Merge branch 'master' into backport-json-support

CHANGELOG.md

@@ -4,6 +4,49 @@
 
 ## [Unreleased]
 
+## 1.20.0 - 2017-08-10
+
+### Fixed
+
+* `HandleExitCoder` is now correctly iterates over all errors in
+  a `MultiError`. The exit code is the exit code of the last error or `1` if
+  there are no `ExitCoder`s in the `MultiError`.
+* Fixed YAML file loading on Windows (previously would fail validate the file path)
+* Subcommand `Usage`, `Description`, `ArgsUsage`, `OnUsageError` correctly
+  propogated
+* `ErrWriter` is now passed downwards through command structure to avoid the
+  need to redefine it
+* Pass `Command` context into `OnUsageError` rather than parent context so that
+  all fields are avaiable
+* Errors occuring in `Before` funcs are no longer double printed
+* Use `UsageText` in the help templates for commands and subcommands if
+  defined; otherwise build the usage as before (was previously ignoring this
+  field)
+* `IsSet` and `GlobalIsSet` now correctly return whether a flag is set if
+  a program calls `Set` or `GlobalSet` directly after flag parsing (would
+  previously only return `true` if the flag was set during parsing)
+
+### Changed
+
+* No longer exit the program on command/subcommand error if the error raised is
+  not an `OsExiter`. This exiting behavior was introduced in 1.19.0, but was
+  determined to be a regression in functionality. See [the
+  PR](https://github.com/urfave/cli/pull/595) for discussion.
+
+### Added
+
+* `CommandsByName` type was added to make it easy to sort `Command`s by name,
+  alphabetically
+* `altsrc` now handles loading of string and int arrays from TOML
+* Support for definition of custom help templates for `App` via
+  `CustomAppHelpTemplate`
+* Support for arbitrary key/value fields on `App` to be used with
+  `CustomAppHelpTemplate` via `ExtraInfo`
+* `HelpFlag`, `VersionFlag`, and `BashCompletionFlag` changed to explictly be
+  `cli.Flag`s allowing for the use of custom flags satisfying the `cli.Flag`
+  interface to be used.
+
+
 ## [1.19.1] - 2016-11-21
 
 ### Fixed

CODE_OF_CONDUCT.md

@@ -0,0 +1,74 @@
+# Contributor Covenant Code of Conduct
+
+## Our Pledge
+
+In the interest of fostering an open and welcoming environment, we as
+contributors and maintainers pledge to making participation in our project and
+our community a harassment-free experience for everyone, regardless of age, body
+size, disability, ethnicity, gender identity and expression, level of experience,
+education, socio-economic status, nationality, personal appearance, race,
+religion, or sexual identity and orientation.
+
+## Our Standards
+
+Examples of behavior that contributes to creating a positive environment
+include:
+
+* Using welcoming and inclusive language
+* Being respectful of differing viewpoints and experiences
+* Gracefully accepting constructive criticism
+* Focusing on what is best for the community
+* Showing empathy towards other community members
+
+Examples of unacceptable behavior by participants include:
+
+* The use of sexualized language or imagery and unwelcome sexual attention or
+  advances
+* Trolling, insulting/derogatory comments, and personal or political attacks
+* Public or private harassment
+* Publishing others' private information, such as a physical or electronic
+  address, without explicit permission
+* Other conduct which could reasonably be considered inappropriate in a
+  professional setting
+
+## Our Responsibilities
+
+Project maintainers are responsible for clarifying the standards of acceptable
+behavior and are expected to take appropriate and fair corrective action in
+response to any instances of unacceptable behavior.
+
+Project maintainers have the right and responsibility to remove, edit, or
+reject comments, commits, code, wiki edits, issues, and other contributions
+that are not aligned to this Code of Conduct, or to ban temporarily or
+permanently any contributor for other behaviors that they deem inappropriate,
+threatening, offensive, or harmful.
+
+## Scope
+
+This Code of Conduct applies both within project spaces and in public spaces
+when an individual is representing the project or its community. Examples of
+representing a project or community include using an official project e-mail
+address, posting via an official social media account, or acting as an appointed
+representative at an online or offline event. Representation of a project may be
+further defined and clarified by project maintainers.
+
+## Enforcement
+
+Instances of abusive, harassing, or otherwise unacceptable behavior may be
+reported by contacting Dan Buch at dan@meatballhat.com. All complaints will be
+reviewed and investigated and will result in a response that is deemed necessary
+and appropriate to the circumstances. The project team is obligated to maintain
+confidentiality with regard to the reporter of an incident.  Further details of
+specific enforcement policies may be posted separately.
+
+Project maintainers who do not follow or enforce the Code of Conduct in good
+faith may face temporary or permanent repercussions as determined by other
+members of the project's leadership.
+
+## Attribution
+
+This Code of Conduct is adapted from the [Contributor Covenant][homepage], version 1.4,
+available at https://www.contributor-covenant.org/version/1/4/code-of-conduct.html
+
+[homepage]: https://www.contributor-covenant.org
+

CONTRIBUTING.md

@@ -0,0 +1,19 @@
+## Contributing
+
+**NOTE**: the primary maintainer(s) may be found in
+[./MAINTAINERS.md](./MAINTAINERS.md).
+
+Feel free to put up a pull request to fix a bug or maybe add a feature. I will
+give it a code review and make sure that it does not break backwards
+compatibility. If I or any other collaborators agree that it is in line with
+the vision of the project, we will work with you to get the code into
+a mergeable state and merge it into the master branch.
+
+If you have contributed something significant to the project, we will most
+likely add you as a collaborator. As a collaborator you are given the ability
+to merge others pull requests. It is very important that new code does not
+break existing code, so be careful about what code you do choose to merge.
+
+If you feel like you have contributed to the project but have not yet been added
+as a collaborator, we probably forgot to add you :sweat_smile:.  Please open an
+issue!

