2 tv.base: add bash completion for ssh

2configs/tv/bash_completion.sh imported from bash-completion-2.1

2 files changed, 782 insertions, 0 deletions

diff --git a/2configs/tv/base.nix b/2configs/tv/base.nix
index 751a4be..0494ea0 100644
--- a/2configs/tv/base.nix
+++ b/2configs/tv/base.nix
@@ -1,5 +1,6 @@
 { config, lib, pkgs, ... }:
 
+with builtins;
 with lib;
 
 let
@@ -116,6 +117,8 @@ in
           shopt -s no_empty_cmd_completion
           complete -d cd
 
+          ${readFile ./bash_completion.sh}
+
           # TODO source bridge
         '';
         promptInit = ''
diff --git a/2configs/tv/bash_completion.sh b/2configs/tv/bash_completion.sh
new file mode 100644
index 0000000..537484f
--- /dev/null
+++ b/2configs/tv/bash_completion.sh
@@ -0,0 +1,779 @@
+
+# Expand variable starting with tilde (~)
+# We want to expand ~foo/... to /home/foo/... to avoid problems when
+# word-to-complete starting with a tilde is fed to commands and ending up
+# quoted instead of expanded.
+# Only the first portion of the variable from the tilde up to the first slash
+# (~../) is expanded.  The remainder of the variable, containing for example
+# a dollar sign variable ($) or asterisk (*) is not expanded.
+# Example usage:
+#
+#    $ v="~"; __expand_tilde_by_ref v; echo "$v"
+#
+# Example output:
+#
+#       v                  output
+#    --------         ----------------
+#    ~                /home/user
+#    ~foo/bar         /home/foo/bar
+#    ~foo/$HOME       /home/foo/$HOME
+#    ~foo/a  b        /home/foo/a  b
+#    ~foo/*           /home/foo/*
+#
+# @param $1  Name of variable (not the value of the variable) to expand
+__expand_tilde_by_ref()
+{
+    # Does $1 start with tilde (~)?
+    if [[ ${!1} == \~* ]]; then
+        # Does $1 contain slash (/)?
+        if [[ ${!1} == */* ]]; then
+            # Yes, $1 contains slash;
+            # 1: Remove * including and after first slash (/), i.e. "~a/b"
+            #    becomes "~a".  Double quotes allow eval.
+            # 2: Remove * before the first slash (/), i.e. "~a/b"
+            #    becomes "b".  Single quotes prevent eval.
+            #       +-----1----+ +---2----+
+            eval $1="${!1/%\/*}"/'${!1#*/}'
+        else
+            # No, $1 doesn't contain slash
+            eval $1="${!1}"
+        fi
+    fi
+} # __expand_tilde_by_ref()
+
+
+# Get the word to complete.
+# This is nicer than ${COMP_WORDS[$COMP_CWORD]}, since it handles cases
+# where the user is completing in the middle of a word.
+# (For example, if the line is "ls foobar",
+# and the cursor is here -------->   ^
+# @param $1 string  Characters out of $COMP_WORDBREAKS which should NOT be
+#     considered word breaks. This is useful for things like scp where
+#     we want to return host:path and not only path, so we would pass the
+#     colon (:) as $1 in this case.
+# @param $2 integer  Index number of word to return, negatively offset to the
+#     current word (default is 0, previous is 1), respecting the exclusions
+#     given at $1.  For example, `_get_cword "=:" 1' returns the word left of
+#     the current word, respecting the exclusions "=:".
+# @deprecated  Use `_get_comp_words_by_ref cur' instead
+# @see _get_comp_words_by_ref()
+_get_cword()
+{
+    local LC_CTYPE=C
+    local cword words
+    __reassemble_comp_words_by_ref "$1" words cword
+
+    # return previous word offset by $2
+    if [[ ${2//[^0-9]/} ]]; then
+        printf "%s" "${words[cword-$2]}"
+    elif [[ "${#words[cword]}" -eq 0 || "$COMP_POINT" == "${#COMP_LINE}" ]]; then
+        printf "%s" "${words[cword]}"
+    else
+        local i
+        local cur="$COMP_LINE"
+        local index="$COMP_POINT"
+        for (( i = 0; i <= cword; ++i )); do
+            while [[
+                # Current word fits in $cur?
