[Help-bash] Behavior of 'complete -o filenames' unclear

[Michael Siegel]

Hello,

I'm out of ideas on how to solve a problem in an auto-completion script
I've written. The problem is with the behavior of 'complete -o
filenames'.

Here's the script:


# dbm_completion_bash
#
# Auto-completion for dbm in Bash

_dbm_complete_bash() {

  local IFS=$'\n'
  local dbm_dir="$HOME/.dbm"

  # Only perform bookmark name completion on the first argument to dbm,
        # except when that first argument is '-d' (the delete switch). In that
        # case, perform bookmark name completion on any given argument (in
        # effect: on any argument supplied to '-d').
  if [ "address@hidden" -lt 3 ] || [ "${COMP_WORDS[1]}" = '-d' ]
  then
    # Complete the current word, based on file names in $dbm_dir, and
                # cut the directory prefix.
    COMPREPLY=($(compgen -f -- "$dbm_dir/${COMP_WORDS[COMP_CWORD]}" | \
    cut -d '/' -f 5))
  fi
}

complete -o filenames -F _dbm_complete_bash dbm
# -o filenames: Perform escaping of shell special characters.


To give some background: dbm is a simple directory bookmarking system
for the shell, implemented as a set of shell functions that are sourced
in ~/.bashrc. The completion script given above is sourced in the file
containing the dbm function set. Bookmarks are simply symbolic links
inside ~/.dbm.

Running dbm without arguments will simply display the existing bookmarks
and their destinations in the file system:

~$ dbm
dbm -> /home/msi/devel/shell/dbm
msiism -> /home/msi/devel/www/msiism
sand box -> /home/msi/devel/sandbox

To jump to a bookmarked location, you'd invoke dbm with the respective
bookmark name as an argument. Having that argument completed when you
hit <Tab> generally works, except for one particular situation. And that
is when there is a directory of the same name as the completed bookmark
name in the current working directory.

In that case, the shell will add a slash to the name, as if it were
completing directory names within $PWD:

~/devel/sandbox/probe$ ls
a_file  msiism/  tests/
~/devel/sandbox/probe$ dbm msi<Tab>  # Results in 'dbm msiism/'
~/devel/sandbox/probe$

Now, the Bash Reference Manual does say that '-o filename' will "perform
any filename-specific processing"[1], "like adding a slash to directory
names"[1] and such. What I don't understand is why it is still adding
the slash when completion is based on file names in $dbm_dir instead of
$PWD.

Any ideas?


Thanks,

msi


[1]
https://www.gnu.org/software/bash/manual/html_node/Programmable-Completion-Builtins.html