MAINTAINERS.md

@@ -0,0 +1 @@
+- @meatballhat

README.md

@@ -9,9 +9,9 @@ cli
 [![top level coverage](https://gocover.io/_badge/github.com/urfave/cli?0 "top level coverage")](http://gocover.io/github.com/urfave/cli) /
 [![altsrc coverage](https://gocover.io/_badge/github.com/urfave/cli/altsrc?0 "altsrc coverage")](http://gocover.io/github.com/urfave/cli/altsrc)
 
-**Notice:** This is the library formerly known as
-`github.com/codegangsta/cli` -- Github will automatically redirect requests
-to this repository, but we recommend updating your references for clarity.
+This is the library formerly known as `github.com/codegangsta/cli` -- Github
+will automatically redirect requests to this repository, but we recommend
+updating your references for clarity.
 
 cli is a simple, fast, and fun package for building command line apps in Go. The
 goal is to enable developers to write fast and distributable command line
@@ -32,7 +32,9 @@ applications in an expressive way.
     + [Alternate Names](#alternate-names)
     + [Ordering](#ordering)
     + [Values from the Environment](#values-from-the-environment)
+    + [Values from files](#values-from-files)
     + [Values from alternate input sources (YAML, TOML, and others)](#values-from-alternate-input-sources-yaml-toml-and-others)
+    + [Precedence](#precedence)
   * [Subcommands](#subcommands)
   * [Subcommands categories](#subcommands-categories)
   * [Exit code](#exit-code)
@@ -45,6 +47,7 @@ applications in an expressive way.
   * [Version Flag](#version-flag)
     + [Customization](#customization-2)
     + [Full API Example](#full-api-example)
+  * [Combining short Bool options](#combining-short-bool-options)
 - [Contribution Guidelines](#contribution-guidelines)
 
 <!-- tocstop -->
@@ -138,13 +141,17 @@ discovery. So a cli app can be as little as one line of code in `main()`.
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
 )
 
 func main() {
-  cli.NewApp().Run(os.Args)
+  err := cli.NewApp().Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -159,6 +166,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -173,7 +181,10 @@ func main() {
     return nil
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -197,6 +208,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -211,7 +223,10 @@ func main() {
     return nil
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -260,6 +275,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -273,7 +289,10 @@ func main() {
     return nil
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -289,6 +308,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -318,7 +338,10 @@ func main() {
     return nil
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -332,6 +355,7 @@ scanned.
 package main
 
 import (
+  "log"
   "os"
   "fmt"
 
@@ -365,7 +389,10 @@ func main() {
     return nil
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -386,6 +413,7 @@ For example this:
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -401,7 +429,10 @@ func main() {
     },
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -427,6 +458,7 @@ list for the `Name`. e.g.
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -443,7 +475,10 @@ func main() {
     },
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -467,6 +502,7 @@ For example this:
 package main
 
 import (
+  "log"
   "os"
   "sort"
 
@@ -510,7 +546,10 @@ func main() {
   sort.Sort(cli.FlagsByName(app.Flags))
   sort.Sort(cli.CommandsByName(app.Commands))
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -533,6 +572,7 @@ You can also have the default value set from the environment via `EnvVar`.  e.g.
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -550,7 +590,10 @@ func main() {
     },
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -565,6 +608,7 @@ environment variable that resolves is used as the default.
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -582,10 +626,52 @@ func main() {
     },
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
+#### Values from files
+
+You can also have the default value set from file via `FilePath`.  e.g.
+
+<!-- {
+  "args": ["&#45;&#45;help"],
+  "output": "password for the mysql database"
+} -->
+``` go
+package main
+
+import (
+  "log"
+  "os"
+
+  "github.com/urfave/cli"
+)
+
+func main() {
+  app := cli.NewApp()
+
+  app.Flags = []cli.Flag {
+    cli.StringFlag{
+      Name: "password, p",
+      Usage: "password for the mysql database",
+      FilePath: "/etc/mysql/password",
+    },
+  }
+
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
+}
+```
+
+Note that default values set from file (e.g. `FilePath`) take precedence over
+default values set from the enviornment (e.g. `EnvVar`).
+
 #### Values from alternate input sources (YAML, TOML, and others)
 
 There is a separate package altsrc that adds support for getting flag values
@@ -630,6 +716,7 @@ package notmain
 
 import (
   "fmt"
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -652,10 +739,22 @@ func main() {
   app.Before = altsrc.InitInputSourceWithContext(flags, altsrc.NewYamlSourceFromFlagFunc("load"))
   app.Flags = flags
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
+#### Precedence
+
+The precedence for flag value sources is as follows (highest to lowest):
+
+0. Command line flag value from user
+0. Environment variable (if specified)
+0. Configuration file (if specified)
+0. Default defined on the flag
+
 ### Subcommands
 
