Turn comma-separate rows into 1 column

Question

I have a list of users basically from /etc/group, Id like to basically format that line into one column, I just need the users. So if a field looks like this:

bob,john,jane,sam,joyce

Then I'd like it to look like this

bob
john
jane
sam
joyce

I know how to do the opposite but not this type.

Answer 1

You can do this with sed:

sed 's/,/\n/g'

This replaces all occurrences of , with a newline. g makes sed replace all the occurrences in a line instead of just the first.

Answer 2

To answer using your suggested tags:

bash:

$ IFS=, read -a names <<< "bob,john,jane,sam,joyce"
$ printf "%s\n" "${names[@]}"
bob
john
jane
sam
joyce

awk:

$ echo "bob,john,jane,sam,joyce" | awk -F, -v OFS="\n" '{$1=$1; print}'
bob
john
jane
sam
joyce

The $1=$1 bit is an awk idiom to rewrite the current record using the Output Field Separators, which does not happen unless some field is modified.

Answer 3

You could do this with a find and replace in vim:

:%s/,/\r/g

See this question...

Answer 4

A few options:

tr:

tr ',' '\n' < [input file] > [output file]

tr is a tool that filters its standard input and replaces every occurrence of a character from its first argument with the matching one from the second element, then prints to standard out.

vim/ex (this will work in a script):

vim -c "%s/,/\r/g" -c "wq" [input file]

The -c option tells vim to run the following ex command (same as what you would type after a : when using vim normally).

And someone already beat me to sed.

Answer 5

If you would like to use awk (similar to Print all Fields with AWK separated by OFS):

echo "bob,john,jane,sam,joyce" | awk  'BEGIN {FS=","; OFS="\n"} {$1=$1; print $0}'