Split file according to column values

Shell Programming and Scripting
1

Hi all,
I am trying to split a file by the values of the FIRST column.
The following

awk

works to split the file by the value of the LAST column -- How can I alter this to divide the column by the FIRST column??

awk -F"\t" '{ print > $NF ; close($NF)}' filename1

Thanks!

2

Replace $NF with $1

1 Like
3

any reason to why it only prints out the first line of each different Col1 value?

4

You should append to file instead because you are closing the file after each write operation:

print >> $1
1 Like
5

If I recall correctly, even > will append to a file if used in the same awk process. If you run awk several times, any instance should start a new output file with >; append with >>.
BUT: Sure it's the FIRST line per $1 value? Should it overwrite with >, I'd presume the last line is retained.

6

OR something like this

$ awk -F'\t' '{if(!($NF in F)){ print > $NF } else { print >> $NF} ; F[$NF]; close($NF)}' file