 Subcommands can be defined for a more git-like command line app.
@@ -669,6 +768,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -721,7 +821,10 @@ func main() {
     },
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -737,6 +840,7 @@ E.g.
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -751,15 +855,18 @@ func main() {
     },
     {
       Name:     "add",
-      Category: "template",
+      Category: "Template actions",
     },
     {
       Name:     "remove",
-      Category: "template",
+      Category: "Template actions",
     },
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -785,6 +892,7 @@ may be set by returning a non-nil error that fulfills `cli.ExitCoder`, *or* a
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -805,7 +913,10 @@ func main() {
     return nil
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -825,6 +936,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -856,7 +968,10 @@ func main() {
     },
   }
 
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -896,6 +1011,7 @@ The default bash completion flag (`--generate-bash-completion`) is defined as
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -914,7 +1030,10 @@ func main() {
       Name: "wat",
     },
   }
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -940,6 +1059,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "io"
   "os"
 
@@ -983,7 +1103,10 @@ VERSION:
     fmt.Println("Ha HA.  I pwnd the help!!1")
   }
 
-  cli.NewApp().Run(os.Args)
+  err := cli.NewApp().Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -998,6 +1121,7 @@ setting `cli.HelpFlag`, e.g.:
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -1010,7 +1134,10 @@ func main() {
     EnvVar: "SHOW_HALP,HALPPLZ",
   }
 
-  cli.NewApp().Run(os.Args)
+  err := cli.NewApp().Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -1033,6 +1160,7 @@ setting `cli.VersionFlag`, e.g.:
 package main
 
 import (
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -1047,7 +1175,10 @@ func main() {
   app := cli.NewApp()
   app.Name = "partay"
   app.Version = "19.99.0"
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -1062,6 +1193,7 @@ package main
 
 import (
   "fmt"
+  "log"
   "os"
 
   "github.com/urfave/cli"
@@ -1079,7 +1211,10 @@ func main() {
   app := cli.NewApp()
   app.Name = "partay"
   app.Version = "19.99.0"
-  app.Run(os.Args)
+  err := app.Run(os.Args)
+  if err != nil {
+    log.Fatal(err)
+  }
 }
 ```
 
@@ -1341,7 +1476,7 @@ func main() {
     ec := cli.NewExitError("ohwell", 86)
     fmt.Fprintf(c.App.Writer, "%d", ec.ExitCode())
     fmt.Printf("made it!\n")
-    return ec
+    return nil
   }
 
   if os.Getenv("HEXY") != "" {
@@ -1355,7 +1490,9 @@ func main() {
     "whatever-values": 19.99,
   }
 
-  app.Run(os.Args)
+
+  // ignore error so we don't exit non-zero and break gfmrun README example tests
+  _ = app.Run(os.Args)
 }
 
 func wopAction(c *cli.Context) error {
@@ -1364,18 +1501,26 @@ func wopAction(c *cli.Context) error {
 }
 ```
 
-## Contribution Guidelines
+### Combining short Bool options
 
-Feel free to put up a pull request to fix a bug or maybe add a feature. I will
-give it a code review and make sure that it does not break backwards
-compatibility. If I or any other collaborators agree that it is in line with
-the vision of the project, we will work with you to get the code into
-a mergeable state and merge it into the master branch.
+Traditional use of boolean options using their shortnames look like this:
+```
+# cmd foobar -s -o
+```
 
-If you have contributed something significant to the project, we will most
-likely add you as a collaborator. As a collaborator you are given the ability
-to merge others pull requests. It is very important that new code does not
-break existing code, so be careful about what code you do choose to merge.
+Suppose you want users to be able to combine your bool options with their shortname.  This
+can be done using the **UseShortOptionHandling** bool in your commands.  Suppose your program
+has a two bool flags such as *serve* and *option* with the short options of *-o* and
+*-s* respectively. With **UseShortOptionHandling** set to *true*, a user can use a syntax
+like:
+```
+# cmd foobar -so
+```
+
+If you enable the **UseShortOptionHandling*, then you must not use any flags that have a single
+leading *-* or this will result in failures.  For example, **-option** can no longer be used.  Flags
+with two leading dashes (such as **--options**) are still valid.
+
+## Contribution Guidelines
 
-If you feel like you have contributed to the project but have not yet been
-added as a collaborator, we probably forgot to add you, please open an issue.
+See [./CONTRIBUTING.md](./CONTRIBUTING.md)

altsrc/map_input_source.go

@@ -22,15 +22,15 @@ func nestedVal(name string, tree map[interface{}]interface{}) (interface{}, bool
 	if sections := strings.Split(name, "."); len(sections) > 1 {
 		node := tree
 		for _, section := range sections[:len(sections)-1] {
-			if child, ok := node[section]; !ok {
+			child, ok := node[section]
+			if !ok {
 				return nil, false
-			} else {
-				if ctype, ok := child.(map[interface{}]interface{}); !ok {
-					return nil, false
-				} else {
-					node = ctype
-				}
 			}
+			ctype, ok := child.(map[interface{}]interface{})
+			if !ok {
+				return nil, false
+			}
+			node = ctype
 		}
 		if val, ok := node[sections[len(sections)-1]]; ok {
 			return val, true

altsrc/toml_file_loader.go

@@ -66,9 +66,9 @@ func unmarshalMap(i interface{}) (ret map[interface{}]interface{}, err error) {
 	return ret, nil
 }
 