+                "${#cur}" -ge ${#words[i]} &&
+                # $cur doesn't match cword?
+                "${cur:0:${#words[i]}}" != "${words[i]}"
+            ]]; do
+                # Strip first character
+                cur="${cur:1}"
+                # Decrease cursor position
+                ((index--))
+            done
+
+            # Does found word matches cword?
+            if [[ "$i" -lt "$cword" ]]; then
+                # No, cword lies further;
+                local old_size="${#cur}"
+                cur="${cur#${words[i]}}"
+                local new_size="${#cur}"
+                index=$(( index - old_size + new_size ))
+            fi
+        done
+
+        if [[ "${words[cword]:0:${#cur}}" != "$cur" ]]; then
+            # We messed up! At least return the whole word so things
+            # keep working
+            printf "%s" "${words[cword]}"
+        else
+            printf "%s" "${cur:0:$index}"
+        fi
+    fi
+} # _get_cword()
+
+
+# Get word previous to the current word.
+# This is a good alternative to `prev=${COMP_WORDS[COMP_CWORD-1]}' because bash4
+# will properly return the previous word with respect to any given exclusions to
+# COMP_WORDBREAKS.
+# @deprecated  Use `_get_comp_words_by_ref cur prev' instead
+# @see _get_comp_words_by_ref()
+#
+_get_pword()
+{
+    if [[ $COMP_CWORD -ge 1 ]]; then
+        _get_cword "${@:-}" 1
+    fi
+}
+
+
+
+# Complete variables.
+# @return  True (0) if variables were completed,
+#          False (> 0) if not.
+_variables()
+{
+    if [[ $cur =~ ^(\$\{?)([A-Za-z0-9_]*)$ ]]; then
+        [[ $cur == *{* ]] && local suffix=} || local suffix=
+        COMPREPLY+=( $( compgen -P ${BASH_REMATCH[1]} -S "$suffix" -v -- \
+            "${BASH_REMATCH[2]}" ) )
+        return 0
+    fi
+    return 1
+}
+
+# Assign variable one scope above the caller
+# Usage: local "$1" && _upvar $1 "value(s)"
+# Param: $1  Variable name to assign value to
+# Param: $*  Value(s) to assign.  If multiple values, an array is
+#            assigned, otherwise a single value is assigned.
+# NOTE: For assigning multiple variables, use '_upvars'.  Do NOT
+#       use multiple '_upvar' calls, since one '_upvar' call might
+#       reassign a variable to be used by another '_upvar' call.
+# See: http://fvue.nl/wiki/Bash:_Passing_variables_by_reference
+_upvar()
+{
+    if unset -v "$1"; then           # Unset & validate varname
+        if (( $# == 2 )); then
+            eval $1=\"\$2\"          # Return single value
+        else
+            eval $1=\(\"\${@:2}\"\)  # Return array
+        fi
+    fi
+}
+
+# Assign variables one scope above the caller
+# Usage: local varname [varname ...] &&
+#        _upvars [-v varname value] | [-aN varname [value ...]] ...
+# Available OPTIONS:
+#     -aN  Assign next N values to varname as array
+#     -v   Assign single value to varname
+# Return: 1 if error occurs
+# See: http://fvue.nl/wiki/Bash:_Passing_variables_by_reference
+_upvars()
+{
+    if ! (( $# )); then
+        echo "${FUNCNAME[0]}: usage: ${FUNCNAME[0]} [-v varname"\
+            "value] | [-aN varname [value ...]] ..." 1>&2
+        return 2
+    fi
+    while (( $# )); do
+        case $1 in
+            -a*)
+                # Error checking
+                [[ ${1#-a} ]] || { echo "bash: ${FUNCNAME[0]}: \`$1': missing"\
+                    "number specifier" 1>&2; return 1; }
+                printf %d "${1#-a}" &> /dev/null || { echo "bash:"\
+                    "${FUNCNAME[0]}: \`$1': invalid number specifier" 1>&2
+                    return 1; }
+                # Assign array of -aN elements
+                [[ "$2" ]] && unset -v "$2" && eval $2=\(\"\${@:3:${1#-a}}\"\) &&
+                shift $((${1#-a} + 2)) || { echo "bash: ${FUNCNAME[0]}:"\
+                    "\`$1${2+ }$2': missing argument(s)" 1>&2; return 1; }
+                ;;
+            -v)
+                # Assign single value
+                [[ "$2" ]] && unset -v "$2" && eval $2=\"\$3\" &&
+                shift 3 || { echo "bash: ${FUNCNAME[0]}: $1: missing"\
+                "argument(s)" 1>&2; return 1; }
+                ;;
+            *)
+                echo "bash: ${FUNCNAME[0]}: $1: invalid option" 1>&2
+                return 1 ;;
+        esac
+    done
+}
+
+# @param $1 exclude  Characters out of $COMP_WORDBREAKS which should NOT be
+#     considered word breaks. This is useful for things like scp where
+#     we want to return host:path and not only path, so we would pass the
+#     colon (:) as $1 in this case.
