summaryrefslogtreecommitdiff
path: root/vendor/github.com/spf13/cobra/bash_completions.md
diff options
context:
space:
mode:
Diffstat (limited to 'vendor/github.com/spf13/cobra/bash_completions.md')
-rw-r--r--vendor/github.com/spf13/cobra/bash_completions.md306
1 files changed, 7 insertions, 299 deletions
diff --git a/vendor/github.com/spf13/cobra/bash_completions.md b/vendor/github.com/spf13/cobra/bash_completions.md
index e61a3a654..a82d5bb8b 100644
--- a/vendor/github.com/spf13/cobra/bash_completions.md
+++ b/vendor/github.com/spf13/cobra/bash_completions.md
@@ -1,206 +1,14 @@
-# Generating Bash Completions For Your Own cobra.Command
+# Generating Bash Completions For Your cobra.Command
-If you are using the generator you can create a completion command by running
+Please refer to [Shell Completions](shell_completions.md) for details.
-```bash
-cobra add completion
-```
-
-Update the help text show how to install the bash_completion Linux show here [Kubectl docs show mac options](https://kubernetes.io/docs/tasks/tools/install-kubectl/#enabling-shell-autocompletion)
-
-Writing the shell script to stdout allows the most flexible use.
-
-```go
-// completionCmd represents the completion command
-var completionCmd = &cobra.Command{
- Use: "completion",
- Short: "Generates bash completion scripts",
- Long: `To load completion run
-
-. <(bitbucket completion)
-
-To configure your bash shell to load completions for each session add to your bashrc
-
-# ~/.bashrc or ~/.profile
-. <(bitbucket completion)
-`,
- Run: func(cmd *cobra.Command, args []string) {
- rootCmd.GenBashCompletion(os.Stdout);
- },
-}
-```
-
-**Note:** The cobra generator may include messages printed to stdout for example if the config file is loaded, this will break the auto complete script
-
-
-## Example from kubectl
-
-Generating bash completions from a cobra command is incredibly easy. An actual program which does so for the kubernetes kubectl binary is as follows:
-
-```go
-package main
-
-import (
- "io/ioutil"
- "os"
-
- "k8s.io/kubernetes/pkg/kubectl/cmd"
- "k8s.io/kubernetes/pkg/kubectl/cmd/util"
-)
-
-func main() {
- kubectl := cmd.NewKubectlCommand(util.NewFactory(nil), os.Stdin, ioutil.Discard, ioutil.Discard)
- kubectl.GenBashCompletionFile("out.sh")
-}
-```
-
-`out.sh` will get you completions of subcommands and flags. Copy it to `/etc/bash_completion.d/` as described [here](https://debian-administration.org/article/316/An_introduction_to_bash_completion_part_1) and reset your terminal to use autocompletion. If you make additional annotations to your code, you can get even more intelligent and flexible behavior.
-
-## Have the completions code complete your 'nouns'
-
-### Static completion of nouns
-
-This method allows you to provide a pre-defined list of completion choices for your nouns using the `validArgs` field.
-For example, if you want `kubectl get [tab][tab]` to show a list of valid "nouns" you have to set them. Simplified code from `kubectl get` looks like:
-
-```go
-validArgs []string = { "pod", "node", "service", "replicationcontroller" }
-
-cmd := &cobra.Command{
- Use: "get [(-o|--output=)json|yaml|template|...] (RESOURCE [NAME] | RESOURCE/NAME ...)",
- Short: "Display one or many resources",
- Long: get_long,
- Example: get_example,
- Run: func(cmd *cobra.Command, args []string) {
- err := RunGet(f, out, cmd, args)
- util.CheckErr(err)
- },
- ValidArgs: validArgs,
-}
-```
-
-Notice we put the "ValidArgs" on the "get" subcommand. Doing so will give results like
-
-```bash
-# kubectl get [tab][tab]
-node pod replicationcontroller service
-```
-
-### Plural form and shortcuts for nouns
-
-If your nouns have a number of aliases, you can define them alongside `ValidArgs` using `ArgAliases`:
-
-```go
-argAliases []string = { "pods", "nodes", "services", "svc", "replicationcontrollers", "rc" }
-
-cmd := &cobra.Command{
- ...
- ValidArgs: validArgs,
- ArgAliases: argAliases
-}
-```
-
-The aliases are not shown to the user on tab completion, but they are accepted as valid nouns by
-the completion algorithm if entered manually, e.g. in:
-
-```bash
-# kubectl get rc [tab][tab]
-backend frontend database
-```
-
-Note that without declaring `rc` as an alias, the completion algorithm would show the list of nouns
-in this example again instead of the replication controllers.
-
-### Dynamic completion of nouns
-
-In some cases it is not possible to provide a list of possible completions in advance. Instead, the list of completions must be determined at execution-time. Cobra provides two ways of defining such dynamic completion of nouns. Note that both these methods can be used along-side each other as long as they are not both used for the same command.