-func (self *tomlMap) UnmarshalTOML(i interface{}) error {
+func (tm *tomlMap) UnmarshalTOML(i interface{}) error {
 	if tmp, err := unmarshalMap(i); err == nil {
-		self.Map = tmp
+		tm.Map = tmp
 	} else {
 		return err
 	}

altsrc/yaml_file_loader.go

@@ -86,7 +86,7 @@ func loadDataFrom(filePath string) ([]byte, error) {
 			return nil, fmt.Errorf("Cannot read from file: '%s' because it does not exist.", filePath)
 		}
 		return ioutil.ReadFile(filePath)
-	} else {
-		return nil, fmt.Errorf("unable to determine how to load from path %s", filePath)
 	}
+
+	return nil, fmt.Errorf("unable to determine how to load from path %s", filePath)
 }

app.go

@@ -83,6 +83,9 @@ type App struct {
 	Writer io.Writer
 	// ErrWriter writes error output
 	ErrWriter io.Writer
+	// Execute this function to handle ExitErrors. If not provided, HandleExitCoder is provided to
+	// function as a default, so this is optional.
+	ExitErrHandler ExitErrHandlerFunc
 	// Other custom info
 	Metadata map[string]interface{}
 	// Carries a function which returns app specific info.
@@ -207,7 +210,7 @@ func (a *App) Run(arguments []string) (err error) {
 	if err != nil {
 		if a.OnUsageError != nil {
 			err := a.OnUsageError(context, err, false)
-			HandleExitCoder(err)
+			a.handleExitCoder(context, err)
 			return err
 		}
 		fmt.Fprintf(a.Writer, "%s %s\n\n", "Incorrect Usage.", err.Error())
@@ -240,8 +243,9 @@ func (a *App) Run(arguments []string) (err error) {
 	if a.Before != nil {
 		beforeErr := a.Before(context)
 		if beforeErr != nil {
+			fmt.Fprintf(a.Writer, "%v\n\n", beforeErr)
 			ShowAppHelp(context)
-			HandleExitCoder(beforeErr)
+			a.handleExitCoder(context, beforeErr)
 			err = beforeErr
 			return err
 		}
@@ -263,7 +267,7 @@ func (a *App) Run(arguments []string) (err error) {
 	// Run default Action
 	err = HandleAction(a.Action, context)
 
-	HandleExitCoder(err)
+	a.handleExitCoder(context, err)
 	return err
 }
 
@@ -330,7 +334,7 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 	if err != nil {
 		if a.OnUsageError != nil {
 			err = a.OnUsageError(context, err, true)
-			HandleExitCoder(err)
+			a.handleExitCoder(context, err)
 			return err
 		}
 		fmt.Fprintf(a.Writer, "%s %s\n\n", "Incorrect Usage.", err.Error())
@@ -352,7 +356,7 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 		defer func() {
 			afterErr := a.After(context)
 			if afterErr != nil {
-				HandleExitCoder(err)
+				a.handleExitCoder(context, err)
 				if err != nil {
 					err = NewMultiError(err, afterErr)
 				} else {
@@ -365,7 +369,7 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 	if a.Before != nil {
 		beforeErr := a.Before(context)
 		if beforeErr != nil {
-			HandleExitCoder(beforeErr)
+			a.handleExitCoder(context, beforeErr)
 			err = beforeErr
 			return err
 		}
@@ -383,7 +387,7 @@ func (a *App) RunAsSubcommand(ctx *Context) (err error) {
 	// Run default Action
 	err = HandleAction(a.Action, context)
 
-	HandleExitCoder(err)
+	a.handleExitCoder(context, err)
 	return err
 }
 
@@ -449,7 +453,6 @@ func (a *App) hasFlag(flag Flag) bool {
 }
 
 func (a *App) errWriter() io.Writer {
-
 	// When the app ErrWriter is nil use the package level one.
 	if a.ErrWriter == nil {
 		return ErrWriter
@@ -464,6 +467,14 @@ func (a *App) appendFlag(flag Flag) {
 	}
 }
 
+func (a *App) handleExitCoder(context *Context, err error) {
+	if a.ExitErrHandler != nil {
+		a.ExitErrHandler(context, err)
+	} else {
+		HandleExitCoder(err)
+	}
+}
+
 // Author represents someone who has contributed to a cli project.
 type Author struct {
 	Name  string // The Authors name
@@ -491,7 +502,7 @@ func HandleAction(action interface{}, context *Context) (err error) {
 	} else if a, ok := action.(func(*Context)); ok { // deprecated function signature
 		a(context)
 		return nil
-	} else {
-		return errInvalidActionType
 	}
+
+	return errInvalidActionType
 }

