Revert the custom cobra vendor

Vendor in the latest cobra release v1.1.1

This will hurt the completion experience but is required for
proper packaging, see: #8528.

The best solution is to keep the current scripts since they
work fine with cobra v1.1.1.

Signed-off-by: Paul Holzinger <paul.holzinger@web.de>

1 files changed, 545 insertions, 207 deletions

diff --git a/vendor/github.com/spf13/cobra/bash_completions.go b/vendor/github.com/spf13/cobra/bash_completions.go
index 2ceebc552..846636d75 100644
--- a/vendor/github.com/spf13/cobra/bash_completions.go
+++ b/vendor/github.com/spf13/cobra/bash_completions.go
@@ -5,95 +5,70 @@ import (
 	"fmt"
 	"io"
 	"os"
+	"sort"
+	"strings"
+
+	"github.com/spf13/pflag"
 )
 
 // Annotations for Bash completion.
 const (
-	BashCompFilenameExt = "cobra_annotation_bash_completion_filename_extensions"
-	// BashCompCustom should be avoided as it only works for bash.
-	// Function RegisterFlagCompletionFunc() should be used instead.
+	BashCompFilenameExt     = "cobra_annotation_bash_completion_filename_extensions"
 	BashCompCustom          = "cobra_annotation_bash_completion_custom"
 	BashCompOneRequiredFlag = "cobra_annotation_bash_completion_one_required_flag"
 	BashCompSubdirsInDir    = "cobra_annotation_bash_completion_subdirs_in_dir"
 )
 
-// GenBashCompletion generates bash completion file and writes to the passed writer.
-func (c *Command) GenBashCompletion(w io.Writer) error {
-	return c.genBashCompletion(w, false)
-}
-
-// GenBashCompletionWithDesc generates bash completion file with descriptions and writes to the passed writer.
-func (c *Command) GenBashCompletionWithDesc(w io.Writer) error {
-	return c.genBashCompletion(w, true)
-}
-
-// GenBashCompletionFile generates bash completion file.
-func (c *Command) GenBashCompletionFile(filename string) error {
-	return c.genBashCompletionFile(filename, false)
-}
-
-// GenBashCompletionFileWithDesc generates bash completion file with descriptions.
-func (c *Command) GenBashCompletionFileWithDesc(filename string) error {
-	return c.genBashCompletionFile(filename, true)
+func writePreamble(buf *bytes.Buffer, name string) {
+	buf.WriteString(fmt.Sprintf("# bash completion for %-36s -*- shell-script -*-\n", name))
+	buf.WriteString(fmt.Sprintf(`
+__%[1]s_debug()
+{
+    if [[ -n ${BASH_COMP_DEBUG_FILE} ]]; then
+        echo "$*" >> "${BASH_COMP_DEBUG_FILE}"
+    fi
 }
 
-func (c *Command) genBashCompletionFile(filename string, includeDesc bool) error {
-	outFile, err := os.Create(filename)
-	if err != nil {
-		return err
-	}
-	defer outFile.Close()
-
-	return c.genBashCompletion(outFile, includeDesc)
+# Homebrew on Macs have version 1.3 of bash-completion which doesn't include
+# _init_completion. This is a very minimal version of that function.
+__%[1]s_init_completion()
+{
+    COMPREPLY=()
+    _get_comp_words_by_ref "$@" cur prev words cword
 }
 
-func (c *Command) genBashCompletion(w io.Writer, includeDesc bool) error {
-	buf := new(bytes.Buffer)
-	if len(c.BashCompletionFunction) > 0 {
-		buf.WriteString(c.BashCompletionFunction + "\n")
-	}
-	genBashComp(buf, c.Name(), includeDesc)
-
-	_, err := buf.WriteTo(w)
-	return err
+__%[1]s_index_of_word()
+{
+    local w word=$1
+    shift
+    index=0
+    for w in "$@"; do
+        [[ $w = "$word" ]] && return
+        index=$((index+1))
+    done
+    index=-1
 }
 
-func genBashComp(buf *bytes.Buffer, name string, includeDesc bool) {
-	compCmd := ShellCompRequestCmd
-	if !includeDesc {
-		compCmd = ShellCompNoDescRequestCmd
-	}
-
-	buf.WriteString(fmt.Sprintf(`# bash completion for %-36[1]s -*- shell-script -*-
-
-__%[1]s_debug()
+__%[1]s_contains_word()
 {
-    if [[ -n ${BASH_COMP_DEBUG_FILE} ]]; then
-        echo "$*" >> "${BASH_COMP_DEBUG_FILE}"
-    fi
+    local w word=$1; shift
+    for w in "$@"; do
+        [[ $w = "$word" ]] && return
+    done
+    return 1
 }
 
