I want to re-arrange a file in an order in shell - bash

Question

I have a file test.txt like below spaces in between each record
service[1.1],parttion, service[1.2],parttion, service[1.3],parttion, service[2.1],parttion, service2[2.2],parttion,
Now I want to rearrange it as below into a output.txt
COMPOSITES=parttion/service/1.1,parttion/service/1.2,parttion/service/1.3,parttion/service/2.1,parttion/service/2.2
I've tried:
final_str=''
COMPOSITES=''
# Re-arranging the composites and preparing the composite property file
while read line; do
partition_val="$(echo $line | cut -d ',' -f 2)"
composite_temp1_val="$(echo $line | cut -d ',' -f 1)"
composite_val="$(echo $composite_temp1_val | cut -d '[' -f 1)"
version_temp1_val="$(echo $composite_temp1_val | cut -d '[' -f 2)"
version_val="$(echo $version_temp1_val | cut -d ']' -f 1)"
final_str="$partition_val/$composite_val/$version_val,"
COMPOSITES=$COMPOSITES$final_str
done <./temp/test.txt

Answer 1

We start with the file:
$ cat test.txt
service[1.1],parttion, service[1.2],parttion, service[1.3],parttion, service[2.1],parttion, service2[2.2],parttion,
We can rearrange that file as follows:
$ awk -F, -v RS=" " 'BEGIN{printf "COMPOSITES=";} {gsub(/[[]/, "/"); gsub(/[]]/, ""); if (NF>1) printf "%s%s/%s",NR==1?"":",",$2,$1;}' test.txt
COMPOSITES=parttion/service/1.1,parttion/service/1.2,parttion/service/1.3,parttion/service/2.1,parttion/service2/2.2
The same command split over multiple lines is:
awk -F, -v RS=" " '
BEGIN{
printf "COMPOSITES=";
}
{
gsub(/[[]/, "/")
gsub(/[]]/, "")
if (NF>1) printf "%s%s/%s",NR==1?"":",",$2,$1
}
' test.txt

Answer 2

Here's what I came up with.
awk -F '[],[]' -v RS=" " 'BEGIN{printf("COMPOSITES=")}/../{printf("%s/%s/%s,",$4,$1,$2);}' test.txt
Broken out for easier reading:
awk -F '[],[]' -v RS=" " '
BEGIN {
printf("COMPOSITES=");
}
/../ {
printf("%s/%s/%s,",$4,$1,$2);
}' test.txt
More detailed explanation of the script:
-F '[],[]' - use commas or square brackets as field separators
-v RS=" " - use just the space as a record separator
'BEGIN{printf("COMPOSITES=")} - starts your line
/../ - run the following code on any line that has at least two characters. This avoids the empty field at the end of a line terminating with a space.
printf("%s/%s/%s,",$4,$1,$2); - print the elements using a printf() format string that matches the output you specified.
As concise as this is, the format string does leave a trailing comma at the end of the line. If this is a problem, it can be avoided with a bit of extra code.
You could also do this in sed, if you like writing code in line noise.
sed -e 's:\([^[]*\).\([^]]*\).,\([^,]*\), :\3/\1/\2,:g;s/^/COMPOSITES=/;s/,$//' test.txt
Finally, if you want to avoid external tools like sed and awk, you can do this in bash alone:
a=($(<test.txt))
echo -n "COMPOSITES="
for i in "${a[#]}"; do
i="${i%,}"
t="${i%]*}"
printf "%s/%s/%s," "${i#*,}" "${i%[*}" "${t#*[}"
done
echo ""
This slurps the contents of test.txt into an array, which means your input data must be separated by whitespace, per your example. It then adds the prefix, then steps through the array, using Parameter Expansion to massage the data into the fields you need. The last line (echo "") is helpful for testing; you may want to eliminate it in practice.