+# @param $2 words  Name of variable to return words to
+# @param $3 cword  Name of variable to return cword to
+# @param $4 cur  Name of variable to return current word to complete to
+# @see __reassemble_comp_words_by_ref()
+__get_cword_at_cursor_by_ref()
+{
+    local cword words=()
+    __reassemble_comp_words_by_ref "$1" words cword
+
+    local i cur index=$COMP_POINT lead=${COMP_LINE:0:$COMP_POINT}
+    # Cursor not at position 0 and not leaded by just space(s)?
+    if [[ $index -gt 0 && ( $lead && ${lead//[[:space:]]} ) ]]; then
+        cur=$COMP_LINE
+        for (( i = 0; i <= cword; ++i )); do
+            while [[
+                # Current word fits in $cur?
+                ${#cur} -ge ${#words[i]} &&
+                # $cur doesn't match cword?
+                "${cur:0:${#words[i]}}" != "${words[i]}"
+            ]]; do
+                # Strip first character
+                cur="${cur:1}"
+                # Decrease cursor position
+                ((index--))
+            done
+
+            # Does found word match cword?
+            if [[ $i -lt $cword ]]; then
+                # No, cword lies further;
+                local old_size=${#cur}
+                cur="${cur#"${words[i]}"}"
+                local new_size=${#cur}
+                index=$(( index - old_size + new_size ))
+            fi
+        done
+        # Clear $cur if just space(s)
+        [[ $cur && ! ${cur//[[:space:]]} ]] && cur=
+        # Zero $index if negative
+        [[ $index -lt 0 ]] && index=0
+    fi
+
+    local "$2" "$3" "$4" && _upvars -a${#words[@]} $2 "${words[@]}" \
+        -v $3 "$cword" -v $4 "${cur:0:$index}"
+}
+
+# Reassemble command line words, excluding specified characters from the
+# list of word completion separators (COMP_WORDBREAKS).
+# @param $1 chars  Characters out of $COMP_WORDBREAKS which should
+#     NOT be considered word breaks. This is useful for things like scp where
+#     we want to return host:path and not only path, so we would pass the
+#     colon (:) as $1 here.
+# @param $2 words  Name of variable to return words to
+# @param $3 cword  Name of variable to return cword to
+#
+__reassemble_comp_words_by_ref()
+{
+    local exclude i j line ref
+    # Exclude word separator characters?
+    if [[ $1 ]]; then
+        # Yes, exclude word separator characters;
+        # Exclude only those characters, which were really included
+        exclude="${1//[^$COMP_WORDBREAKS]}"
+    fi
+
+    # Default to cword unchanged
+    eval $3=$COMP_CWORD
+    # Are characters excluded which were former included?
+    if [[ $exclude ]]; then
+        # Yes, list of word completion separators has shrunk;
+        line=$COMP_LINE
+        # Re-assemble words to complete
+        for (( i=0, j=0; i < ${#COMP_WORDS[@]}; i++, j++)); do
+            # Is current word not word 0 (the command itself) and is word not
+            # empty and is word made up of just word separator characters to
+            # be excluded and is current word not preceded by whitespace in
+            # original line?
+            while [[ $i -gt 0 && ${COMP_WORDS[$i]} == +([$exclude]) ]]; do
+                # Is word separator not preceded by whitespace in original line
+                # and are we not going to append to word 0 (the command
+                # itself), then append to current word.
