How to add pattern to bash completion (for unzip)?

Question

When I type

unzip <tab>

I get a list of all files ending in .zip, which is the standard behavior of tab completion for the unzip command.

However, I also want bash completion for unzip list files which end in .udp, in addition to .zip files. How can I achieve this behavior in my local .bashrc?

Answer 1

Instead of keeping on commenting …

---

complete -f -X '!*.@(zip|udp)' unzip

should add completion for

-f -X '!*.@(zip|udp)'
 |  |  | |||________|
 |  |  | ||     |
 |  |  | ||     +- filterpat: zip or udp
 |  |  | |+-------------  @ : Matches one of the given patterns
 |  |  | +-------------- *. : Anything+<dot>
 |  |  +----------------  ! : Negate
 |  +------------------- -X : Filter out matches in "filterpat"
 +---------------------- -f : files

In other words: Complete files and remove all not ending in .zip or .udp.

---

Extras

If you add -o default completion will complete/match all files and directories if there is no files ending in .zip or .udp.

If you add -o plusdirs completion will add any directories in addition to any matches of files ending in .zip or .udp.

Current

When you use complete -p unzip you get current pattern.

From your comments it sounds mostly like you are missing either + or @ in pattern, as in:

# Err:
complete -f -X '!*.(zip|udp)' unzip
                   |
                   +---- Missing + or @

which would mean match any file literally ending in .(zip|udp). E.g.

touch 'file_test.(zip|udp)'

Also have a look at this section of the manual:

• 3.5.8 Filename Expansion
• 4.3.2 The Shopt Builtin

it is possible e.g. extglob is not enabled. Enable by:

shopt -s extglob

Check current status of all shopt settings by entering:

shopt

---

Function

If that is -F something it means it uses a function named something to generate the list of completions.

The _filedir_xspec is typically a Debian function. You might have something like this:

$ cat /etc/bash_completion
. /usr/share/bash-completion/bash_completion

Which means /usr/share/bash-completion/bash_completion get sourced. Here you'll find the function in question. A few lines further down you see that this function / completion is added by a function named _install_xspec by e.g.:

_install_xspec '!*.@(zip|[ejsw]ar|exe|pk3|wsz|zargo|xpi|s[tx][cdiw]|sx[gm]|o[dt][tspgfc]|od[bm]|oxt|epub|apk|do[ct][xm]|p[op]t[mx]|xl[st][xm])' unzip zipinfo

---

Manual entries:

• 8.7 Programmable Completion Builtins
• 3.5.8.1 Pattern Matching

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Update to comments 1:

– No match due to invalid archives or file permissions.

This should not affect the result. complete only matches files given by the rules and do no processing of the files. If you can list them with ls, they should match.

As a side note one could add such a functionality by using a complete function:

function _unzip_validated() {
    # 1. Generate list of files ending in e.g. .zip and .udp
    # 2. Validate each file and remove invalid ones from file list.
}

complete -F _unzip_validated unzip

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– Colors. Why does ls distinguish test.zip from test.upd?

This does not affect complete. Colors by ls are provided by $LS_COLORS. Try:

echo "$LS_COLORS" | tr : '\n' | sort

You should see something like *.zip=01;31 which means:

*.zip=01;31
|____| |  |
   |   |  +--- Red
   |   +------ Bold
   +---------- Files with .zip extension

*.udp on the other hand has no entry associated with it, so no coloring.

---

Next step (should have been first)

1. Open terminal and go to a directory with test files. Both .zip and .udp
2. Enter bash --norc
3. Enter complete -f -X '!*.@(zip|udp)' unzip
4. Enter shopt -s extglob
5. Enter unzip <tab><tab>

Result?

Also, click edit below your question and add output of:

bind -V
shopt
env

might be helpful.

Answer 2

In the file /etc/bash_completion, which you are presumably sourcing somewhere, the default completion, at least for my version of bash (v4.2.25) is

complete -f -X '!*.@(zip|[ejw]ar|exe|pk3|wsz|zargo|xpi|sxw|o[tx]t|od[fgpst]|epub|apk)' unzip zipinfo

Try changing the entire expression to

complete -f -X '!*.@(zip|[ejw]ar|exe|pk3|wsz|zargo|xpi|sxw|o[tx]t|od[fgpst]|epub|apk|udp)' unzip zipinfo

And add to your .bash_profile

Answer 3

Try adding this line in your .bashrc:

complete -f -o default -X '!*.+(zip|udp)' unzip

Answer 4

Better use _filedir instead of "raw" complete.

Justification

• grep _filedir -r $(pkg-config --variable=completionsdir bash-completion) | wc -l
• tilde (~) paths are being expanded
• Prefixes are removed for directories, i.e. for /home/tux/Do<TAB><TAB>, the list you get as a reply removes '/home/tux' and is thus much more compact
• Easier to implement and more failsafe

MWE

_unzip_completor()
{
    # init bash-completion's stuff
    _init_completion || return

    # fill COMPREPLY using bash-completion's routine
    _filedir '@(zip|udp)'
}
complete -F _unzip_completor unzip