how do I replace a information Fromm csv file?

Question

I have the following program

#!/bin/bash
exec 3< lista.csv
read -u 3 header
declare -i id_nou
echo "ID: "
read id_nou
while IFS=, && read -u 3 -r id nume prenume seria grupa nota
do
if [ "$id_nou" -eq "$id" ]
then
echo "Nota noua: "
read  nota_noua
nota=$nota_noua
print > lista.csv
fi
done

My csv file looks something like this:

id,nume,prenume,grupa,seria,nota

1,Ion,Andrada,1003,A,8

2,Simion,Raluca,1005,A,7

3,Gheorghita,Mihail,1009,B,5

4,Mihailescu,Georgina,1002,A,6

What I'm trying to do is replace the nota value of the correspondent's id with a given by the keyboard value, but this doesn't seem to work. The error message is

line 14: print: command not found

`print` is not a builtin program of bash. What did you want to do with it? `zsh` has an internal command of this name. — user1934428, May 23 '22 at 13:27
well my csv file has this format: id,name,surname,group,serie,grade. I want to change the grade value of a given id — Maria-Dora FOLEANU, May 23 '22 at 13:32
Please, post some sample data with the related expected output. Don't post them as comments, images, tables or links to off-site services but use text and include them to your original question. Thanks. — James Brown, May 23 '22 at 13:34
My question was: What was the supposed effect of your `print` statement? After all, you got an error message for this statement. — user1934428, May 23 '22 at 13:40
I meant to overwrite the whole line, with the modified value of nota over the current line — Maria-Dora FOLEANU, May 23 '22 at 13:49
Don't try to modify the input file during the loop. Write the output somewhere else (a temporary file) and overwrite the original at the end. — William Pursell, May 23 '22 at 13:54
thank you. do you know what command should I use to overwrite at the end? — Maria-Dora FOLEANU, May 23 '22 at 14:20

score 0 · Accepted Answer · answered May 23 '22 at 13:59

Here's one in awk:

awk 'BEGIN {
    FS=OFS=","                            # comma field separators
    printf "id: "                         # ask for id
    if((getline id < "/dev/stdin")<=0)    # store to a variable
        exit 1
    printf "nota: "                       # ...
    if((getline nota < "/dev/stdin")<=0)
        exit 1
}
$1==id {                                  # if firsst field matches
    $NF=nota                              # replace last field value
}
1' file                                   # output

Output:

id: 1
nota: THIS IS NEW VALUE
id,nume,prenume,grupa,seria,nota
1,Ion,Andrada,1003,A,THIS IS NEW VALUE
2,Simion,Raluca,1005,A,7
3,Gheorghita,Mihail,1009,B,5
4,Mihailescu,Georgina,1002,A,6

Here is some info on saving the changes.

I haven't figured out how to change the changes, can you help me out please? — Maria-Dora FOLEANU, May 24 '22 at 11:24
If you are using GNU awk: `gawk -i inplace ...`, else `awk ... file > tmp && mv tmp file`. — James Brown, May 25 '22 at 07:10

how do I replace a information Fromm csv file?

1 Answers1