+                [[ $line != [$' \t']* ]] && (( j >= 2 )) && ((j--))
+                # Append word separator to current or new word
+                ref="$2[$j]"
+                eval $2[$j]=\${!ref}\${COMP_WORDS[i]}
+                # Indicate new cword
+                [[ $i == $COMP_CWORD ]] && eval $3=$j
+                # Remove optional whitespace + word separator from line copy
+                line=${line#*"${COMP_WORDS[$i]}"}
+                # Start new word if word separator in original line is
+                # followed by whitespace.
+                [[ $line == [$' \t']* ]] && ((j++))
+                # Indicate next word if available, else end *both* while and
+                # for loop
+                (( $i < ${#COMP_WORDS[@]} - 1)) && ((i++)) || break 2
+            done
+            # Append word to current word
+            ref="$2[$j]"
+            eval $2[$j]=\${!ref}\${COMP_WORDS[i]}
+            # Remove optional whitespace + word from line copy
+            line=${line#*"${COMP_WORDS[i]}"}
+            # Indicate new cword
+            [[ $i == $COMP_CWORD ]] && eval $3=$j
+        done
+        [[ $i == $COMP_CWORD ]] && eval $3=$j
+    else
+        # No, list of word completions separators hasn't changed;
+        eval $2=\( \"\${COMP_WORDS[@]}\" \)
+    fi
+} # __reassemble_comp_words_by_ref()
+
+
+# If the word-to-complete contains a colon (:), left-trim COMPREPLY items with
+# word-to-complete.
+# With a colon in COMP_WORDBREAKS, words containing
+# colons are always completed as entire words if the word to complete contains
+# a colon.  This function fixes this, by removing the colon-containing-prefix
+# from COMPREPLY items.
+# The preferred solution is to remove the colon (:) from COMP_WORDBREAKS in
+# your .bashrc:
+#
+#    # Remove colon (:) from list of word completion separators
+#    COMP_WORDBREAKS=${COMP_WORDBREAKS//:}
+#
+# See also: Bash FAQ - E13) Why does filename completion misbehave if a colon
+# appears in the filename? - http://tiswww.case.edu/php/chet/bash/FAQ
+# @param $1 current word to complete (cur)
+# @modifies global array $COMPREPLY
+#
+__ltrim_colon_completions()
+{
+    if [[ "$1" == *:* && "$COMP_WORDBREAKS" == *:* ]]; then
+        # Remove colon-word prefix from COMPREPLY items
+        local colon_word=${1%"${1##*:}"}
+        local i=${#COMPREPLY[*]}
+        while [[ $((--i)) -ge 0 ]]; do
+            COMPREPLY[$i]=${COMPREPLY[$i]#"$colon_word"}
+        done
+    fi
+} # __ltrim_colon_completions()
+
+
+# NOTE: Using this function as a helper function is deprecated.  Use
+#       `_known_hosts_real' instead.
+_known_hosts()
+{
+    local cur prev words cword
+    _init_completion -n : || return
+
+    # NOTE: Using `_known_hosts' as a helper function and passing options
+    #       to `_known_hosts' is deprecated: Use `_known_hosts_real' instead.
+    local options
+    [[ "$1" == -a || "$2" == -a ]] && options=-a
+    [[ "$1" == -c || "$2" == -c ]] && options+=" -c"
+    _known_hosts_real $options -- "$cur"
+} # _known_hosts()
+
+
+# Helper function for completing _known_hosts.
+# This function performs host completion based on ssh's config and known_hosts
+# files, as well as hostnames reported by avahi-browse if
+# COMP_KNOWN_HOSTS_WITH_AVAHI is set to a non-empty value.  Also hosts from
+# HOSTFILE (compgen -A hostname) are added, unless
+# COMP_KNOWN_HOSTS_WITH_HOSTFILE is set to an empty value.