-__%[1]s_perform_completion()
+__%[1]s_handle_go_custom_completion()
 {
-    __%[1]s_debug
-    __%[1]s_debug "========= starting completion logic =========="
-    __%[1]s_debug "cur is ${cur}, words[*] is ${words[*]}, #words[@] is ${#words[@]}, cword is $cword"
-
-    # The user could have moved the cursor backwards on the command-line.
-    # We need to trigger completion from the $cword location, so we need
-    # to truncate the command-line ($words) up to the $cword location.
-    words=("${words[@]:0:$cword+1}")
-    __%[1]s_debug "Truncated words[*]: ${words[*]},"
+    __%[1]s_debug "${FUNCNAME[0]}: cur is ${cur}, words[*] is ${words[*]}, #words[@] is ${#words[@]}"
 
     local shellCompDirectiveError=%[3]d
     local shellCompDirectiveNoSpace=%[4]d
     local shellCompDirectiveNoFileComp=%[5]d
     local shellCompDirectiveFilterFileExt=%[6]d
     local shellCompDirectiveFilterDirs=%[7]d
-    local shellCompDirectiveLegacyCustomComp=%[8]d
-    local shellCompDirectiveLegacyCustomArgsComp=%[9]d
 
-    local out requestComp lastParam lastChar comp directive args flagPrefix
+    local out requestComp lastParam lastChar comp directive args
 
     # Prepare the command to request completions for the program.
     # Calling ${words[0]} instead of directly %[1]s allows to handle aliases
@@ -102,24 +77,16 @@ __%[1]s_perform_completion()
 
     lastParam=${words[$((${#words[@]}-1))]}
     lastChar=${lastParam:$((${#lastParam}-1)):1}
-    __%[1]s_debug "lastParam ${lastParam}, lastChar ${lastChar}"
+    __%[1]s_debug "${FUNCNAME[0]}: lastParam ${lastParam}, lastChar ${lastChar}"
 
     if [ -z "${cur}" ] && [ "${lastChar}" != "=" ]; then
         # If the last parameter is complete (there is a space following it)
         # We add an extra empty parameter so we can indicate this to the go method.
-        __%[1]s_debug "Adding extra empty parameter"
+        __%[1]s_debug "${FUNCNAME[0]}: Adding extra empty parameter"
         requestComp="${requestComp} \"\""
     fi
 
-    # When completing a flag with an = (e.g., %[1]s -n=<TAB>)
-    # bash focuses on the part after the =, so we need to remove
-    # the flag part from $cur
-    if [[ "${cur}" == -*=* ]]; then
-        flagPrefix="${cur%%%%=*}="
-        cur="${cur#*=}"
-    fi
-
-    __%[1]s_debug "Calling ${requestComp}"
+    __%[1]s_debug "${FUNCNAME[0]}: calling ${requestComp}"
     # Use eval to handle any environment variables and such
     out=$(eval "${requestComp}" 2>/dev/null)
 
@@ -131,23 +98,23 @@ __%[1]s_perform_completion()
         # There is not directive specified
         directive=0
     fi
-    __%[1]s_debug "The completion directive is: ${directive}"
-    __%[1]s_debug "The completions are: ${out[*]}"
+    __%[1]s_debug "${FUNCNAME[0]}: the completion directive is: ${directive}"
+    __%[1]s_debug "${FUNCNAME[0]}: the completions are: ${out[*]}"
 
