Linux split a file in two columns - linux

Question

I have the following file that contains 2 columns :
A:B:IP:80 apples
C:D:IP2:82 oranges
E:F:IP3:84 grapes
How is possible to split the file in 2 other files, each column in a file like this:
File1
A:B:IP:80
C:D:IP2:82
E:F:IP3:84
File2
apples
oranges
grapes

Answer 1

Try:
awk '{print $1>"file1"; print $2>"file2"}' file
After runningl that command, we can verify that the desired files have been created:
$ cat file1
A:B:IP:80
C:D:IP2:82
E:F:IP3:84
And:
$ cat file2
apples
oranges
grapes
How it works
print $1>"file1"
This tells awk to write the first column to file1.
print $2>"file2"
This tells awk to write the second column to file2.

Answer 2

Perl 1-liner using (abusing) the fact that print goes to STDOUT, i.e. file descriptor 1, and warn goes to STDERR, i.e. file descriptor 2:
# perl -n means loop over the lines of input automatically
# perl -e means execute the following code
# chomp means remove the trailing newline from the expression
perl -ne 'chomp(my #cols = split /\s+/); # Split each line on whitespace
print $cols[0] . "\n";
warn $cols[1] . "\n"' <input 1>col1 2>col2
You could, of course, just use cut -b with the appropriate columns, but then you would need to read the file twice.

Answer 3

Here's an awk solution that'll work with any number of columns:
awk '{for(n=1;n<=NF;n++)print $n>"File"n}' input.txt
This steps through each field on the line and prints the field to a different output file based on the column number.
Note that blank fields -- or rather, lines with fewer fields than other lines, will cause line numbers to mismatch. That is, if your input is:
A 1
B
C 3
Then File2 will contain:
1
3
If this is a concern, mention it in an update to your question.
You could of course do this in bash alone, in a number of ways. Here's one:
while read -r line; do
a=($line)
for m in "${!a[#]}"; do
printf '%s\n' "${a[$m]}" >> File$((m+1))
done
done < input.txt
This reads each line of input into $line, then word-splits $line into values in the $a[] array. It then steps through that array, printing each item to the appropriate file, named for the index of the array (plus one, since bash arrays start at zero).