Insert a string/number into a specific cell of a csv file - perl

Question

Basically right now I have a for loop running that runs a series of tests. Once the tests pass I input the results into a csv file:
for (( some statement ))
do
if[[ something ]]
input this value into a specific row and column
fi
done
What I can't figure out right now is how to input a specific value into a specific cell in the csv file. I know in awk you can read a cell with this command:
awk -v "row=2" -F'#' 'NR == row { print $2 }' some.csv and this will print the cell in the 2nd row and 2nd column. I need something similar to this except it can input a value into a specific cell instead of read it. Is there a function that does this?

Answer 1

You can use the following:
awk -v value=$value -v row=$row -v col=$col 'BEGIN{FS=OFS="#"} NR==row {$col=value}1' file
And set the bash values $value, $row and $col. Then you can redirect and move to the original:
awk ... file > new_file && mv new_file file
This && means that just if the first command (awk...) is executed successfully, then the second one will be performed.
Explanation
-v value=$value -v row=$row -v col=$col pass the bash variables to awk. Note value, row and col could be other names, I just used the same as bash to make it easier to understand.
BEGIN{FS=OFS="#"} set the Field Separator and Output Field Separator to be #. The OFS="#" is not necessary here, but can be useful in case you do some print.
NR==row {$col=value} when the number of record (number of line here) is equal to row, then set the col column with value value.
1 perform the default awk action: {print $0}.
Example
$ cat a
hello#how#are#you
i#am#fine#thanks
hoho#haha#hehe
$ row=2
$ col=3
$ value="XXX"
$ awk -v value=$value -v row=$row -v col=$col 'BEGIN{FS=OFS="#"} NR==row {$col=value}1' a
hello#how#are#you
i#am#XXX#thanks
hoho#haha#hehe

Answer 2

Your question has a 'perl' tag so here is a way to do it using Tie::Array::CSV which allows you to treat the CSV file as an array of arrays and use standard array operations:
use strict;
use warnings;
use Tie::Array::CSV;
my $row = 2;
my $col = 3;
my $value = 'value';
my $filename = '/path/to/file.csv';
tie my #file, 'Tie::Array::CSV', $filename, sep_char => '#';
$file[$row][$col] = $value;
untie #file;

Answer 3

using sed
row=2 # define the row number
col=3 # define the column number
value="value" # define the value you need change.
sed "$row s/[^#]\{1,\}/$value/$col" file.csv # use shell variable in sed to find row number first, then replace any word between #, and only replace the nominate column.
# So above sed command is converted to sed "2 s/[^#]\{1,\}/value/3" file.csv
If the above command is fine, and your sed command support the option -i, then run the command to change the content directly in file.csv
sed -i "$row s/[^#]\{1,\}/$value/$col" file.csv
Otherwise, you need export to temp file, and change the name back.
sed "$row s/[^#]\{1,\}/$value/$col" file.csv > temp.csv
mv temp.csv file.csv