diff options
Diffstat (limited to 'cmd/run.go')
| -rw-r--r-- | cmd/run.go | 443 |
1 files changed, 220 insertions, 223 deletions
@@ -1,223 +1,220 @@ -/*
- * run.go - Functions to setup and run Command Actions.
- *
- * Copyright 2017 Google Inc.
- * Author: Joe Richey (joerichey@google.com)
- *
- * 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 cmd
-
-import (
- "flag"
- "fmt"
- "io/ioutil"
- "log"
- "os"
-)
-
-var (
- // HelpAction is performed whenever a Command uses the HelpFlag.
- HelpAction Action = func(ctx *Context) error {
- ExecuteTemplate(os.Stdout, TemplateTitle, ctx)
- ExecuteTemplate(os.Stdout, TemplateUsage, ctx)
- return nil
- }
- // DefaultAction is preformed when a Command has no Action specified.
- DefaultAction = HelpAction
- // stopFlag indicates that everything after the flag is an argument, not
- // a command or flag.
- stopFlag = "--"
-)
-
-// TemplateTitle describes the format of a Command's one line title.
-var TemplateTitle = "{{.FullName}}{{if .Command.Title}} - {{.Command.Title}}{{end}}\n"
-
-// TemplateUsage describes the format of a Command's usage.
-var TemplateUsage = `{{with $lines := .Command.UsageLines}}
-Usage:
-{{- range $lines}}
- {{printf "%s %s" $.FullName . | WrapText 8 2 -}}
-{{end}}
-{{end -}}
-
-{{with $commands := .Command.SubCommands}}
-{{with $n := $.Command.MaxNameLength -}}
-{{with $fmt := printf "%%-%ds - %%s" $n -}}
-Commands:
-{{if le (add 8 $n 3 $.Command.MaxTitleLength) LineLength -}}
-
-{{range $commands -}}
-
-{{end -}}
-
-{{else -}}
-
-{{range $commands}}
-{{end -}}
-
-{{end}}{{end}}{{end}}
-{{end -}}
-
-
-{{- range $commands}}
- {{if not .Title -}}
- {{.Name -}}
- {{else if le (add 8 $n 3 (len .Title)) LineLength -}}
- {{printf $fmt .Name .Title -}}
- {{else -}}
- {{.Name}}
- {{WrapText 16 2 .Title -}}
- {{end -}}
-{{end}}{{end}}{{end}}
-{{end -}}
-
-{{with $arguments := .FullArguments}}
-Arguments:
-{{- range $arguments}}
- {{.}}
- {{WrapText 16 2 .Usage -}}
-{{end}}
-{{end -}}
-
-{{with $flags := .FullFlags}}
-Options:
-{{- range $flags}}
- {{.}}
- {{WrapText 16 2 .FullUsage -}}
-{{end}}
-{{end -}}
-
-{{with .ManPage}}
-For more information, see {{.}}.
-{{end -}}
-`
-
-// Divide the arguments into flag arguments (those starting with "-") and normal
-// arguments. If "--" appears in the list, it will classified as a normal
-// argument as well as all arguments following it. Also removes empty args.
-func sortArgs(args []string) (normalArgs, flagArgs []string) {
- var arg string
- for len(args) > 0 {
- arg, args = args[0], args[1:]
- if arg == "" {
- continue
- }
- if arg == stopFlag {
- normalArgs = append(normalArgs, arg)
- normalArgs = append(normalArgs, args...)
- return
- } else if arg[0] == '-' {
- flagArgs = append(flagArgs, arg)
- } else {
- normalArgs = append(normalArgs, arg)
- }
- }
- return
-}
-
-// Returns the name of the requested sub-command or empty string (if a
-// sub-command was not requested).
-func subCommandName(ctx *Context) string {
- // We must have actual arguments and subcommands to run a sub-command.