app_test.go

@@ -258,6 +258,44 @@ func ExampleApp_Run_bashComplete() {
 	// h
 }
 
+func ExampleApp_Run_zshComplete() {
+	// set args for examples sake
+	os.Args = []string{"greet", "--generate-bash-completion"}
+	os.Setenv("_CLI_ZSH_AUTOCOMPLETE_HACK", "1")
+
+	app := NewApp()
+	app.Name = "greet"
+	app.EnableBashCompletion = true
+	app.Commands = []Command{
+		{
+			Name:        "describeit",
+			Aliases:     []string{"d"},
+			Usage:       "use it to see a description",
+			Description: "This is how we describe describeit the function",
+			Action: func(c *Context) error {
+				fmt.Printf("i like to describe things")
+				return nil
+			},
+		}, {
+			Name:        "next",
+			Usage:       "next example",
+			Description: "more stuff to see when generating bash completion",
+			Action: func(c *Context) error {
+				fmt.Printf("the next example")
+				return nil
+			},
+		},
+	}
+
+	app.Run(os.Args)
+	// Output:
+	// describeit:use it to see a description
+	// d:use it to see a description
+	// next:next example
+	// help:Shows a list of commands or help for one command
+	// h:Shows a list of commands or help for one command
+}
+
 func TestApp_Run(t *testing.T) {
 	s := ""
 
@@ -329,6 +367,39 @@ func TestApp_CommandWithArgBeforeFlags(t *testing.T) {
 	expect(t, firstArg, "my-arg")
 }
 
+func TestApp_CommandWithArgBeforeBoolFlags(t *testing.T) {
+	var parsedOption, parsedSecondOption, firstArg string
+	var parsedBool, parsedSecondBool bool
+
+	app := NewApp()
+	command := Command{
+		Name: "cmd",
+		Flags: []Flag{
+			StringFlag{Name: "option", Value: "", Usage: "some option"},
+			StringFlag{Name: "secondOption", Value: "", Usage: "another option"},
+			BoolFlag{Name: "boolflag", Usage: "some bool"},
+			BoolFlag{Name: "b", Usage: "another bool"},
+		},
+		Action: func(c *Context) error {
+			parsedOption = c.String("option")
+			parsedSecondOption = c.String("secondOption")
+			parsedBool = c.Bool("boolflag")
+			parsedSecondBool = c.Bool("b")
+			firstArg = c.Args().First()
+			return nil
+		},
+	}
+	app.Commands = []Command{command}
+
+	app.Run([]string{"", "cmd", "my-arg", "--boolflag", "--option", "my-option", "-b", "--secondOption", "fancy-option"})
+
+	expect(t, parsedOption, "my-option")
+	expect(t, parsedSecondOption, "fancy-option")
+	expect(t, parsedBool, true)
+	expect(t, parsedSecondBool, true)
+	expect(t, firstArg, "my-arg")
+}
+
 func TestApp_RunAsSubcommandParseFlags(t *testing.T) {
 	var context *Context
 
@@ -497,7 +568,6 @@ func TestApp_Float64Flag(t *testing.T) {
 }
 
 func TestApp_ParseSliceFlags(t *testing.T) {
-	var parsedOption, firstArg string
 	var parsedIntSlice []int
 	var parsedStringSlice []string
 
@@ -511,8 +581,6 @@ func TestApp_ParseSliceFlags(t *testing.T) {
 		Action: func(c *Context) error {
 			parsedIntSlice = c.IntSlice("p")
 			parsedStringSlice = c.StringSlice("ip")
-			parsedOption = c.String("option")
-			firstArg = c.Args().First()
 			return nil
 		},
 	}
@@ -1661,6 +1729,42 @@ func TestHandleAction_WithInvalidFuncReturnSignature(t *testing.T) {
 	}
 }
 
+func TestHandleExitCoder_Default(t *testing.T) {
+	app := NewApp()
+	fs, err := flagSet(app.Name, app.Flags)
+	if err != nil {
+		t.Errorf("error creating FlagSet: %s", err)
+	}
+
+	ctx := NewContext(app, fs, nil)
+	app.handleExitCoder(ctx, NewExitError("Default Behavior Error", 42))
+
+	output := fakeErrWriter.String()
+	if !strings.Contains(output, "Default") {
+		t.Fatalf("Expected Default Behavior from Error Handler but got: %s", output)
+	}
+}
+
+func TestHandleExitCoder_Custom(t *testing.T) {
+	app := NewApp()
+	fs, err := flagSet(app.Name, app.Flags)
+	if err != nil {
+		t.Errorf("error creating FlagSet: %s", err)
+	}
+
+	app.ExitErrHandler = func(_ *Context, _ error) {
+		fmt.Fprintln(ErrWriter, "I'm a Custom error handler, I print what I want!")
+	}
+
+	ctx := NewContext(app, fs, nil)
+	app.handleExitCoder(ctx, NewExitError("Default Behavior Error", 42))
+
+	output := fakeErrWriter.String()
+	if !strings.Contains(output, "Custom") {
+		t.Fatalf("Expected Custom Behavior from Error Handler but got: %s", output)
+	}
+}
+
 func TestHandleAction_WithUnknownPanic(t *testing.T) {
 	defer func() { refute(t, recover(), nil) }()
 

autocomplete/zsh_autocomplete

@@ -1,5 +1,11 @@
-autoload -U compinit && compinit
-autoload -U bashcompinit && bashcompinit
+_cli_zsh_autocomplete() {
 
