Adding data from an array to a new column in a file using bash

Question

So I have Name age and city data:

name=(Alex Barbara Connor Daniel Matt Peter Stan)
age=(22 23 55 32 21 8 89)
city=(London Manchester Rome Alberta Naples Detroit Amsterdam)

and I want to set up the following as 3 column data with the headings Name Age and city, I can easily get the first column using

touch info.txt
echo "Name Age City" > info.txt
for n in ${name[@]}; do
    echo $n >> info.txt
done

but I can't figure how to get the rest of the data, and I can't seem to find anywhere on how to add data that's different as a new column.

Any help would be greatly appreciated, thank you.

JoseLinares · Accepted Answer · 2021-02-12T11:51:51.290

3

Try something like this:

name=(Alex Barbara Connor Daniel Matt Peter Stan)
age=(22 23 55 32 21 8 89)
city=(London Manchester Rome Alberta Naples Detroit Amsterdam)

touch info.txt
echo "Name Age City" > info.txt
for n in $(seq 0 6); do
    echo ${name[$n]} ${age[$n]} ${city[$n]} >> info.txt
done

Output in info.txt:

Name Age City
Alex 22 London
Barbara 23 Manchester
Connor 55 Rome
Daniel 32 Alberta
Matt 21 Naples
Peter 8 Detroit
Stan 89 Amsterdam

edited Feb 12 '21 at 11:51

answered Feb 11 '21 at 18:06

JoseLinares

775
5
15

2

An alternative loop: `for ((n=0; n<${#name[@]}; n++))` – Cyrus Feb 11 '21 at 18:15
1

you can also use printf instead of echo to fix the width. check my answer below. Nice work – Aven Desta Feb 11 '21 at 18:16
2

@Cyrus `for n in "${!name[@]}"` would be more idiomatic. – oguz ismail Feb 11 '21 at 18:30
1

This is exactly what I needed thank you! I'm very new to bash and new I needed some way to get numbers 1->7 but couldn't find anything so huge thank you! – user15192788 Feb 12 '21 at 10:49
@user15192788 just take into account that the array index starts in 0, not in 1. So it should be $(seq 0 6) . I just edited my answer to fix this. – JoseLinares Feb 12 '21 at 11:53

Aven Desta · Answer 2 · 2021-02-11T18:21:30.453

You can fix a specific width for each column (here 20 is used)

name=(Alex Barbara Connor Daniel Matt Peter Stan)
age=(22 23 55 32 21 8 89)
city=(London Manchester Rome Alberta Naples Detroit Amsterdam)

for i in "${!name[@]}"; do
    printf "%-20s %-20s %-20s\n" "${name[i]}" "${age[i]}" "${city[i]}"
done

Output:

Alex                 22                   London              
Barbara              23                   Manchester          
Connor               55                   Rome                
Daniel               32                   Alberta             
Matt                 21                   Naples              
Peter                8                    Detroit             
Stan                 89                   Amsterdam

score 1 · Answer 3 · answered Feb 11 '21 at 18:17

JoseLinares solved your problem. For your information, here is a solution with the paste command whose purpose is exactly that: putting data from different sources in separate columns.

$ printf 'Name\tAge\tCity\n'
$ paste <(printf '%s\n' "${name[@]}") \
        <(printf '%3d\n' "${age[@]}") \
        <(printf '%s\n' "${city[@]}")

Name    Age City
Alex     22 London
Barbara  23 Manchester
Connor   55 Rome
Daniel   32 Alberta
Matt     21 Naples
Peter     8 Detroit
Stan     89 Amsterdam

Adding data from an array to a new column in a file using bash

3 Answers3