+# Usage: _known_hosts_real [OPTIONS] CWORD
+# Options:  -a             Use aliases
+#           -c             Use `:' suffix
+#           -F configfile  Use `configfile' for configuration settings
+#           -p PREFIX      Use PREFIX
+# Return: Completions, starting with CWORD, are added to COMPREPLY[]
+_known_hosts_real()
+{
+    local configfile flag prefix
+    local cur curd awkcur user suffix aliases i host
+    local -a kh khd config
+
+    local OPTIND=1
+    while getopts "acF:p:" flag "$@"; do
+        case $flag in
+            a) aliases='yes' ;;
+            c) suffix=':' ;;
+            F) configfile=$OPTARG ;;
+            p) prefix=$OPTARG ;;
+        esac
+    done
+    [[ $# -lt $OPTIND ]] && echo "error: $FUNCNAME: missing mandatory argument CWORD"
+    cur=${!OPTIND}; let "OPTIND += 1"
+    [[ $# -ge $OPTIND ]] && echo "error: $FUNCNAME("$@"): unprocessed arguments:"\
+    $(while [[ $# -ge $OPTIND ]]; do printf '%s\n' ${!OPTIND}; shift; done)
+
+    [[ $cur == *@* ]] && user=${cur%@*}@ && cur=${cur#*@}
+    kh=()
+
+    # ssh config files
+    if [[ -n $configfile ]]; then
+        [[ -r $configfile ]] && config+=( "$configfile" )
+    else
+        for i in /etc/ssh/ssh_config ~/.ssh/config ~/.ssh2/config; do
+            [[ -r $i ]] && config+=( "$i" )
+        done
+    fi
+
+    # Known hosts files from configs
+    if [[ ${#config[@]} -gt 0 ]]; then
+        local OIFS=$IFS IFS=$'\n' j
+        local -a tmpkh
+        # expand paths (if present) to global and user known hosts files
+        # TODO(?): try to make known hosts files with more than one consecutive
+        #          spaces in their name work (watch out for ~ expansion
+        #          breakage! Alioth#311595)
+        tmpkh=( $( awk 'sub("^[ \t]*([Gg][Ll][Oo][Bb][Aa][Ll]|[Uu][Ss][Ee][Rr])[Kk][Nn][Oo][Ww][Nn][Hh][Oo][Ss][Tt][Ss][Ff][Ii][Ll][Ee][ \t]+", "") { print $0 }' "${config[@]}" | sort -u ) )
+        IFS=$OIFS
+        for i in "${tmpkh[@]}"; do
+            # First deal with quoted entries...
+            while [[ $i =~ ^([^\"]*)\"([^\"]*)\"(.*)$ ]]; do
+                i=${BASH_REMATCH[1]}${BASH_REMATCH[3]}
+                j=${BASH_REMATCH[2]}
+                __expand_tilde_by_ref j # Eval/expand possible `~' or `~user'
+                [[ -r $j ]] && kh+=( "$j" )
+            done
+            # ...and then the rest.
+            for j in $i; do
+                __expand_tilde_by_ref j # Eval/expand possible `~' or `~user'
+                [[ -r $j ]] && kh+=( "$j" )
+            done
+        done
+    fi
+
+
+    if [[ -z $configfile ]]; then
+        # Global and user known_hosts files
+        for i in /etc/ssh/ssh_known_hosts /etc/ssh/ssh_known_hosts2 \
+            /etc/known_hosts /etc/known_hosts2 ~/.ssh/known_hosts \
+            ~/.ssh/known_hosts2; do
+            [[ -r $i ]] && kh+=( "$i" )
+        done
+        for i in /etc/ssh2/knownhosts ~/.ssh2/hostkeys; do
+            [[ -d $i ]] && khd+=( "$i"/*pub )
+        done
+    fi
+
+    # If we have known_hosts files to use
+    if [[ ${#kh[@]} -gt 0 || ${#khd[@]} -gt 0 ]]; then
+        # Escape slashes and dots in paths for awk
+        awkcur=${cur//\//\\\/}
+        awkcur=${awkcur//\./\\\.}
+        curd=$awkcur
+
+        if [[ "$awkcur" == [0-9]*[.:]* ]]; then
+            # Digits followed by a dot or a colon - just search for that
+            awkcur="^$awkcur[.:]*"
+        elif [[ "$awkcur" == [0-9]* ]]; then
+            # Digits followed by no dot or colon - search for digits followed