-script_dir=$(dirname $0)
-source ${script_dir}/bash_autocomplete
+  local -a opts
+  opts=("${(@f)$(_CLI_ZSH_AUTOCOMPLETE_HACK=1 ${words[@]:0:#words[@]-1} --generate-bash-completion)}")
+
+  _describe 'values' opts
+
+  return
+}
+
+compdef _cli_zsh_autocomplete $PROG

category.go

@@ -10,7 +10,7 @@ type CommandCategory struct {
 }
 
 func (c CommandCategories) Less(i, j int) bool {
-	return c[i].Name < c[j].Name
+	return lexicographicLess(c[i].Name, c[j].Name)
 }
 
 func (c CommandCategories) Len() int {

command.go

@@ -1,6 +1,7 @@
 package cli
 
 import (
+	"flag"
 	"fmt"
 	"io/ioutil"
 	"sort"
@@ -55,6 +56,10 @@ type Command struct {
 	HideHelp bool
 	// Boolean to hide this command from help or completion
 	Hidden bool
+	// Boolean to enable short-option handling so user can combine several
+	// single-character bool arguements into one
+	// i.e. foobar -o -v -> foobar -ov
+	UseShortOptionHandling bool
 
 	// Full name of command for help, defaults to full command name, including parent commands.
 	HelpName        string
@@ -73,7 +78,7 @@ func (c CommandsByName) Len() int {
 }
 
 func (c CommandsByName) Less(i, j int) bool {
-	return c[i].Name < c[j].Name
+	return lexicographicLess(c[i].Name, c[j].Name)
 }
 
 func (c CommandsByName) Swap(i, j int) {
@@ -106,57 +111,7 @@ func (c Command) Run(ctx *Context) (err error) {
 		)
 	}
 
-	set, err := flagSet(c.Name, c.Flags)
-	if err != nil {
-		return err
-	}
-	set.SetOutput(ioutil.Discard)
-
-	if c.SkipFlagParsing {
-		err = set.Parse(append([]string{"--"}, ctx.Args().Tail()...))
-	} else if !c.SkipArgReorder {
-		firstFlagIndex := -1
-		terminatorIndex := -1
-		for index, arg := range ctx.Args() {
-			if arg == "--" {
-				terminatorIndex = index
-				break
-			} else if arg == "-" {
-				// Do nothing. A dash alone is not really a flag.
-				continue
-			} else if strings.HasPrefix(arg, "-") && firstFlagIndex == -1 {
-				firstFlagIndex = index
-			}
-		}
-
-		if firstFlagIndex > -1 {
-			args := ctx.Args()
-			regularArgs := make([]string, len(args[1:firstFlagIndex]))
-			copy(regularArgs, args[1:firstFlagIndex])
-
-			var flagArgs []string
-			if terminatorIndex > -1 {
-				flagArgs = args[firstFlagIndex:terminatorIndex]
-				regularArgs = append(regularArgs, args[terminatorIndex:]...)
-			} else {
-				flagArgs = args[firstFlagIndex:]
-			}
-
-			err = set.Parse(append(flagArgs, regularArgs...))
-		} else {
-			err = set.Parse(ctx.Args().Tail())
-		}
-	} else {
-		err = set.Parse(ctx.Args().Tail())
-	}
-
-	nerr := normalizeFlags(c.Flags, set)
-	if nerr != nil {
-		fmt.Fprintln(ctx.App.Writer, nerr)
-		fmt.Fprintln(ctx.App.Writer)
-		ShowCommandHelp(ctx, c.Name)
-		return nerr
-	}
+	set, err := c.parseFlags(ctx.Args().Tail())
 
 	context := NewContext(ctx.App, set, ctx)
 	context.Command = c
@@ -167,7 +122,7 @@ func (c Command) Run(ctx *Context) (err error) {
 	if err != nil {
 		if c.OnUsageError != nil {
 			err := c.OnUsageError(context, err, false)
-			HandleExitCoder(err)
+			context.App.handleExitCoder(context, err)
 			return err
 		}
 		fmt.Fprintln(context.App.Writer, "Incorrect Usage:", err.Error())
@@ -184,7 +139,7 @@ func (c Command) Run(ctx *Context) (err error) {
 		defer func() {
 			afterErr := c.After(context)
 			if afterErr != nil {
-				HandleExitCoder(err)
+				context.App.handleExitCoder(context, err)
 				if err != nil {
 					err = NewMultiError(err, afterErr)
 				} else {
@@ -198,7 +153,7 @@ func (c Command) Run(ctx *Context) (err error) {
 		err = c.Before(context)
 		if err != nil {
 			ShowCommandHelp(context, c.Name)
-			HandleExitCoder(err)
+			context.App.handleExitCoder(context, err)
 			return err
 		}
 	}
@@ -210,11 +165,88 @@ func (c Command) Run(ctx *Context) (err error) {
 	err = HandleAction(c.Action, context)
 
 	if err != nil {
-		HandleExitCoder(err)
+		context.App.handleExitCoder(context, err)
 	}
 	return err
 }
 
