Manipulation of file data with UNIX

Shell Programming and Scripting
1

Hello , How all doing today.. I have a little doubt in Unix

2

What have you done so far to resolve your "doubt"?

3

Just developing the thought process, can be wrong

i=0
cat file | while read line
do 
a=`echo $line | cut -d':' -f1`
b=`echo $line | cut -d':' -f2`

if [ i <= 0] then
    echo $a
    
    i++
fi
if [ i >=0 ] then 
     Then Compare $a with 1st field of next line if same the concatenate the second field
    fi
4 
awk -F: '$1!=f1 {printf("%s%s",(FNR==1)?"":ORS,$0);f1=$1;next}{printf(" %s", $2)}END{printf ORS}' myFile
5

Thanks for your support. Its just an idea
Can't it be done with and array (like hashing)

6

I don't know what you mean, but you can definitely try.....

7

I took the liberty to modify your script:

#!/bin/bash

i=0
while read line
do

a=`echo $line | cut -d':' -f1`
b=`echo $line | cut -d':' -f2`

if [  -z "${p_a}" ] || [  -z "${p_b}" ]
then
        printf "${a}:${b} "
elif [ "${a}" == "${p_a}" ]
then
        printf "${b} "
elif [ "${a}" != "${p_a}" ]
then
        printf "\n${a}:${b} "
fi

p_a=${a}
p_b=${b}

done < file