+            # by a dot or a colon
+            awkcur="^$awkcur.*[.:]"
+        elif [[ -z $awkcur ]]; then
+            # A blank - search for a dot, a colon, or an alpha character
+            awkcur="[a-z.:]"
+        else
+            awkcur="^$awkcur"
+        fi
+
+        if [[ ${#kh[@]} -gt 0 ]]; then
+            # FS needs to look for a comma separated list
+            COMPREPLY+=( $( awk 'BEGIN {FS=","}
+            /^\s*[^|\#]/ {
+            sub("^@[^ ]+ +", ""); \
+            sub(" .*$", ""); \
+            for (i=1; i<=NF; ++i) { \
+            sub("^\\[", "", $i); sub("\\](:[0-9]+)?$", "", $i); \
+            if ($i !~ /[*?]/ && $i ~ /'"$awkcur"'/) {print $i} \
+            }}' "${kh[@]}" 2>/dev/null ) )
+        fi
+        if [[ ${#khd[@]} -gt 0 ]]; then
+            # Needs to look for files called
+            # .../.ssh2/key_22_<hostname>.pub
+            # dont fork any processes, because in a cluster environment,
+            # there can be hundreds of hostkeys
+            for i in "${khd[@]}" ; do
+                if [[ "$i" == *key_22_$curd*.pub && -r "$i" ]]; then
+                    host=${i/#*key_22_/}
+                    host=${host/%.pub/}
+                    COMPREPLY+=( $host )
+                fi
+            done
+        fi
+
+        # apply suffix and prefix
+        for (( i=0; i < ${#COMPREPLY[@]}; i++ )); do
+            COMPREPLY[i]=$prefix$user${COMPREPLY[i]}$suffix
+        done
+    fi
+
+    # append any available aliases from config files
+    if [[ ${#config[@]} -gt 0 && -n "$aliases" ]]; then
+        local hosts=$( sed -ne 's/^[ \t]*[Hh][Oo][Ss][Tt]\([Nn][Aa][Mm][Ee]\)\{0,1\}['"$'\t '"']\{1,\}\([^#*?]*\)\(#.*\)\{0,1\}$/\2/p' "${config[@]}" )
+        COMPREPLY+=( $( compgen -P "$prefix$user" \
+            -S "$suffix" -W "$hosts" -- "$cur" ) )
+    fi
+
+    # Add hosts reported by avahi-browse, if desired and it's available.
+    if [[ ${COMP_KNOWN_HOSTS_WITH_AVAHI:-} ]] && \
+        type avahi-browse &>/dev/null; then
+        # The original call to avahi-browse also had "-k", to avoid lookups
+        # into avahi's services DB. We don't need the name of the service, and
+        # if it contains ";", it may mistify the result. But on Gentoo (at
+        # least), -k wasn't available (even if mentioned in the manpage) some
+        # time ago, so...
+        COMPREPLY+=( $( compgen -P "$prefix$user" -S "$suffix" -W \
+            "$( avahi-browse -cpr _workstation._tcp 2>/dev/null | \
+                 awk -F';' '/^=/ { print $7 }' | sort -u )" -- "$cur" ) )
+    fi
+
+    # Add hosts reported by ruptime.
+    COMPREPLY+=( $( compgen -W \
+        "$( ruptime 2>/dev/null | awk '!/^ruptime:/ { print $1 }' )" \
+        -- "$cur" ) )
+
+    # Add results of normal hostname completion, unless
+    # `COMP_KNOWN_HOSTS_WITH_HOSTFILE' is set to an empty value.
+    if [[ -n ${COMP_KNOWN_HOSTS_WITH_HOSTFILE-1} ]]; then
+        COMPREPLY+=(
+            $( compgen -A hostname -P "$prefix$user" -S "$suffix" -- "$cur" ) )
+    fi
+
+    __ltrim_colon_completions "$prefix$user$cur"
+
+    return 0
+} # _known_hosts_real()
+
+
+# Get the word to complete and optional previous words.
+# This is nicer than ${COMP_WORDS[$COMP_CWORD]}, since it handles cases
+# where the user is completing in the middle of a word.
+# (For example, if the line is "ls foobar",
+# and the cursor is here -------->   ^
+# Also one is able to cross over possible wordbreak characters.
