Let's take this as a sample input file:
$ cat file
jim|process1|23
bob|process2|5
jim|process3|7
Using awk
Now, let's create this shell script:
$ cat script.sh
#!/bin/sh
read -p "Please Enter a UserName: " uname
awk -v n="$uname" -F\| '$1==n{total+=$3} END{printf "Total for %s is %s minutes\n",n,total}' file
As an example, let's sum up the time used by jim:
$ sh script.sh
Please Enter a UserName: jim
Total for jim is 30 minutes
How it works
awk implicitly loops through every line in the input file. This script uses two variables: n which is the user name and total which is the running total of minutes used by user n.
-v n="$uname"
This creates an awk variable n and assigns to it the value of the shell variable uname.
-F\|
This tells awk to use | as the field separator
$1==n{total+=$3}
Every time the first field, $1, matches the user name, n, we increment the total total by the amount of the third field, $3.
END{printf "Total for %s is %s minutes\n",n,total}
When we are done reading the file, we print out the result.
Using shell
Alternatively, we can do the looping in shell:
$ cat script2.sh
#!/bin/sh
read -p "Please Enter a UserName: " uname
while IFS=\| read -r name process minutes; do
[ "$name" = "$uname" ] && total=$((total+minutes))
done <file
echo "Total for $uname is $total minutes"
As a demonstration:
$ sh script2.sh
Please Enter a UserName: jim
Total for jim is 30 minutes
I haven't timed the two approaches but I expect that awk will be much faster.