     if [ $((directive & shellCompDirectiveError)) -ne 0 ]; then
         # Error code.  No completion.
-        __%[1]s_debug "Received error from custom completion go code"
+        __%[1]s_debug "${FUNCNAME[0]}: received error from custom completion go code"
         return
     else
         if [ $((directive & shellCompDirectiveNoSpace)) -ne 0 ]; then
             if [[ $(type -t compopt) = "builtin" ]]; then
-                __%[1]s_debug "Activating no space"
+                __%[1]s_debug "${FUNCNAME[0]}: activating no space"
                 compopt -o nospace
             fi
         fi
         if [ $((directive & shellCompDirectiveNoFileComp)) -ne 0 ]; then
             if [[ $(type -t compopt) = "builtin" ]]; then
-                __%[1]s_debug "Activating no file completion"
+                __%[1]s_debug "${FUNCNAME[0]}: activating no file completion"
                 compopt +o default
             fi
         fi
@@ -156,7 +123,6 @@ __%[1]s_perform_completion()
     if [ $((directive & shellCompDirectiveFilterFileExt)) -ne 0 ]; then
         # File extension filtering
         local fullFilter filter filteringCmd
-
         # Do not use quotes around the $out variable or else newline
         # characters will be kept.
         for filter in ${out[*]}; do
@@ -168,173 +134,545 @@ __%[1]s_perform_completion()
         $filteringCmd
     elif [ $((directive & shellCompDirectiveFilterDirs)) -ne 0 ]; then
         # File completion for directories only
-
+        local subDir
         # Use printf to strip any trailing newline
-        local subdir
         subdir=$(printf "%%s" "${out[0]}")
         if [ -n "$subdir" ]; then
             __%[1]s_debug "Listing directories in $subdir"
-            pushd "$subdir" >/dev/null 2>&1 && _filedir -d && popd >/dev/null 2>&1 || return
+            __%[1]s_handle_subdirs_in_dir_flag "$subdir"
         else
             __%[1]s_debug "Listing directories in ."
             _filedir -d
         fi
-    elif [ $((directive & shellCompDirectiveLegacyCustomComp)) -ne 0 ]; then
-        local cmd
-        __%[1]s_debug "Legacy custom completion. Directive: $directive, cmds: ${out[*]}"
-
-        # The following variables should get their value through the commands
-        # we have received as completions and are parsing below.
-        local last_command
-        local nouns
-
-        # Execute every command received
-        while IFS='' read -r cmd; do
-            __%[1]s_debug "About to execute: $cmd"
-            eval "$cmd"
-        done < <(printf "%%s\n" "${out[@]}")
-
-        __%[1]s_debug "last_command: $last_command"
-        __%[1]s_debug "nouns[0]: ${nouns[0]}, nouns[1]: ${nouns[1]}"
-
-        if [ $((directive & shellCompDirectiveLegacyCustomArgsComp)) -ne 0 ]; then
-            # We should call the global legacy custom completion function, if it is defined
-            if declare -F __%[1]s_custom_func >/dev/null; then
-                # Use command name qualified legacy custom func
-                __%[1]s_debug "About to call: __%[1]s_custom_func"
-                __%[1]s_custom_func
-            elif declare -F __custom_func >/dev/null; then
-                # Otherwise fall back to unqualified legacy custom func for compatibility
-                __%[1]s_debug "About to call: __custom_func"
-                 __custom_func
-            fi
-        fi
     else
-        local tab
-        tab=$(printf '\t')
-        local longest=0
-        # Look for the longest completion so that we can format things nicely
         while IFS='' read -r comp; do
-            comp=${comp%%%%$tab*}
-            if ((${#comp}>longest)); then
-                longest=${#comp}
+            COMPREPLY+=("$comp")
+        done < <(compgen -W "${out[*]}" -- "$cur")
+    fi
+}
+
+__%[1]s_handle_reply()
+{
+    __%[1]s_debug "${FUNCNAME[0]}"
+    local comp
+    case $cur in
+        -*)
+            if [[ $(type -t compopt) = "builtin" ]]; then
+                compopt -o nospace
+            fi
+            local allflags
+            if [ ${#must_have_one_flag[@]} -ne 0 ]; then
+                allflags=("${must_have_one_flag[@]}")
+            else
+                allflags=("${flags[*]} ${two_word_flags[*]}")
+            fi
+            while IFS='' read -r comp; do
+                COMPREPLY+=("$comp")
+            done < <(compgen -W "${allflags[*]}" -- "$cur")
+            if [[ $(type -t compopt) = "builtin" ]]; then
+                [[ "${COMPREPLY[0]}" == *= ]] || compopt +o nospace
             fi
-        done < <(printf "%%s\n" "${out[@]}")
 
-        local completions=()
-        while IFS='' read -r comp; do
-            if [ -z "$comp" ]; then
-                continue
+            # complete after --flag=abc
+            if [[ $cur == *=* ]]; then
+                if [[ $(type -t compopt) = "builtin" ]]; then
+                    compopt +o nospace
+                fi
+
+                local index flag
+                flag="${cur%%=*}"
+                __%[1]s_index_of_word "${flag}" "${flags_with_completion[@]}"
+                COMPREPLY=()
+                if [[ ${index} -ge 0 ]]; then
+                    PREFIX=""
+                    cur="${cur#*=}"
+                    ${flags_completion[${index}]}
+                    if [ -n "${ZSH_VERSION}" ]; then
+                        # zsh completion needs --flag= prefix
+                        eval "COMPREPLY=( \"\${COMPREPLY[@]/#/${flag}=}\" )"
+                    fi
+                fi
             fi
+            return 0;
+            ;;
+    esac
+
+    # check if we are handling a flag with special work handling
+    local index
+    __%[1]s_index_of_word "${prev}" "${flags_with_completion[@]}"
+    if [[ ${index} -ge 0 ]]; then
+        ${flags_completion[${index}]}
+        return
+    fi
 
