augeas.txt

[ ] is for creating lenses (tree nodes)

del /:\s+/ ": " means that there might be several spaces but we want only one when reconstructing?

file.aug:16.56-.71 exception on line 16, col 56 to 71 (the line is omitted since it remains the same)

let lens is forbidden, use let lns instead

No ~ in filter! Only absolute paths

Don't try to not store

a label doesn't consume text from the concrete view. So if you expect a lens to produce { "<<" = "production" }, you need to use [ key "<<" ... ]

labels are only produced in the abstract view

the tree is composed of nodes
each node can have a label (a), an optional value (b), and optional children (c)

[ key "a" . store "b" . [ key "c" ] ] will parse "abc" as { "a" = "b" { "c" } }

Example:
augtool -I . ls /files/path/to/file.yml/host1/

augtool -I . -At "YAML incl '/home/xxx/bla.yml'" print '/augeas//error'
or
augtool -I . -At "YAML incl '/home/xxx/bla.yml'" errors

note:
if running in non-interactive mode, you won't be able to access the errors as kept in RAM.
Instead:
augtool> your_command
augtool> errors