+## Bash legacy dynamic completions
-**Note**: *Custom Completions written in Go* will automatically work for other shell-completion scripts (e.g., Fish shell), while *Custom Completions written in Bash* will only work for Bash shell-completion. It is therefore recommended to use *Custom Completions written in Go*.
-
-#### 1. Custom completions of nouns written in Go
-
-In a similar fashion as for static completions, you can use the `ValidArgsFunction` field to provide a Go function that Cobra will execute when it needs the list of completion choices for the nouns of a command. Note that either `ValidArgs` or `ValidArgsFunction` can be used for a single cobra command, but not both.
-Simplified code from `helm status` looks like:
-
-```go
-cmd := &cobra.Command{
- Use: "status RELEASE_NAME",
- Short: "Display the status of the named release",
- Long: status_long,
- RunE: func(cmd *cobra.Command, args []string) {
- RunGet(args[0])
- },
- ValidArgsFunction: func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
- if len(args) != 0 {
- return nil, cobra.ShellCompDirectiveNoFileComp
- }
- return getReleasesFromCluster(toComplete), cobra.ShellCompDirectiveNoFileComp
- },
-}
-```
-Where `getReleasesFromCluster()` is a Go function that obtains the list of current Helm releases running on the Kubernetes cluster.
-Notice we put the `ValidArgsFunction` on the `status` subcommand. Let's assume the Helm releases on the cluster are: `harbor`, `notary`, `rook` and `thanos` then this dynamic completion will give results like
-
-```bash
-# helm status [tab][tab]
-harbor notary rook thanos
-```
-You may have noticed the use of `cobra.ShellCompDirective`. These directives are bit fields allowing to control some shell completion behaviors for your particular completion. You can combine them with the bit-or operator such as `cobra.ShellCompDirectiveNoSpace | cobra.ShellCompDirectiveNoFileComp`
-```go
-// Indicates an error occurred and completions should be ignored.
-ShellCompDirectiveError
-// Indicates that the shell should not add a space after the completion,
-// even if there is a single completion provided.
-ShellCompDirectiveNoSpace
-// Indicates that the shell should not provide file completion even when
-// no completion is provided.
-// This currently does not work for zsh or bash < 4
-ShellCompDirectiveNoFileComp
-// Indicates that the shell will perform its default behavior after completions
-// have been provided (this implies !ShellCompDirectiveNoSpace && !ShellCompDirectiveNoFileComp).
-ShellCompDirectiveDefault
-```
+For backwards-compatibility, Cobra still supports its legacy dynamic completion solution (described below). Unlike the `ValidArgsFunction` solution, the legacy solution will only work for Bash shell-completion and not for other shells. This legacy solution can be used along-side `ValidArgsFunction` and `RegisterFlagCompletionFunc()`, as long as both solutions are not used for the same command. This provides a path to gradually migrate from the legacy solution to the new solution.
-When using the `ValidArgsFunction`, Cobra will call your registered function after having parsed all flags and arguments provided in the command-line. You therefore don't need to do this parsing yourself. For example, when a user calls `helm status --namespace my-rook-ns [tab][tab]`, Cobra will call your registered `ValidArgsFunction` after having parsed the `--namespace` flag, as it would have done when calling the `RunE` function.
+The legacy solution allows you to inject bash functions into the bash completion script. Those bash functions are responsible for providing the completion choices for your own completions.
-##### Debugging
-
-Cobra achieves dynamic completions written in Go through the use of a hidden command called by the completion script. To debug your Go completion code, you can call this hidden command directly:
-```bash
-# helm __complete status har<ENTER>
-harbor
-:4
-Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
-```
-***Important:*** If the noun to complete is empty, you must pass an empty parameter to the `__complete` command:
-```bash
-# helm __complete status ""<ENTER>
-harbor
-notary
-rook
-thanos
-:4
-Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
-```
-Calling the `__complete` command directly allows you to run the Go debugger to troubleshoot your code. You can also add printouts to your code; Cobra provides the following functions to use for printouts in Go completion code:
-```go
-// Prints to the completion script debug file (if BASH_COMP_DEBUG_FILE
-// is set to a file path) and optionally prints to stderr.
-cobra.CompDebug(msg string, printToStdErr bool) {
-cobra.CompDebugln(msg string, printToStdErr bool)
-
-// Prints to the completion script debug file (if BASH_COMP_DEBUG_FILE
-// is set to a file path) and to stderr.
-cobra.CompError(msg string)
-cobra.CompErrorln(msg string)
-```
-***Important:*** You should **not** leave traces that print to stdout in your completion code as they will be interpreted as completion choices by the completion script. Instead, use the cobra-provided debugging traces functions mentioned above.
-
-#### 2. Custom completions of nouns written in Bash
-
-This method allows you to inject bash functions into the completion script. Those bash functions are responsible for providing the completion choices for your own completions.