- if len(ctx.Command.SubCommands) == 0 || len(ctx.Args) == 0 {
- return ""
- }
- name := ctx.Args[0]
- if name == stopFlag {
- return ""
- }
- return name
-}
-
-// Returns the appropriate child context with a sub-command whose name matches
-// the provided name. If no sub-commands match the provied name, handle the
-// appropriate error and do not return.
-func getSubContext(ctx *Context, name string) *Context {
- for _, subCommand := range ctx.Command.SubCommands {
- if subCommand.Name == name {
- return &Context{
- Command: subCommand,
- Parent: ctx,
- Args: ctx.Args[1:],
- flagArgs: ctx.flagArgs,
- }
- }
- }
- ctx.processError(UsageError(fmt.Sprintf("unknown command %q", name)))
- return nil
-}
-
-// Configures the Output and log output io.Writers. Called before running
-// commands but after processing flags.
-func setupOutput() {
- if VerboseFlag.Value {
- log.SetOutput(os.Stdout)
- } else {
- log.SetOutput(ioutil.Discard)
- }
- if Output != nil {
- return
- }
- if QuietFlag.Value {
- Output = ioutil.Discard
- } else {
- Output = os.Stdout
- }
-}
-
-// Remove the stopFlag from the args if it is present. Args are modified
-// in-place and the correctly sized slice is returned.
-func setupArgs(args []string) []string {
- for i, arg := range args {
- if arg == stopFlag {
- return append(args[:i], args[i+1:]...)
- }
- }
- return args
-}
-
-// Return a command's action, the HelpAction, or DefaultAction.
-func getAction(cmd *Command) Action {
- if HelpFlag.Value {
- return HelpAction
- }
- if cmd.Action == nil {
- return DefaultAction
- }
- return cmd.Action
-}
-
-func (ctx *Context) run() {
- if name := subCommandName(ctx); name != "" {
- getSubContext(ctx, name).run()
- return
- }
-
- flagSet := flag.NewFlagSet("", flag.ContinueOnError)
- flagSet.SetOutput(ioutil.Discard)
- for _, flag := range ctx.FullFlags() {
- flag.Apply(flagSet)
- }
- if err := flagSet.Parse(ctx.flagArgs); err != nil {
- ctx.processError(err)
- return
- }
-
- setupOutput()
- ctx.Args = setupArgs(ctx.Args)
- action := getAction(ctx.Command)
-
- ctx.processError(action(ctx))
-}
+/* + * run.go - Functions to setup and run Command Actions. + * + * Copyright 2017 Google Inc. + * Author: Joe Richey (joerichey@google.com) + * + * 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 cmd + +import ( + "flag" + "fmt" + "io/ioutil" + "log" + "os" +) + +var ( + // HelpAction is performed whenever a Command uses the HelpFlag. + HelpAction Action = func(ctx *Context) error { + ExecuteTemplate(os.Stdout, TemplateTitle, ctx) + ExecuteTemplate(os.Stdout, TemplateUsage, ctx) + return nil + } + // DefaultAction is preformed when a Command has no Action specified. + DefaultAction = HelpAction + // stopFlag indicates that everything after the flag is an argument, not + // a command or flag. + stopFlag = "--" +) + +// TemplateTitle describes the format of a Command's one line title. +var TemplateTitle = "{{.FullName}}{{if .Command.Title}} - {{.Command.Title}}{{end}}\n" + +// TemplateUsage describes the format of a Command's usage. +var TemplateUsage = `{{with $lines := .Command.UsageLines}} +Usage: +{{- range $lines}} + {{printf "%s %s" $.FullName . | WrapText 8 2 -}} +{{end}} +{{end -}} + +{{with $commands := .Command.SubCommands}} +{{with $n := $.Command.MaxNameLength -}} +{{with $fmt := printf "%%-%ds - %%s" $n -}} +Commands: +{{- if le (add 8 $n 3 $.Command.MaxTitleLength) LineLength -}} + +{{range $commands -}} + {{if not .Title}} + {{.Name -}} + {{else}} + {{printf $fmt .Name .Title -}} + {{end -}} +{{end -}} + +{{else -}} + +{{range $commands -}} + {{if not .Title}} + {{.Name -}} + {{else}} + {{.Name}} + {{WrapText 16 2 .Title -}} + {{end -}} +{{end -}} + +{{end}}{{end}}{{end}} +{{end -}} + +{{with $arguments := .FullArguments}} +Arguments: +{{- range $arguments}} + {{.