Appending new column to existing files

Hi, i want to add another column to existing files containing strings and need to have the final output as a csv file. i have quite a number of files, each with varying number of rows and i need to append the string "test" for all the valid rows for each file. my sample raw files looks like this one:

123.1 12
123.2 12.1
123.3 12.2
123.4 12.3

my desired output is the one below:

test,123.1,12
test,123.2,12.1
test,123.3,12.2
test,123.4,12.3

any help and solution is greatly appreciated. thanks in advance.

awk '{gsub(/ /,",",$0); print "test,"$0}' infile

If you want to add a constant string "test" at the beginning of every string.. One way using Perl.

$ perl -lane 'unshift(@F,"test");print join(",",@F)' inputfile
test,123.1,12
test,123.2,12.1
test,123.3,12.2
test,123.4,12.3

This will work even if the columns are separated by any number of spaces (spaces, tabs).

Thank you guys, both ways very helpful as always,

Another way using sed. He, he

sed 's/^/test,/;s/ /,/' inputfile

 
sed -e 's/ /,/' -e s'/^/test,/' input.txt

hi, on the side, i need to save the new generated files into unique filenames:
if i do the loop on the final output if will be something like:

199901.csv

i want to save the final output as:

199901test.csv

how to i append the "test" part to the filename. thanks again

The below will create a file like test199901.csv

 
for i in *.csv; do sed -e 's/ /,/' -e s'/^/test,/' $i > test$i.csv; done

The below will create a file like 199901test.csv

 
for i in *.csv; do fn=$(basename $i .csv)"test.csv"; sed -e 's/ /,/' -e s'/^/test,/' $i > $fn; done

# ls -1
199901.csv
199902.csv
199903.csv
# for a in *.csv; do mv $a ${a%%.*}test.${a##*.}; done
# ls -1
199901test.csv
199902test.csv
199903test.csv