cobra/bash_completions.go
Ville Skyttä 3d8ac432bd
Micro-optimizations (#1957)
* Avoid redundant string splits

There likely isn't actually more than once to split in the source
strings in these cases, but avoid doing so anyway as we're only
interested in the first.

* Avoid redundant completion output target evaluations

The target is not to be changed while outputting completions, so resolve
it only once.

* Avoid redundant active help enablement evaluations

The enablement state is not to be changed during completion output, so
evaluate it only once.

* Preallocate some slices and maps with known size

* Avoid some unnecessary looping

* Use strings.Builder to construct suggestions
2023-11-23 12:24:33 -05:00

713 lines
22 KiB
Go

// Copyright 2013-2023 The Cobra Authors
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
package cobra
import (
"bytes"
"fmt"
"io"
"os"
"sort"
"strings"
"github.com/spf13/pflag"
)
// Annotations for Bash completion.
const (
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"
)
func writePreamble(buf io.StringWriter, name string) {
WriteStringAndCheck(buf, fmt.Sprintf("# bash completion for %-36s -*- shell-script -*-\n", name))
WriteStringAndCheck(buf, fmt.Sprintf(`
__%[1]s_debug()
{
if [[ -n ${BASH_COMP_DEBUG_FILE:-} ]]; then
echo "$*" >> "${BASH_COMP_DEBUG_FILE}"
fi
}
# Homebrew on Macs have version 1.3 of bash-completion which doesn't include
# _init_completion. This is a very minimal version of that function.
__%[1]s_init_completion()
{
COMPREPLY=()
_get_comp_words_by_ref "$@" cur prev words cword
}
__%[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
}
__%[1]s_contains_word()
{
local w word=$1; shift
for w in "$@"; do
[[ $w = "$word" ]] && return
done
return 1
}
__%[1]s_handle_go_custom_completion()
{
__%[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 out requestComp lastParam lastChar comp directive args
# Prepare the command to request completions for the program.
# Calling ${words[0]} instead of directly %[1]s allows handling aliases
args=("${words[@]:1}")
# Disable ActiveHelp which is not supported for bash completion v1
requestComp="%[8]s=0 ${words[0]} %[2]s ${args[*]}"
lastParam=${words[$((${#words[@]}-1))]}
lastChar=${lastParam:$((${#lastParam}-1)):1}
__%[1]s_debug "${FUNCNAME[0]}: lastParam ${lastParam}, lastChar ${lastChar}"
if [ -z "${cur}" ] && [ "${lastChar}" != "=" ]; then
# If the last parameter is complete (there is a space following it)
# We add an extra empty parameter so we can indicate this to the go method.
__%[1]s_debug "${FUNCNAME[0]}: Adding extra empty parameter"
requestComp="${requestComp} \"\""
fi
__%[1]s_debug "${FUNCNAME[0]}: calling ${requestComp}"
# Use eval to handle any environment variables and such
out=$(eval "${requestComp}" 2>/dev/null)
# Extract the directive integer at the very end of the output following a colon (:)
directive=${out##*:}
# Remove the directive
out=${out%%:*}
if [ "${directive}" = "${out}" ]; then
# There is not directive specified
directive=0
fi
__%[1]s_debug "${FUNCNAME[0]}: the completion directive is: ${directive}"
__%[1]s_debug "${FUNCNAME[0]}: the completions are: ${out}"
if [ $((directive & shellCompDirectiveError)) -ne 0 ]; then
# Error code. No completion.
__%[1]s_debug "${FUNCNAME[0]}: received error from custom completion go code"
return
else
if [ $((directive & shellCompDirectiveNoSpace)) -ne 0 ]; then
if [[ $(type -t compopt) = "builtin" ]]; then
__%[1]s_debug "${FUNCNAME[0]}: activating no space"
compopt -o nospace
fi
fi
if [ $((directive & shellCompDirectiveNoFileComp)) -ne 0 ]; then
if [[ $(type -t compopt) = "builtin" ]]; then
__%[1]s_debug "${FUNCNAME[0]}: activating no file completion"
compopt +o default
fi
fi
fi
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 ${out}; do
fullFilter+="$filter|"
done
filteringCmd="_filedir $fullFilter"
__%[1]s_debug "File filtering command: $filteringCmd"
$filteringCmd
elif [ $((directive & shellCompDirectiveFilterDirs)) -ne 0 ]; then
# File completion for directories only
local subdir