-            __%[1]s_debug "Original comp: $comp"
-            comp="$(__%[1]s_format_comp_descriptions "$comp" "$longest")"
-            __%[1]s_debug "Final comp: $comp"
-            completions+=("$comp")
-        done < <(printf "%%s\n" "${out[@]}")
+    # we are parsing a flag and don't have a special handler, no completion
+    if [[ ${cur} != "${words[cword]}" ]]; then
+        return
+    fi
 
+    local completions
+    completions=("${commands[@]}")
+    if [[ ${#must_have_one_noun[@]} -ne 0 ]]; then
+        completions+=("${must_have_one_noun[@]}")
+    elif [[ -n "${has_completion_function}" ]]; then
+        # if a go completion function is provided, defer to that function
+        __%[1]s_handle_go_custom_completion
+    fi
+    if [[ ${#must_have_one_flag[@]} -ne 0 ]]; then
+        completions+=("${must_have_one_flag[@]}")
+    fi
+    while IFS='' read -r comp; do
+        COMPREPLY+=("$comp")
+    done < <(compgen -W "${completions[*]}" -- "$cur")
+
+    if [[ ${#COMPREPLY[@]} -eq 0 && ${#noun_aliases[@]} -gt 0 && ${#must_have_one_noun[@]} -ne 0 ]]; then
         while IFS='' read -r comp; do
-            # Although this script should only be used for bash
-            # there may be programs that still convert the bash
-            # script into a zsh one.  To continue supporting those
-            # programs, we do this single adaptation for zsh
-            if [ -n "${ZSH_VERSION}" ]; then
-                # zsh completion needs --flag= prefix
-                COMPREPLY+=("$flagPrefix$comp")
-            else
-                COMPREPLY+=("$comp")
-            fi
-        done < <(compgen -W "${completions[*]}" -- "$cur")
-
-        # If there is a single completion left, remove the description text
-        if [ ${#COMPREPLY[*]} -eq 1 ]; then
-            __%[1]s_debug "COMPREPLY[0]: ${COMPREPLY[0]}"
-            comp="${COMPREPLY[0]%%%% *}"
-            __%[1]s_debug "Removed description from single completion, which is now: ${comp}"
-            COMPREPLY=()
             COMPREPLY+=("$comp")
+        done < <(compgen -W "${noun_aliases[*]}" -- "$cur")
+    fi
+
+    if [[ ${#COMPREPLY[@]} -eq 0 ]]; then
+		if declare -F __%[1]s_custom_func >/dev/null; then
+			# try command name qualified custom func
+			__%[1]s_custom_func
+		else
+			# otherwise fall back to unqualified for compatibility
+			declare -F __custom_func >/dev/null && __custom_func
+		fi
+    fi
+
+    # available in bash-completion >= 2, not always present on macOS
+    if declare -F __ltrim_colon_completions >/dev/null; then
+        __ltrim_colon_completions "$cur"
+    fi
+
+    # If there is only 1 completion and it is a flag with an = it will be completed
+    # but we don't want a space after the =
+    if [[ "${#COMPREPLY[@]}" -eq "1" ]] && [[ $(type -t compopt) = "builtin" ]] && [[ "${COMPREPLY[0]}" == --*= ]]; then
+       compopt -o nospace
+    fi
+}
+
+# The arguments should be in the form "ext1|ext2|extn"
+__%[1]s_handle_filename_extension_flag()
+{
+    local ext="$1"
+    _filedir "@(${ext})"
+}
+
+__%[1]s_handle_subdirs_in_dir_flag()
+{
+    local dir="$1"
+    pushd "${dir}" >/dev/null 2>&1 && _filedir -d && popd >/dev/null 2>&1 || return
+}
+
+__%[1]s_handle_flag()
+{
+    __%[1]s_debug "${FUNCNAME[0]}: c is $c words[c] is ${words[c]}"
+
+    # if a command required a flag, and we found it, unset must_have_one_flag()
+    local flagname=${words[c]}
+    local flagvalue
+    # if the word contained an =
+    if [[ ${words[c]} == *"="* ]]; then
+        flagvalue=${flagname#*=} # take in as flagvalue after the =
+        flagname=${flagname%%=*} # strip everything after the =
+        flagname="${flagname}=" # but put the = back
+    fi
+    __%[1]s_debug "${FUNCNAME[0]}: looking for ${flagname}"
+    if __%[1]s_contains_word "${flagname}" "${must_have_one_flag[@]}"; then
+        must_have_one_flag=()
+    fi
+
+    # if you set a flag which only applies to this command, don't show subcommands
+    if __%[1]s_contains_word "${flagname}" "${local_nonpersistent_flags[@]}"; then
+      commands=()
+    fi
+
+    # keep flag value with flagname as flaghash
+    # flaghash variable is an associative array which is only supported in bash > 3.
+    if [[ -z "${BASH_VERSION}" || "${BASH_VERSINFO[0]}" -gt 3 ]]; then
+        if [ -n "${flagvalue}" ] ; then
+            flaghash[${flagname}]=${flagvalue}
+        elif [ -n "${words[ $((c+1)) ]}" ] ; then
+            flaghash[${flagname}]=${words[ $((c+1)) ]}
+        else
+            flaghash[${flagname}]="true" # pad "true" for bool flag
+        fi
+    fi
+
+    # skip the argument to a two word flag
+    if [[ ${words[c]} != *"="* ]] && __%[1]s_contains_word "${words[c]}" "${two_word_flags[@]}"; then
+			  __%[1]s_debug "${FUNCNAME[0]}: found a flag ${words[c]}, skip the next argument"
+        c=$((c+1))
+        # if we are looking for a flags value, don't show commands
+        if [[ $c -eq $cword ]]; then
+            commands=()
         fi
     fi
 