+# Usage: _get_comp_words_by_ref [OPTIONS] [VARNAMES]
+# Available VARNAMES:
+#     cur         Return cur via $cur
+#     prev        Return prev via $prev
+#     words       Return words via $words
+#     cword       Return cword via $cword
+#
+# Available OPTIONS:
+#     -n EXCLUDE  Characters out of $COMP_WORDBREAKS which should NOT be
+#                 considered word breaks. This is useful for things like scp
+#                 where we want to return host:path and not only path, so we
+#                 would pass the colon (:) as -n option in this case.
+#     -c VARNAME  Return cur via $VARNAME
+#     -p VARNAME  Return prev via $VARNAME
+#     -w VARNAME  Return words via $VARNAME
+#     -i VARNAME  Return cword via $VARNAME
+#
+# Example usage:
+#
+#    $ _get_comp_words_by_ref -n : cur prev
+#
+_get_comp_words_by_ref()
+{
+    local exclude flag i OPTIND=1
+    local cur cword words=()
+    local upargs=() upvars=() vcur vcword vprev vwords
+
+    while getopts "c:i:n:p:w:" flag "$@"; do
+        case $flag in
+            c) vcur=$OPTARG ;;
+            i) vcword=$OPTARG ;;
+            n) exclude=$OPTARG ;;
+            p) vprev=$OPTARG ;;
+            w) vwords=$OPTARG ;;
+        esac
+    done
+    while [[ $# -ge $OPTIND ]]; do
+        case ${!OPTIND} in
+            cur)   vcur=cur ;;
+            prev)  vprev=prev ;;
+            cword) vcword=cword ;;
+            words) vwords=words ;;
+            *) echo "bash: $FUNCNAME(): \`${!OPTIND}': unknown argument" \
+                1>&2; return 1
+        esac
+        let "OPTIND += 1"
+    done
+
+    __get_cword_at_cursor_by_ref "$exclude" words cword cur
+
+    [[ $vcur   ]] && { upvars+=("$vcur"  ); upargs+=(-v $vcur   "$cur"  ); }
+    [[ $vcword ]] && { upvars+=("$vcword"); upargs+=(-v $vcword "$cword"); }
+    [[ $vprev && $cword -ge 1 ]] && { upvars+=("$vprev" ); upargs+=(-v $vprev
+        "${words[cword - 1]}"); }
+    [[ $vwords ]] && { upvars+=("$vwords"); upargs+=(-a${#words[@]} $vwords
+        "${words[@]}"); }
+
+    (( ${#upvars[@]} )) && local "${upvars[@]}" && _upvars "${upargs[@]}"
+}
+
+# Initialize completion and deal with various general things: do file
+# and variable completion where appropriate, and adjust prev, words,
+# and cword as if no redirections exist so that completions do not
+# need to deal with them.  Before calling this function, make sure
+# cur, prev, words, and cword are local, ditto split if you use -s.
+#
+# Options:
+#     -n EXCLUDE  Passed to _get_comp_words_by_ref -n with redirection chars
+#     -e XSPEC    Passed to _filedir as first arg for stderr redirections
+#     -o XSPEC    Passed to _filedir as first arg for other output redirections
+#     -i XSPEC    Passed to _filedir as first arg for stdin redirections
+#     -s          Split long options with _split_longopt, implies -n =
+# @return  True (0) if completion needs further processing,
+#          False (> 0) no further processing is necessary.
+#
+_init_completion()
+{
+    local exclude= flag outx errx inx OPTIND=1
+
+    while getopts "n:e:o:i:s" flag "$@"; do
+        case $flag in
+            n) exclude+=$OPTARG ;;
+            e) errx=$OPTARG ;;
+            o) outx=$OPTARG ;;
+            i) inx=$OPTARG ;;
+            s) split=false ; exclude+== ;;
+        esac
+    done
+
+    # For some reason completion functions are not invoked at all by
+    # bash (at least as of 4.1.7) after the command line contains an
+    # ampersand so we don't get a chance to deal with redirections
+    # containing them, but if we did, hopefully the below would also
+    # do the right thing with them...
+
+    COMPREPLY=()
+    local redir="@(?([0-9])<|?([0-9&])>?(>)|>&)"
+    _get_comp_words_by_ref -n "$exclude<>&" cur prev words cword
+
+    # Complete variable names.
