awk, sed, for in bash: Print "Hello" + Name

Question

I have a list.csv with the following content:

"date";"Mr. Green Tree"
"date";"Mr. Red Apple"
"date";"Mr. Blue Car"

I use awk + sed to get the following output:

awk -F ";" '{print $2 }' list.csv | sed 's/"//g'

Output:

Mr Green Tree
Mr Red Apple
Mr Blue Car

Now I want to use the same command in a for loop and add the string "Hello"

script.sh

get_name () {
    name=$(awk -F ";" '{print $2 }' list.csv | sed 's/"//g')
    for string in $name; do
        echo "Hello" $string
    done
}

get_name

Output when I execute script.sh:

Hello Mr
Hello Green
Hello Tree
Hello Mr
Hello Red
Hello Apple 
Hello Mr
Hello Blue
Hello Car

Expected Output:

Hello Mr Green Tree
Hello Mr Red Apple
Hello Mr Blue Car

@Daweo No, I dont think so. I have to generate a mail with this names later, e.g: Hello Mr Green Tree, here is your information (...). So I want to generate a .eml-File for each recipient (e.g. greentree@forerst.org) .. — citrusbytez, Jun 30 '22 at 11:54
Then why not directly use `sed -e 's/"//g' -e 's/^/Hello /'` or `sed -e 's/"$.*$"/Hello \1/'` — Ashok, Jun 30 '22 at 12:00
This question is closed as a duplicate of a question whose accepted answer is specific to what that user was trying to do (call other commands within the loop) but is a well known anti-pattern for people like the OP here who are not trying to do that, see [why-is-using-a-shell-loop-to-process-text-considered-bad-practice](https://unix.stackexchange.com/questions/169716/why-is-using-a-shell-loop-to-process-text-considered-bad-practice) — Ed Morton, Jun 30 '22 at 12:36

dawg · Accepted Answer · 2022-06-30T15:10:05.417

1

(Using your method...) Try:

awk -F ";" '{print $2 }' list.csv | sed 's/"//g' | while read -r line || [[ -n $line ]]; do 
    printf "Hello %s\n" "$line"
done

If you know the input will be \n terminated:

awk -F ";" '{print $2 }' list.csv | sed 's/"//g' | while read -r line; do 
    printf "Hello %s\n" "$line"
done

Bash loop from here

Or, if you looping over the file with Bash anyway, just do it all in Bash:

while IFS=';' read -r f1 f2; do 
    printf "Hello %s\n" "${f2:1:-1}" 
done <list.csv

Or (most recommended...) entirely in awk:

awk -F';' '{gsub(/"/,"",$2); print "Hello " $2}' list.csv

edited Jun 30 '22 at 15:10

answered Jun 30 '22 at 11:53

dawg

98,345
23
131
206

Only the awk script at the end will work portably, efficiently, and not corrupt the values being printed. You never need sed when you're using awk btw. `awk -F ";" '{print $2 }' list.csv | sed 's/"//g'` = `awk -F ";" '{gsub(/"/,"",$2); print $2 }' list.csv` – Ed Morton Jun 30 '22 at 12:24
So... ^1 for the awk answer at the end but not the 3 shell loops above it, I guess. – Ed Morton Jun 30 '22 at 12:37

score 0 · Answer 2 · answered Jun 30 '22 at 11:58

0

An easy way of doing it without even a for loop:

cat list.csv | awk -F ";" '{print $2 }' | sed -e 's/\.//g' | sed 's/"//g' | awk '{print "Hello"" "$1,$2,$3}'

Output:

Hello Mr Green Tree
Hello Mr Red Apple
Hello Mr Blue Car

answered Jun 30 '22 at 11:58

Apex

1,055
4
22

Working too, less complex code. I only can mark one solution. Thanks! – citrusbytez Jun 30 '22 at 12:03
2

You never need sed when you're using awk and you never need `cat` to open a file. `cat list.csv | awk -F ";" '{print $2 }' | sed -e 's/\.//g' | sed 's/"//g' | awk '{print "Hello"" "$1,$2,$3}'` = `awk -F ";" '{gsub(/[."]/,"",$2); print "Hello", $2 }' list.csv` – Ed Morton Jun 30 '22 at 12:29

score 0 · Answer 3 · answered Jun 30 '22 at 12:01

0

It works that way @dawg described, so I mark this as solution.

The suggestion from @Biffen is also working Looping through the content of a file in Bash

Code based on his answer:

get_name () {
    name=$(awk -F ";" '{print $2 }' list.csv | sed 's/"//g')
    while read p; do
        echo "Hello" $p
    done < $name
}

get_name

answered Jun 30 '22 at 12:01

citrusbytez

3
1

1

If you copy/paste your code into http://shellcheck.net it'll tell you about some of the problems with it. You should also read [why-is-using-a-shell-loop-to-process-text-considered-bad-practice](https://unix.stackexchange.com/questions/169716/why-is-using-a-shell-loop-to-process-text-considered-bad-practice) for some more important issues and to learn why not to do this. You never need sed when you're using awk btw. – Ed Morton Jun 30 '22 at 12:22

awk, sed, for in bash: Print "Hello" + Name

3 Answers3