-    __%[1]s_handle_special_char "$cur" :
-    __%[1]s_handle_special_char "$cur" =
+    c=$((c+1))
+
 }
 
-__%[1]s_handle_special_char()
+__%[1]s_handle_noun()
 {
-    local comp="$1"
-    local char=$2
-    if [[ "$comp" == *${char}* && "$COMP_WORDBREAKS" == *${char}* ]]; then
-        local word=${comp%%"${comp##*${char}}"}
-        local idx=${#COMPREPLY[*]}
-        while [[ $((--idx)) -ge 0 ]]; do
-            COMPREPLY[$idx]=${COMPREPLY[$idx]#"$word"}
-        done
+    __%[1]s_debug "${FUNCNAME[0]}: c is $c words[c] is ${words[c]}"
+
+    if __%[1]s_contains_word "${words[c]}" "${must_have_one_noun[@]}"; then
+        must_have_one_noun=()
+    elif __%[1]s_contains_word "${words[c]}" "${noun_aliases[@]}"; then
+        must_have_one_noun=()
     fi
+
+    nouns+=("${words[c]}")
+    c=$((c+1))
 }
 
-__%[1]s_format_comp_descriptions()
+__%[1]s_handle_command()
 {
-    local tab
-    tab=$(printf '\t')
-    local comp="$1"
-    local longest=$2
-
-    # Properly format the description string which follows a tab character if there is one
-    if [[ "$comp" == *$tab* ]]; then
-        desc=${comp#*$tab}
-        comp=${comp%%%%$tab*}
-
-        # $COLUMNS stores the current shell width.
-        # Remove an extra 4 because we add 2 spaces and 2 parentheses.
-        maxdesclength=$(( COLUMNS - longest - 4 ))
-
-        # Make sure we can fit a description of at least 8 characters
-        # if we are to align the descriptions.
-        if [[ $maxdesclength -gt 8 ]]; then
-            # Add the proper number of spaces to align the descriptions
-            for ((i = ${#comp} ; i < longest ; i++)); do
-                comp+=" "
-            done
+    __%[1]s_debug "${FUNCNAME[0]}: c is $c words[c] is ${words[c]}"
+
+    local next_command
+    if [[ -n ${last_command} ]]; then
+        next_command="_${last_command}_${words[c]//:/__}"
+    else
+        if [[ $c -eq 0 ]]; then
+            next_command="_%[1]s_root_command"
         else
-            # Don't pad the descriptions so we can fit more text after the completion
-            maxdesclength=$(( COLUMNS - ${#comp} - 4 ))
+            next_command="_${words[c]//:/__}"
         fi
+    fi
+    c=$((c+1))
+    __%[1]s_debug "${FUNCNAME[0]}: looking for ${next_command}"
+    declare -F "$next_command" >/dev/null && $next_command
+}
 