+func (c *Command) parseFlags(args Args) (*flag.FlagSet, error) {
+	set, err := flagSet(c.Name, c.Flags)
+	if err != nil {
+		return nil, err
+	}
+	set.SetOutput(ioutil.Discard)
+
+	if c.SkipFlagParsing {
+		return set, set.Parse(append([]string{"--"}, args...))
+	}
+
+	if c.UseShortOptionHandling {
+		args = translateShortOptions(args)
+	}
+
+	if !c.SkipArgReorder {
+		args = reorderArgs(args)
+	}
+
+	err = set.Parse(args)
+	if err != nil {
+		return nil, err
+	}
+
+	err = normalizeFlags(c.Flags, set)
+	if err != nil {
+		return nil, err
+	}
+
+	return set, nil
+}
+
+// reorderArgs moves all flags before arguments as this is what flag expects
+func reorderArgs(args []string) []string {
+	var nonflags, flags []string
+
+	readFlagValue := false
+	for i, arg := range args {
+		if arg == "--" {
+			nonflags = append(nonflags, args[i:]...)
+			break
+		}
+
+		if readFlagValue && !strings.HasPrefix(arg, "-") && !strings.HasPrefix(arg, "--") {
+			readFlagValue = false
+			flags = append(flags, arg)
+			continue
+		}
+		readFlagValue = false
+
+		if arg != "-" && strings.HasPrefix(arg, "-") {
+			flags = append(flags, arg)
+
+			readFlagValue = !strings.Contains(arg, "=")
+		} else {
+			nonflags = append(nonflags, arg)
+		}
+	}
+
+	return append(flags, nonflags...)
+}
+
+func translateShortOptions(flagArgs Args) []string {
+	// separate combined flags
+	var flagArgsSeparated []string
+	for _, flagArg := range flagArgs {
+		if strings.HasPrefix(flagArg, "-") && strings.HasPrefix(flagArg, "--") == false && len(flagArg) > 2 {
+			for _, flagChar := range flagArg[1:] {
+				flagArgsSeparated = append(flagArgsSeparated, "-"+string(flagChar))
+			}
+		} else {
+			flagArgsSeparated = append(flagArgsSeparated, flagArg)
+		}
+	}
+	return flagArgsSeparated
+}
+
 // Names returns the names including short names and aliases.
 func (c Command) Names() []string {
 	names := []string{c.Name}

command_test.go

@@ -11,20 +11,24 @@ import (
 
 func TestCommandFlagParsing(t *testing.T) {
 	cases := []struct {
-		testArgs        []string
-		skipFlagParsing bool
-		skipArgReorder  bool
-		expectedErr     error
+		testArgs               []string
+		skipFlagParsing        bool
+		skipArgReorder         bool
+		expectedErr            error
+		UseShortOptionHandling bool
 	}{
 		// Test normal "not ignoring flags" flow
-		{[]string{"test-cmd", "blah", "blah", "-break"}, false, false, errors.New("flag provided but not defined: -break")},
+		{[]string{"test-cmd", "blah", "blah", "-break"}, false, false, errors.New("flag provided but not defined: -break"), false},
 
 		// Test no arg reorder
-		{[]string{"test-cmd", "blah", "blah", "-break"}, false, true, nil},
+		{[]string{"test-cmd", "blah", "blah", "-break"}, false, true, nil, false},
+		{[]string{"test-cmd", "blah", "blah", "-break", "ls", "-l"}, false, true, nil, true},
+
+		{[]string{"test-cmd", "blah", "blah"}, true, false, nil, false},   // Test SkipFlagParsing without any args that look like flags
+		{[]string{"test-cmd", "blah", "-break"}, true, false, nil, false}, // Test SkipFlagParsing with random flag arg
+		{[]string{"test-cmd", "blah", "-help"}, true, false, nil, false},  // Test SkipFlagParsing with "special" help flag arg
+		{[]string{"test-cmd", "blah"}, false, false, nil, true},           // Test UseShortOptionHandling
 
-		{[]string{"test-cmd", "blah", "blah"}, true, false, nil},   // Test SkipFlagParsing without any args that look like flags
-		{[]string{"test-cmd", "blah", "-break"}, true, false, nil}, // Test SkipFlagParsing with random flag arg
-		{[]string{"test-cmd", "blah", "-help"}, true, false, nil},  // Test SkipFlagParsing with "special" help flag arg
 	}
 
 	for _, c := range cases {
@@ -36,13 +40,14 @@ func TestCommandFlagParsing(t *testing.T) {
 		context := NewContext(app, set, nil)
 
 		command := Command{
-			Name:            "test-cmd",
-			Aliases:         []string{"tc"},
-			Usage:           "this is for testing",
-			Description:     "testing",
-			Action:          func(_ *Context) error { return nil },
-			SkipFlagParsing: c.skipFlagParsing,
-			SkipArgReorder:  c.skipArgReorder,
+			Name:                   "test-cmd",
+			Aliases:                []string{"tc"},
+			Usage:                  "this is for testing",
+			Description:            "testing",
+			Action:                 func(_ *Context) error { return nil },
+			SkipFlagParsing:        c.skipFlagParsing,
+			SkipArgReorder:         c.skipArgReorder,
+			UseShortOptionHandling: c.UseShortOptionHandling,
 		}
 