}} + {{WrapText 16 2 .Usage -}} +{{end}} +{{end -}} + +{{with $flags := .FullFlags}} +Options: +{{- range $flags}} + {{.}} + {{WrapText 16 2 .FullUsage -}} +{{end}} +{{end -}} + +{{with .ManPage}} +For more information, see {{.}}. +{{end -}} +` + +// Divide the arguments into flag arguments (those starting with "-") and normal +// arguments. If "--" appears in the list, it will classified as a normal +// argument as well as all arguments following it. Also removes empty args. +func sortArgs(args []string) (normalArgs, flagArgs []string) { + var arg string + for len(args) > 0 { + arg, args = args[0], args[1:] + if arg == "" { + continue + } + if arg == stopFlag { + normalArgs = append(normalArgs, arg) + normalArgs = append(normalArgs, args...) + return + } else if arg[0] == '-' { + flagArgs = append(flagArgs, arg) + } else { + normalArgs = append(normalArgs, arg) + } + } + return +} + +// Returns the name of the requested sub-command or empty string (if a +// sub-command was not requested). +func subCommandName(ctx *Context) string { + // We must have actual arguments and subcommands to run a sub-command. + if len(ctx.Command.SubCommands) == 0 || len(ctx.Args) == 0 { + return "" + } + name := ctx.Args[0] + if name == stopFlag { + return "" + } + return name +} + +// Returns the appropriate child context with a sub-command whose name matches +// the provided name. If no sub-commands match the provied name, handle the +// appropriate error and do not return. +func getSubContext(ctx *Context, name string) *Context { + for _, subCommand := range ctx.Command.SubCommands { + if subCommand.Name == name { + return &Context{ + Command: subCommand, + Parent: ctx, + Args: ctx.Args[1:], + flagArgs: ctx.flagArgs, + } + } + } + ctx.processError(UsageError(fmt.Sprintf("unknown command %q", name))) + return nil +} + +// Configures the Output and log output io.Writers. Called before running +// commands but after processing flags. +func setupOutput() { + if VerboseFlag.Value { + log.SetOutput(os.Stdout) + } else { + log.SetOutput(ioutil.Discard) + } + if Output != nil { + return + } + if QuietFlag.Value { + Output = ioutil.Discard + } else { + Output = os.Stdout + } +} + +// Remove the stopFlag from the args if it is present. Args are modified +// in-place and the correctly sized slice is returned. +func setupArgs(args []string) []string { + for i, arg := range args { + if arg == stopFlag { + return append(args[:i], args[i+1:]...) + } + } + return args +} + +// Return a command's action, the HelpAction, or DefaultAction. +func getAction(cmd *Command) Action { + if HelpFlag.Value { + return HelpAction + } + if cmd.Action == nil { + return DefaultAction + } + return cmd.Action +} + +func (ctx *Context) run() { + if name := subCommandName(ctx); name != "" { + getSubContext(ctx, name).run() + return + } + + flagSet := flag.NewFlagSet("", flag.ContinueOnError) + flagSet.SetOutput(ioutil.Discard) + for _, flag := range ctx.FullFlags() { + flag.Apply(flagSet) + } + if err := flagSet.Parse(ctx.flagArgs); err != nil { + ctx.processError(err) + return + } + + setupOutput() + ctx.Args = setupArgs(ctx.Args) + action := getAction(ctx.Command) + + ctx.processError(action(ctx)) +} |