+    _variables && return 1
+
+    # Complete on files if current is a redirect possibly followed by a
+    # filename, e.g. ">foo", or previous is a "bare" redirect, e.g. ">".
+    if [[ $cur == $redir* || $prev == $redir ]]; then
+        local xspec
+        case $cur in
+            2'>'*) xspec=$errx ;;
+            *'>'*) xspec=$outx ;;
+            *'<'*) xspec=$inx ;;
+            *)
+                case $prev in
+                    2'>'*) xspec=$errx ;;
+                    *'>'*) xspec=$outx ;;
+                    *'<'*) xspec=$inx ;;
+                esac
+                ;;
+        esac
+        cur="${cur##$redir}"
+        _filedir $xspec
+        return 1
+    fi
+
+    # Remove all redirections so completions don't have to deal with them.
+    local i skip
+    for (( i=1; i < ${#words[@]}; )); do
+        if [[ ${words[i]} == $redir* ]]; then
+            # If "bare" redirect, remove also the next word (skip=2).
+            [[ ${words[i]} == $redir ]] && skip=2 || skip=1
+            words=( "${words[@]:0:i}" "${words[@]:i+skip}" )
+            [[ $i -le $cword ]] && cword=$(( cword - skip ))
+        else
+            i=$(( ++i ))
+        fi
+    done
+
+    [[ $cword -le 0 ]] && return 1
+    prev=${words[cword-1]}
+
+    [[ ${split-} ]] && _split_longopt && split=true
+
+    return 0
+}
+
+# Try to complete -o SubOptions=
+#
+# Returns 0 if the completion was handled or non-zero otherwise.
+_ssh_suboption_check()
+{
+    # Get prev and cur words without splitting on =
+    local cureq=`_get_cword :=` preveq=`_get_pword :=`
+    if [[ $cureq == *=* && $preveq == -o ]]; then
+        _ssh_suboption $cureq
+        return $?
+    fi
+    return 1
+}
+
+_complete_ssh()
+{
+    local cur prev words cword
+    _init_completion -n : || return
+
+    local configfile
+    local -a config
+
+    _ssh_suboption_check && return 0
+
+    case $prev in
+        -F|-i|-S)
+            _filedir
+            return 0
+            ;;
+        -c)
+            _ssh_ciphers
+            return 0
+            ;;
+        -m)
+            _ssh_macs
+            return 0
+            ;;
+        -l)
+            COMPREPLY=( $( compgen -u -- "$cur" ) )
+            return 0
+            ;;
+        -O)
+            COMPREPLY=( $( compgen -W 'check forward exit stop' -- "$cur" ) )
+            return 0
+            ;;
+        -o)
+            _ssh_options
+            return 0
+            ;;
+        -w)
+            _available_interfaces
+            return 0
+            ;;
+        -b)
+            _ip_addresses
+            return 0
+            ;;
+        -D|-e|-I|-L|-p|-R|-W)
+            return 0
+            ;;
+    esac
+
+    if [[ "$cur" == -F* ]]; then
+        cur=${cur#-F}
+        _filedir
+        # Prefix completions with '-F'
+        COMPREPLY=( "${COMPREPLY[@]/#/-F}" )
+        cur=-F$cur  # Restore cur
+    elif [[ "$cur" == -* ]]; then
+        COMPREPLY=( $( compgen -W '$( _parse_usage "$1" )' -- "$cur" ) )
+    else
+        # Search COMP_WORDS for '-F configfile' or '-Fconfigfile' argument
+        set -- "${words[@]}"
+        while [[ $# -gt 0 ]]; do
+            if [[ $1 == -F* ]]; then
+                if [[ ${#1} -gt 2 ]]; then
+                    configfile="$(dequote "${1:2}")"
+                else
+                    shift
+                    [[ $1 ]] && configfile="$(dequote "$1")"
+                fi
+                break
+            fi
+            shift
+        done
+        _known_hosts_real -a -F "$configfile" "$cur"
+        if [[ $cword -ne 1 ]]; then
+            compopt -o filenames
+            COMPREPLY+=( $( compgen -c -- "$cur" ) )
+        fi
+    fi
+
+    return 0
+} &&
+shopt -u hostcomplete && complete -F _complete_ssh ssh