Remove all text before colon

Question

I have a file containing a certain number of lines. Each line looks like this:

TF_list_to_test10004/Nus_k0.345_t0.1_         


        

Answer 1

Here are two ways of doing it in R:

foo <- "TF_list_to_test10004/Nus_k0.345_t0.1_e0.1.adj:PKMYT1"

# Remove all before and up to ":":
gsub(".*:","",foo)

# Extract everything behind ":":
regmatches(foo,gregexpr("(?<=:).*",foo,perl=TRUE))

Answer 2

Using sed:

sed 's/.*://' < your_input_file > output_file

This will replace anything followed by a colon with nothing, so it'll remove everything up to and including the last colon on each line (because * is greedy by default).

As per Josh O'Brien's comment, if you wanted to only replace up to and including the first colon, do this:

sed "s/[^:]*://"

That will match anything that isn't a colon, followed by one colon, and replace with nothing.

Note that for both of these patterns they'll stop on the first match on each line. If you want to make a replace happen for every match on a line, add the 'g' (global) option to the end of the command.

Also note that on linux (but not on OSX) you can edit a file in-place with -i eg:

sed -i 's/.*://' your_file

Answer 3

If you have GNU coreutils available use cut:

cut -d: -f2 infile