-
-Some more actual code that works in kubernetes:
+Some code that works in kubernetes:
```bash
const (
@@ -253,93 +61,7 @@ Find more information at https://github.com/GoogleCloudPlatform/kubernetes.`,
The `BashCompletionFunction` option is really only valid/useful on the root command. Doing the above will cause `__kubectl_custom_func()` (`__<command-use>_custom_func()`) to be called when the built in processor was unable to find a solution. In the case of kubernetes a valid command might look something like `kubectl get pod [mypod]`. If you type `kubectl get pod [tab][tab]` the `__kubectl_customc_func()` will run because the cobra.Command only understood "kubectl" and "get." `__kubectl_custom_func()` will see that the cobra.Command is "kubectl_get" and will thus call another helper `__kubectl_get_resource()`. `__kubectl_get_resource` will look at the 'nouns' collected. In our example the only noun will be `pod`. So it will call `__kubectl_parse_get pod`. `__kubectl_parse_get` will actually call out to kubernetes and get any pods. It will then set `COMPREPLY` to valid pods!
-## Mark flags as required
-
-Most of the time completions will only show subcommands. But if a flag is required to make a subcommand work, you probably want it to show up when the user types [tab][tab]. Marking a flag as 'Required' is incredibly easy.
-
-```go
-cmd.MarkFlagRequired("pod")
-cmd.MarkFlagRequired("container")
-```
-
-and you'll get something like
-
-```bash
-# kubectl exec [tab][tab][tab]
--c --container= -p --pod=
-```
-
-# Specify valid filename extensions for flags that take a filename
-
-In this example we use --filename= and expect to get a json or yaml file as the argument. To make this easier we annotate the --filename flag with valid filename extensions.
-
-```go
- annotations := []string{"json", "yaml", "yml"}
- annotation := make(map[string][]string)
- annotation[cobra.BashCompFilenameExt] = annotations
-
- flag := &pflag.Flag{
- Name: "filename",
- Shorthand: "f",
- Usage: usage,
- Value: value,
- DefValue: value.String(),
- Annotations: annotation,
- }
- cmd.Flags().AddFlag(flag)
-```
-
-Now when you run a command with this filename flag you'll get something like
-
-```bash
-# kubectl create -f
-test/ example/ rpmbuild/
-hello.yml test.json
-```
-
-So while there are many other files in the CWD it only shows me subdirs and those with valid extensions.
-
-# Specify custom flag completion
-
-As for nouns, Cobra provides two ways of defining dynamic completion of flags. Note that both these methods can be used along-side each other as long as they are not both used for the same flag.
-
-**Note**: *Custom Completions written in Go* will automatically work for other shell-completion scripts (e.g., Fish shell), while *Custom Completions written in Bash* will only work for Bash shell-completion. It is therefore recommended to use *Custom Completions written in Go*.
-
-## 1. Custom completions of flags written in Go
-
-To provide a Go function that Cobra will execute when it needs the list of completion choices for a flag, you must register the function in the following manner:
-
-```go
-flagName := "output"
-cmd.RegisterFlagCompletionFunc(flagName, func(cmd *cobra.Command, args []string, toComplete string) ([]string, cobra.ShellCompDirective) {
- return []string{"json", "table", "yaml"}, cobra.ShellCompDirectiveDefault
-})
-```
-Notice that calling `RegisterFlagCompletionFunc()` is done through the `command` with which the flag is associated. In our example this dynamic completion will give results like so:
-
-```bash
-# helm status --output [tab][tab]
-json table yaml
-```
-
-### Debugging
-
-You can also easily debug your Go completion code for flags:
-```bash
-# helm __complete status --output ""
-json
-table
-yaml
-:4
-Completion ended with directive: ShellCompDirectiveNoFileComp # This is on stderr
-```
-***Important:*** You should **not** leave traces that print to stdout in your completion code as they will be interpreted as completion choices by the completion script. Instead, use the cobra-provided debugging traces functions mentioned in the above section.
-
-## 2. Custom completions of flags written in Bash
-
-Alternatively, you can use bash code for flag custom completion. Similar to the filename
-completion and filtering using `cobra.BashCompFilenameExt`, you can specify
-a custom flag completion bash function with `cobra.BashCompCustom`:
+Similarly, for flags:
```go
annotation := make(map[string][]string)
@@ -367,17 +89,3 @@ __kubectl_get_namespaces()
fi
}
```
-# Using bash aliases for commands
-
-You can also configure the `bash aliases` for the commands and they will also support completions.
-
-```bash
-alias aliasname=origcommand
-complete -o default -F __start_origcommand aliasname
-
-# and now when you run `aliasname` completion will make
-# suggestions as it did for `origcommand`.
-
-$) aliasname <tab><tab>
-completion firstcommand secondcommand
-```