Joining Line-Delimited Data

The Perl join function is nice, because you can join a list to create a scalar value with a delimiter. For example, if I have a line-delimited list of names:

bob
joe
mary

I might want to have a comma-separated list, which I can do with sed:

$ sed -e ':a; N; s/\n/,/; ta' <<EOF
> bob
> joe
> mary
> EOF
bob,joe,mary

In general, where DELIM is your desired delimiter:

sed -e ':a; N; s/\n/DELIM/; ta'