-        # If there is enough space for any description text,
-        # truncate the descriptions that are too long for the shell width
-        if [ $maxdesclength -gt 0 ]; then
-            if [ ${#desc} -gt $maxdesclength ]; then
-                desc=${desc:0:$(( maxdesclength - 1 ))}
-                desc+="…"
-            fi
-            comp+="  ($desc)"
+__%[1]s_handle_word()
+{
+    if [[ $c -ge $cword ]]; then
+        __%[1]s_handle_reply
+        return
+    fi
+    __%[1]s_debug "${FUNCNAME[0]}: c is $c words[c] is ${words[c]}"
+    if [[ "${words[c]}" == -* ]]; then
+        __%[1]s_handle_flag
+    elif __%[1]s_contains_word "${words[c]}" "${commands[@]}"; then
+        __%[1]s_handle_command
+    elif [[ $c -eq 0 ]]; then
+        __%[1]s_handle_command
+    elif __%[1]s_contains_word "${words[c]}" "${command_aliases[@]}"; then
+        # aliashash variable is an associative array which is only supported in bash > 3.
+        if [[ -z "${BASH_VERSION}" || "${BASH_VERSINFO[0]}" -gt 3 ]]; then
+            words[c]=${aliashash[${words[c]}]}
+            __%[1]s_handle_command
+        else
+            __%[1]s_handle_noun
         fi
+    else
+        __%[1]s_handle_noun
     fi
+    __%[1]s_handle_word
+}
 
-    # Must use printf to escape all special characters
-    printf "%%q" "${comp}"
+`, name, ShellCompNoDescRequestCmd,
+		ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
+		ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs))
 }
 
-__start_%[1]s()
-{
+func writePostscript(buf *bytes.Buffer, name string) {
+	name = strings.Replace(name, ":", "__", -1)
+	buf.WriteString(fmt.Sprintf("__start_%s()\n", name))
+	buf.WriteString(fmt.Sprintf(`{
     local cur prev words cword
+    declare -A flaghash 2>/dev/null || :
+    declare -A aliashash 2>/dev/null || :
+    if declare -F _init_completion >/dev/null 2>&1; then
+        _init_completion -s || return
+    else
+        __%[1]s_init_completion -n "=" || return
+    fi
 
-    COMPREPLY=()
-    _get_comp_words_by_ref -n "=:" cur prev words cword
-
-    __%[1]s_perform_completion
+    local c=0
+    local flags=()
+    local two_word_flags=()
+    local local_nonpersistent_flags=()
+    local flags_with_completion=()
+    local flags_completion=()
+    local commands=("%[1]s")
+    local must_have_one_flag=()
+    local must_have_one_noun=()
+    local has_completion_function
+    local last_command
+    local nouns=()
+
+    __%[1]s_handle_word
 }
 
-if [[ $(type -t compopt) = "builtin" ]]; then
-    complete -o default -F __start_%[1]s %[1]s
+`, name))
+	buf.WriteString(fmt.Sprintf(`if [[ $(type -t compopt) = "builtin" ]]; then
+    complete -o default -F __start_%s %s
 else
-    complete -o default -o nospace -F __start_%[1]s %[1]s
+    complete -o default -o nospace -F __start_%s %s
 fi
 
