inheritAllowDuplicateHost=true|pingBeforeAssign=enable|inheritPingBeforeAssign=true|locationInherited=true|gateway=10.10.10.100|inheritDefaultDomains=true|inheritDefaultView=true|inheritDNSRestrictions=true|name=SCB-INET-A"
split_key_val "$STRING" zone CIDR name
The result is:
"INTERNET","10.10.10.0/24","SCB-INET-A"

Answer 5

without using more sophisticated text editing tools (as an exercise!)
$ tr '|' '\n' <file | # make it columnar
egrep '^(zone|CIDR|name)=' | # get exact key matches
cut -d= -f2 | # get values
while read line; do echo '"'$line'"'; done | # quote values
paste -sd, # flatten with comma
will give
"INTERNET","10.10.10.0/24","SCB-INET-A"
you can also replace while statement with xargs printf '"%s"\n'

Answer 6

Not using sed or awk but the Bash Arrays feature.
line="zone=INTERNET|sta=good|CIDR=10.10.10.0/24|a=1 1|...=...|name=SCB-INET-A"
echo "$line" | tr '|' '\n' | {
declare -A vars
while read -r item ; do
if [ -n "$item" ] ; then
vars["${item%%=*}"]="${item##*=}"
fi
done
echo "\"${vars[zone]}\",\"${vars[CIDR]}\",\"${vars[name]}\"" ; }
One advantage of this method is that you always get your fields in order independent of the order of fields in the input line.