zk/docs/external-processing.md

Send notes for processing by other programs

A great way to expand zk feature set is to explore a wealth of command-line tools available. You can use zk's powerful searching and filtering capabilities to select notes before delegating further processing to other programs.

Process file paths

Many programs expect file paths for input. You can interface with such program using the path list format and a space delimiter.

$ zk list --format path --delimiter " "

If the file paths can contain spaces, you may want to quote manually the paths, using the {{path}} template variable instead:

$ zk list --format "'{{path}}'" --delimiter " "

As always, this is such a useful command alias to have:

paths = "zk list --format \"'{{path}}'\" --quiet --delimiter ' ' $@"

Some programs – such as xargs – work better when file paths are separated by the ASCII NUL character (\0). In this case, you can use the --delimiter0 (or -0) option.

For example, this command prints the full Git history of the notes:

$ zk list --format path --delimiter0 | xargs -0 git log --patch --

Feeding zk to itself

Some zk options such as --exclude also take file paths for parameters. Let's increase their flexibility by nesting zk calls. In this case, the delimiter will be ,.

For example, this command lists the notes which are linked by at least one other note – so the notes which are not orphans.

$ zk list --exclude "`zk list -q -f path -d "," --orphan`"

And this one finds the notes which are linked by at least one note in journal/.

$ zk list --linked-by "`zk list -q -f path -d "," journal`"

Process the content of a note

If you want to directly transform the content instead, you may use the raw-content template variable, which will print the full content of the note file.

In this particular case, we usually want to process only one note at a time. You can make sure that zk list will print only the first note from the result with --limit 1 (or -n1).

$ zk list --format {{raw-content}} --limit 1