-# ex: ts=4 sw=4 et filetype=sh
-`, name, compCmd,
-		ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
-		ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs,
-		shellCompDirectiveLegacyCustomComp, shellCompDirectiveLegacyCustomArgsComp))
+`, name, name, name, name))
+	buf.WriteString("# ex: ts=4 sw=4 et filetype=sh\n")
+}
+
+func writeCommands(buf *bytes.Buffer, cmd *Command) {
+	buf.WriteString("    commands=()\n")
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() && c != cmd.helpCommand {
+			continue
+		}
+		buf.WriteString(fmt.Sprintf("    commands+=(%q)\n", c.Name()))
+		writeCmdAliases(buf, c)
+	}
+	buf.WriteString("\n")
+}
+
+func writeFlagHandler(buf *bytes.Buffer, name string, annotations map[string][]string, cmd *Command) {
+	for key, value := range annotations {
+		switch key {
+		case BashCompFilenameExt:
+			buf.WriteString(fmt.Sprintf("    flags_with_completion+=(%q)\n", name))
+
+			var ext string
+			if len(value) > 0 {
+				ext = fmt.Sprintf("__%s_handle_filename_extension_flag ", cmd.Root().Name()) + strings.Join(value, "|")
+			} else {
+				ext = "_filedir"
+			}
+			buf.WriteString(fmt.Sprintf("    flags_completion+=(%q)\n", ext))
+		case BashCompCustom:
+			buf.WriteString(fmt.Sprintf("    flags_with_completion+=(%q)\n", name))
+			if len(value) > 0 {
+				handlers := strings.Join(value, "; ")
+				buf.WriteString(fmt.Sprintf("    flags_completion+=(%q)\n", handlers))
+			} else {
+				buf.WriteString("    flags_completion+=(:)\n")
+			}
+		case BashCompSubdirsInDir:
+			buf.WriteString(fmt.Sprintf("    flags_with_completion+=(%q)\n", name))
+
+			var ext string
+			if len(value) == 1 {
+				ext = fmt.Sprintf("__%s_handle_subdirs_in_dir_flag ", cmd.Root().Name()) + value[0]
+			} else {
+				ext = "_filedir -d"
+			}
+			buf.WriteString(fmt.Sprintf("    flags_completion+=(%q)\n", ext))
+		}
+	}
+}
+
+func writeShortFlag(buf *bytes.Buffer, flag *pflag.Flag, cmd *Command) {
+	name := flag.Shorthand
+	format := "    "
+	if len(flag.NoOptDefVal) == 0 {
+		format += "two_word_"
+	}
+	format += "flags+=(\"-%s\")\n"
+	buf.WriteString(fmt.Sprintf(format, name))
+	writeFlagHandler(buf, "-"+name, flag.Annotations, cmd)
+}
+
+func writeFlag(buf *bytes.Buffer, flag *pflag.Flag, cmd *Command) {
+	name := flag.Name
+	format := "    flags+=(\"--%s"
+	if len(flag.NoOptDefVal) == 0 {
+		format += "="
+	}
+	format += "\")\n"
+	buf.WriteString(fmt.Sprintf(format, name))
+	if len(flag.NoOptDefVal) == 0 {
+		format = "    two_word_flags+=(\"--%s\")\n"
+		buf.WriteString(fmt.Sprintf(format, name))
+	}
+	writeFlagHandler(buf, "--"+name, flag.Annotations, cmd)
+}
+
+func writeLocalNonPersistentFlag(buf *bytes.Buffer, flag *pflag.Flag) {
+	name := flag.Name
+	format := "    local_nonpersistent_flags+=(\"--%[1]s\")\n"
+	if len(flag.NoOptDefVal) == 0 {
+		format += "    local_nonpersistent_flags+=(\"--%[1]s=\")\n"
+	}
+	buf.WriteString(fmt.Sprintf(format, name))
+	if len(flag.Shorthand) > 0 {
+		buf.WriteString(fmt.Sprintf("    local_nonpersistent_flags+=(\"-%s\")\n", flag.Shorthand))
+	}
+}
+
+// Setup annotations for go completions for registered flags
+func prepareCustomAnnotationsForFlags(cmd *Command) {
+	for flag := range flagCompletionFunctions {
+		// Make sure the completion script calls the __*_go_custom_completion function for
+		// every registered flag.  We need to do this here (and not when the flag was registered
+		// for completion) so that we can know the root command name for the prefix
+		// of __<prefix>_go_custom_completion
+		if flag.Annotations == nil {
+			flag.Annotations = map[string][]string{}
+		}
+		flag.Annotations[BashCompCustom] = []string{fmt.Sprintf("__%[1]s_handle_go_custom_completion", cmd.Root().Name())}
+	}
+}
+
+func writeFlags(buf *bytes.Buffer, cmd *Command) {
+	prepareCustomAnnotationsForFlags(cmd)
+	buf.WriteString(`    flags=()
+    two_word_flags=()
+    local_nonpersistent_flags=()
+    flags_with_completion=()
+    flags_completion=()
+
+`)
+	localNonPersistentFlags := cmd.LocalNonPersistentFlags()
+	cmd.NonInheritedFlags().VisitAll(func(flag *pflag.Flag) {
+		if nonCompletableFlag(flag) {
+			return
+		}
+		writeFlag(buf, flag, cmd)
+		if len(flag.Shorthand) > 0 {