# Use printf to strip any trailing newline
subdir=$(printf "%%s" "${out}")
if [ -n "$subdir" ]; then
__%[1]s_debug "Listing directories in $subdir"
__%[1]s_handle_subdirs_in_dir_flag "$subdir"
else
__%[1]s_debug "Listing directories in ."
_filedir -d
fi
else
while IFS='' read -r comp; do
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
# 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
if [[ -z "${flag_parsing_disabled}" ]]; then
# If flag parsing is enabled, we have completed the flags and can return.
# If flag parsing is disabled, we may not know all (or any) of the flags, so we fallthrough
# to possibly call handle_go_custom_completion.
return 0;
fi
;;
esac
# check if we are handling a flag with special work handling
local index
__%[1]s_index_of_word "${prev}" "${flags_with_completion[@]}"
if [[ ${index} -ge 0 ]]; then
${flags_completion[${index}]}
return
fi
# 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 && ${#must_have_one_noun[@]} -ne 0 ]]; then
while IFS='' read -r comp; do
COMPREPLY+=("$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 $cword ]]; then
commands=()
fi
fi
c=$((c+1))
}
__%[1]s_handle_noun()
{
__%[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=$((c+1))
}
__%[1]s_handle_command()
{
__%[1]s_debug "${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 [[ $c -eq 0 ]]; then
next_command="_%[1]s_root_command"
else
next_command="_${words[c]//:/__}"
fi
fi
c=$((c+1))
__%[1]s_debug "${FUNCNAME[0]}: looking for ${next_command}"
declare -F "$next_command" >/dev/null && $next_command
}
__%[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
}
`, name, ShellCompNoDescRequestCmd,
ShellCompDirectiveError, ShellCompDirectiveNoSpace, ShellCompDirectiveNoFileComp,
ShellCompDirectiveFilterFileExt, ShellCompDirectiveFilterDirs, activeHelpEnvVar(name)))
}
func writePostscript(buf io.StringWriter, name string) {
name = strings.ReplaceAll(name, ":", "__")
WriteStringAndCheck(buf, fmt.Sprintf("__start_%s()\n", name))
WriteStringAndCheck(buf, fmt.Sprintf(`{
local cur prev words cword split
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
local c=0
local flag_parsing_disabled=
local flags=()
local two_word_flags=()
local local_nonpersistent_flags=()
local flags_with_completion=()
local flags_completion=()
local commands=("%[1]s")
local command_aliases=()
local must_have_one_flag=()
local must_have_one_noun=()
local has_completion_function=""
local last_command=""
local nouns=()
local noun_aliases=()
__%[1]s_handle_word
}
`, name))
WriteStringAndCheck(buf, fmt.Sprintf(`if [[ $(type -t compopt) = "builtin" ]]; then
complete -o default -F __start_%s %s
else
complete -o default -o nospace -F __start_%s %s
fi
`, name, name, name, name))
WriteStringAndCheck(buf, "# ex: ts=4 sw=4 et filetype=sh\n")
}
func writeCommands(buf io.StringWriter, cmd *Command) {
WriteStringAndCheck(buf, " commands=()\n")
for _, c := range cmd.Commands() {
if !c.IsAvailableCommand() && c != cmd.helpCommand {
continue
}
WriteStringAndCheck(buf, fmt.Sprintf(" commands+=(%q)\n", c.Name()))
writeCmdAliases(buf, c)
}
WriteStringAndCheck(buf, "\n")
}
func writeFlagHandler(buf io.StringWriter, name string, annotations map[string][]string, cmd *Command) {
for key, value := range annotations {
switch key {
case BashCompFilenameExt:
WriteStringAndCheck(buf, 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"
}
WriteStringAndCheck(buf, fmt.Sprintf(" flags_completion+=(%q)\n", ext))
case BashCompCustom:
WriteStringAndCheck(buf, fmt.Sprintf(" flags_with_completion+=(%q)\n", name))
if len(value) > 0 {
handlers := strings.Join(value, "; ")
WriteStringAndCheck(buf, fmt.Sprintf(" flags_completion+=(%q)\n", handlers))
} else {
WriteStringAndCheck(buf, " flags_completion+=(:)\n")
}
case BashCompSubdirsInDir:
WriteStringAndCheck(buf, 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"
}
WriteStringAndCheck(buf, fmt.Sprintf(" flags_completion+=(%q)\n", ext))
}
}
}
const cbn = "\")\n"
func writeShortFlag(buf io.StringWriter, flag *pflag.Flag, cmd *Command) {
name := flag.Shorthand
