Command-line scp doesn't use case-insensitive autocomplete

Question

Auto-completing filenames (by pressing TAB after first characters of the filenames have been written) is case-sensitive both on my Ubuntu 13.04 box and on my Debian Squeeze box, when I use scp.

I have the following line in my .inputrc:

set completion-ignore-case on

and the case-insensitive autocompletion works fine on other shell programs.

Examples

<TAB> here means pressing the TAB key.

Correct behaviour

Currently, case-insensitive autocompletion works correctly on other shell programs, such as cp here:

$ cp my<TAB>

which yields, as expected:

$ cp MyFile

Incorrect behaviour

When using scp, the case-insensitive autocompletion doesn't work. On this line, nothing happens:

$ scp my<TAB>

And I have to revert to using the tedious case-sensitive autocompletion, like here:

$ scp My<TAB>

which yields, as expected:

$ scp MyFile

Possible workaround

Since this is a "recent" issue (i.e. this has been happening only for a few years or so), my guess is that this has something to do with the way some programs have autocompletable switches and other arguments, starting from some version of bash, but I'm unable to find out how to fix this specific problem.

Answer 1

Debian (and Ubuntu) install provide you with a mountain of shell completion functions (in the bash-completion package); the functions are stored in the directory /etc/bash_completion.d and the one you're interested in is /etc/bash_completion.d/ssh.

As far as I can see, the way that script gets the list of possible completions is to issue the command ls -aFld ${path}*, where ${path} is the word which needs completing, either on the remote machine -- using ssh -- or directly on the local machine.

In order for this to work in a case-insensitive manner, you need to arrange for the glob in that ls command executing on the remote system to be expanded case-insensitively, which means you want to shopt -s nocaseglob before the ls command is executed.

I think your ubuntu/debian are more recent than mine, but it's possible that the following patch will work on your system. Otherwise, you can probably figure out the necessary edit:

--- ssh.old     2013-09-17 16:07:38.000000000 -0500
+++ ssh         2013-09-17 16:06:25.000000000 -0500
@@ -275,3 +275,3 @@
         files=$( ssh -o 'Batchmode yes' $userhost \
-            command ls -aF1d "$path*" 2>/dev/null | \
+            builtin shopt -s nocaseglob ';' command ls -aF1d "$path*" 2>/dev/null | \
             sed -e 's/'$_scp_path_esc'/\\\\\\&/g' -e '/[^\/]$/d' )
@@ -281,3 +281,3 @@
         files=$( ssh -o 'Batchmode yes' $userhost \
-            command ls -aF1d "$path*" 2>/dev/null | \
+            builtin shopt -s nocaseglob ';' command ls -aF1d "$path*" 2>/dev/null | \
             sed -e 's/'$_scp_path_esc'/\\\\\\&/g' -e 's/[*@|=]$//g' \
@@ -303,6 +303,6 @@
     if $dirsonly ; then
-        COMPREPLY=( "${COMPREPLY[@]}" $( command ls -aF1d $cur* 2>/dev/null | \
+        COMPREPLY=( "${COMPREPLY[@]}" $( shopt -s nocaseglob; command ls -aF1d $cur* 2>/dev/null | \
             sed -e "s/$_scp_path_esc/\\\\&/g" -e '/[^\/]$/d' -e "s/^/$1/") )
     else
-        COMPREPLY=( "${COMPREPLY[@]}" $( command ls -aF1d $cur* 2>/dev/null | \
+        COMPREPLY=( "${COMPREPLY[@]}" $( shopt -s nocaseglob; command ls -aF1d $cur* 2>/dev/null | \
             sed -e "s/$_scp_path_esc/\\\\&/g" -e 's/[*@|=]$//g' \