+			writeShortFlag(buf, flag, cmd)
+		}
+		// localNonPersistentFlags are used to stop the completion of subcommands when one is set
+		// if TraverseChildren is true we should allow to complete subcommands
+		if localNonPersistentFlags.Lookup(flag.Name) != nil && !cmd.Root().TraverseChildren {
+			writeLocalNonPersistentFlag(buf, flag)
+		}
+	})
+	cmd.InheritedFlags().VisitAll(func(flag *pflag.Flag) {
+		if nonCompletableFlag(flag) {
+			return
+		}
+		writeFlag(buf, flag, cmd)
+		if len(flag.Shorthand) > 0 {
+			writeShortFlag(buf, flag, cmd)
+		}
+	})
+
+	buf.WriteString("\n")
+}
+
+func writeRequiredFlag(buf *bytes.Buffer, cmd *Command) {
+	buf.WriteString("    must_have_one_flag=()\n")
+	flags := cmd.NonInheritedFlags()
+	flags.VisitAll(func(flag *pflag.Flag) {
+		if nonCompletableFlag(flag) {
+			return
+		}
+		for key := range flag.Annotations {
+			switch key {
+			case BashCompOneRequiredFlag:
+				format := "    must_have_one_flag+=(\"--%s"
+				if flag.Value.Type() != "bool" {
+					format += "="
+				}
+				format += "\")\n"
+				buf.WriteString(fmt.Sprintf(format, flag.Name))
+
+				if len(flag.Shorthand) > 0 {
+					buf.WriteString(fmt.Sprintf("    must_have_one_flag+=(\"-%s\")\n", flag.Shorthand))
+				}
+			}
+		}
+	})
+}
+
+func writeRequiredNouns(buf *bytes.Buffer, cmd *Command) {
+	buf.WriteString("    must_have_one_noun=()\n")
+	sort.Sort(sort.StringSlice(cmd.ValidArgs))
+	for _, value := range cmd.ValidArgs {
+		// Remove any description that may be included following a tab character.
+		// Descriptions are not supported by bash completion.
+		value = strings.Split(value, "\t")[0]
+		buf.WriteString(fmt.Sprintf("    must_have_one_noun+=(%q)\n", value))
+	}
+	if cmd.ValidArgsFunction != nil {
+		buf.WriteString("    has_completion_function=1\n")
+	}
+}
+
+func writeCmdAliases(buf *bytes.Buffer, cmd *Command) {
+	if len(cmd.Aliases) == 0 {
+		return
+	}
+
+	sort.Sort(sort.StringSlice(cmd.Aliases))
+
+	buf.WriteString(fmt.Sprint(`    if [[ -z "${BASH_VERSION}" || "${BASH_VERSINFO[0]}" -gt 3 ]]; then`, "\n"))
+	for _, value := range cmd.Aliases {
+		buf.WriteString(fmt.Sprintf("        command_aliases+=(%q)\n", value))
+		buf.WriteString(fmt.Sprintf("        aliashash[%q]=%q\n", value, cmd.Name()))
+	}
+	buf.WriteString(`    fi`)
+	buf.WriteString("\n")
+}
+func writeArgAliases(buf *bytes.Buffer, cmd *Command) {
+	buf.WriteString("    noun_aliases=()\n")
+	sort.Sort(sort.StringSlice(cmd.ArgAliases))
+	for _, value := range cmd.ArgAliases {
+		buf.WriteString(fmt.Sprintf("    noun_aliases+=(%q)\n", value))
+	}
+}
+
+func gen(buf *bytes.Buffer, cmd *Command) {
+	for _, c := range cmd.Commands() {
+		if !c.IsAvailableCommand() && c != cmd.helpCommand {
+			continue
+		}
+		gen(buf, c)
+	}
+	commandName := cmd.CommandPath()
+	commandName = strings.Replace(commandName, " ", "_", -1)
+	commandName = strings.Replace(commandName, ":", "__", -1)
+
+	if cmd.Root() == cmd {
+		buf.WriteString(fmt.Sprintf("_%s_root_command()\n{\n", commandName))
+	} else {
+		buf.WriteString(fmt.Sprintf("_%s()\n{\n", commandName))
+	}
+
+	buf.WriteString(fmt.Sprintf("    last_command=%q\n", commandName))
+	buf.WriteString("\n")
+	buf.WriteString("    command_aliases=()\n")
+	buf.WriteString("\n")
+
+	writeCommands(buf, cmd)
+	writeFlags(buf, cmd)
+	writeRequiredFlag(buf, cmd)
+	writeRequiredNouns(buf, cmd)
+	writeArgAliases(buf, cmd)
+	buf.WriteString("}\n\n")
+}
+
+// GenBashCompletion generates bash completion file and writes to the passed writer.
+func (c *Command) GenBashCompletion(w io.Writer) error {
+	buf := new(bytes.Buffer)
+	writePreamble(buf, c.Name())
+	if len(c.BashCompletionFunction) > 0 {
+		buf.WriteString(c.BashCompletionFunction + "\n")
+	}
+	gen(buf, c)
+	writePostscript(buf, c.Name())
+
+	_, err := buf.WriteTo(w)
+	return err
+}
+
+func nonCompletableFlag(flag *pflag.Flag) bool {
+	return flag.Hidden || len(flag.Deprecated) > 0
+}
+
+// GenBashCompletionFile generates bash completion file.
+func (c *Command) GenBashCompletionFile(filename string) error {
+	outFile, err := os.Create(filename)
+	if err != nil {
+		return err
+	}
+	defer outFile.Close()
+
+	return c.GenBashCompletion(outFile)
 }