format := " "
if len(flag.NoOptDefVal) == 0 {
format += "two_word_"
}
format += "flags+=(\"-%s" + cbn
WriteStringAndCheck(buf, fmt.Sprintf(format, name))
writeFlagHandler(buf, "-"+name, flag.Annotations, cmd)
}
func writeFlag(buf io.StringWriter, flag *pflag.Flag, cmd *Command) {
name := flag.Name
format := " flags+=(\"--%s"
if len(flag.NoOptDefVal) == 0 {
format += "="
}
format += cbn
WriteStringAndCheck(buf, fmt.Sprintf(format, name))
if len(flag.NoOptDefVal) == 0 {
format = " two_word_flags+=(\"--%s" + cbn
WriteStringAndCheck(buf, fmt.Sprintf(format, name))
}
writeFlagHandler(buf, "--"+name, flag.Annotations, cmd)
}
func writeLocalNonPersistentFlag(buf io.StringWriter, flag *pflag.Flag) {
name := flag.Name
format := " local_nonpersistent_flags+=(\"--%[1]s" + cbn
if len(flag.NoOptDefVal) == 0 {
format += " local_nonpersistent_flags+=(\"--%[1]s=" + cbn
}
WriteStringAndCheck(buf, fmt.Sprintf(format, name))
if len(flag.Shorthand) > 0 {
WriteStringAndCheck(buf, fmt.Sprintf(" local_nonpersistent_flags+=(\"-%s\")\n", flag.Shorthand))
}
}
// prepareCustomAnnotationsForFlags setup annotations for go completions for registered flags
func prepareCustomAnnotationsForFlags(cmd *Command) {
flagCompletionMutex.RLock()
defer flagCompletionMutex.RUnlock()
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 io.StringWriter, cmd *Command) {
prepareCustomAnnotationsForFlags(cmd)
WriteStringAndCheck(buf, ` flags=()
two_word_flags=()
local_nonpersistent_flags=()
flags_with_completion=()
flags_completion=()
`)
if cmd.DisableFlagParsing {
WriteStringAndCheck(buf, " flag_parsing_disabled=1\n")
}
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)
}
})
WriteStringAndCheck(buf, "\n")
}
func writeRequiredFlag(buf io.StringWriter, cmd *Command) {
WriteStringAndCheck(buf, " 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 += cbn
WriteStringAndCheck(buf, fmt.Sprintf(format, flag.Name))
if len(flag.Shorthand) > 0 {
WriteStringAndCheck(buf, fmt.Sprintf(" must_have_one_flag+=(\"-%s"+cbn, flag.Shorthand))
}
}
}
})
}
func writeRequiredNouns(buf io.StringWriter, cmd *Command) {
WriteStringAndCheck(buf, " must_have_one_noun=()\n")
sort.Strings(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.SplitN(value, "\t", 2)[0]
WriteStringAndCheck(buf, fmt.Sprintf(" must_have_one_noun+=(%q)\n", value))
}
if cmd.ValidArgsFunction != nil {
WriteStringAndCheck(buf, " has_completion_function=1\n")
}
}
func writeCmdAliases(buf io.StringWriter, cmd *Command) {
if len(cmd.Aliases) == 0 {
return
}
sort.Strings(cmd.Aliases)
WriteStringAndCheck(buf, fmt.Sprint(` if [[ -z "${BASH_VERSION:-}" || "${BASH_VERSINFO[0]:-}" -gt 3 ]]; then`, "\n"))
for _, value := range cmd.Aliases {
WriteStringAndCheck(buf, fmt.Sprintf(" command_aliases+=(%q)\n", value))
WriteStringAndCheck(buf, fmt.Sprintf(" aliashash[%q]=%q\n", value, cmd.Name()))
}
WriteStringAndCheck(buf, ` fi`)
WriteStringAndCheck(buf, "\n")
}
func writeArgAliases(buf io.StringWriter, cmd *Command) {
WriteStringAndCheck(buf, " noun_aliases=()\n")
sort.Strings(cmd.ArgAliases)
for _, value := range cmd.ArgAliases {
WriteStringAndCheck(buf, fmt.Sprintf(" noun_aliases+=(%q)\n", value))
}
}
func gen(buf io.StringWriter, cmd *Command) {
for _, c := range cmd.Commands() {
if !c.IsAvailableCommand() && c != cmd.helpCommand {
continue
}
gen(buf, c)
}
commandName := cmd.CommandPath()
commandName = strings.ReplaceAll(commandName, " ", "_")
commandName = strings.ReplaceAll(commandName, ":", "__")
if cmd.Root() == cmd {
WriteStringAndCheck(buf, fmt.Sprintf("_%s_root_command()\n{\n", commandName))
} else {
WriteStringAndCheck(buf, fmt.Sprintf("_%s()\n{\n", commandName))
}
WriteStringAndCheck(buf, fmt.Sprintf(" last_command=%q\n", commandName))
WriteStringAndCheck(buf, "\n")
WriteStringAndCheck(buf, " command_aliases=()\n")
WriteStringAndCheck(buf, "\n")
writeCommands(buf, cmd)
writeFlags(buf, cmd)
writeRequiredFlag(buf, cmd)
writeRequiredNouns(buf, cmd)
writeArgAliases(buf, cmd)
WriteStringAndCheck(buf, "}\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)
}