 		err := command.Run(context)
@@ -238,3 +243,77 @@ func TestCommand_Run_SubcommandsCanUseErrWriter(t *testing.T) {
 		t.Fatal(err)
 	}
 }
+
+func TestCommandFlagReordering(t *testing.T) {
+	cases := []struct {
+		testArgs      []string
+		expectedValue string
+		expectedArgs  []string
+		expectedErr   error
+	}{
+		{[]string{"some-exec", "some-command", "some-arg", "--flag", "foo"}, "foo", []string{"some-arg"}, nil},
+		{[]string{"some-exec", "some-command", "some-arg", "--flag=foo"}, "foo", []string{"some-arg"}, nil},
+		{[]string{"some-exec", "some-command", "--flag=foo", "some-arg"}, "foo", []string{"some-arg"}, nil},
+	}
+
+	for _, c := range cases {
+		value := ""
+		args := []string{}
+		app := &App{
+			Commands: []Command{
+				{
+					Name: "some-command",
+					Flags: []Flag{
+						StringFlag{Name: "flag"},
+					},
+					Action: func(c *Context) {
+						fmt.Printf("%+v\n", c.String("flag"))
+						value = c.String("flag")
+						args = c.Args()
+					},
+				},
+			},
+		}
+
+		err := app.Run(c.testArgs)
+		expect(t, err, c.expectedErr)
+		expect(t, value, c.expectedValue)
+		expect(t, args, c.expectedArgs)
+	}
+}
+
+func TestCommandSkipFlagParsing(t *testing.T) {
+	cases := []struct {
+		testArgs     []string
+		expectedArgs []string
+		expectedErr  error
+	}{
+		{[]string{"some-exec", "some-command", "some-arg", "--flag", "foo"}, []string{"some-arg", "--flag", "foo"}, nil},
+		{[]string{"some-exec", "some-command", "some-arg", "--flag=foo"}, []string{"some-arg", "--flag=foo"}, nil},
+	}
+
+	for _, c := range cases {
+		value := ""
+		args := []string{}
+		app := &App{
+			Commands: []Command{
+				{
+					SkipFlagParsing: true,
+					Name:            "some-command",
+					Flags: []Flag{
+						StringFlag{Name: "flag"},
+					},
+					Action: func(c *Context) {
+						fmt.Printf("%+v\n", c.String("flag"))
+						value = c.String("flag")
+						args = c.Args()
+					},
+				},
+			},
+		}
+
+		err := app.Run(c.testArgs)
+		expect(t, err, c.expectedErr)
+		expect(t, args, c.expectedArgs)
+	}
+}

context.go

@@ -3,6 +3,7 @@ package cli
 import (
 	"errors"
 	"flag"
+	"os"
 	"reflect"
 	"strings"
 	"syscall"
@@ -73,7 +74,7 @@ func (c *Context) IsSet(name string) bool {
 		// change in version 2 to add `IsSet` to the Flag interface to push the
 		// responsibility closer to where the information required to determine
 		// whether a flag is set by non-standard means such as environment
-		// variables is avaliable.
+		// variables is available.
 		//
 		// See https://github.com/urfave/cli/issues/294 for additional discussion
 		flags := c.Command.Flags
@@ -93,18 +94,26 @@ func (c *Context) IsSet(name string) bool {
 					val = val.Elem()
 				}
 
-				envVarValue := val.FieldByName("EnvVar")
-				if !envVarValue.IsValid() {
-					return
+				filePathValue := val.FieldByName("FilePath")
+				if filePathValue.IsValid() {
+					eachName(filePathValue.String(), func(filePath string) {
+						if _, err := os.Stat(filePath); err == nil {
+							c.setFlags[name] = true
+							return
+						}
+					})
 				}
 
-				eachName(envVarValue.String(), func(envVar string) {
-					envVar = strings.TrimSpace(envVar)
-					if _, ok := syscall.Getenv(envVar); ok {
-						c.setFlags[name] = true
-						return
-					}
-				})
+				envVarValue := val.FieldByName("EnvVar")
+				if envVarValue.IsValid() {
+					eachName(envVarValue.String(), func(envVar string) {
+						envVar = strings.TrimSpace(envVar)
+						if _, ok := syscall.Getenv(envVar); ok {
+							c.setFlags[name] = true
+							return
+						}
+					})
+				}
 			})
 		}
 	}

flag.go

@@ -3,6 +3,7 @@ package cli
 import (
 	"flag"
 	"fmt"
+	"io/ioutil"
 	"reflect"
 	"runtime"
 	"strconv"
@@ -37,6 +38,18 @@ var HelpFlag Flag = BoolFlag{
 // to display a flag.
 var FlagStringer FlagStringFunc = stringifyFlag
 
+// FlagNamePrefixer converts a full flag name and its placeholder into the help
+// message flag prefix. This is used by the default FlagStringer.
+var FlagNamePrefixer FlagNamePrefixFunc = prefixedNames
+
+// FlagEnvHinter annotates flag help message with the environment variable
+// details. This is used by the default FlagStringer.
+var FlagEnvHinter FlagEnvHintFunc = withEnvHint
+
+// FlagFileHinter annotates flag help message with the environment variable
+// details. This is used by the default FlagStringer.
+var FlagFileHinter FlagFileHintFunc = withFileHint
+
 // FlagsByName is a slice of Flag.
 type FlagsByName []Flag
 
@@ -45,7 +58,7 @@ func (f FlagsByName) Len() int {
 }
 
 func (f FlagsByName) Less(i, j int) bool {
-	return f[i].GetName() < f[j].GetName()
+	return lexicographicLess(f[i].GetName(), f[j].GetName())
 }
 
 func (f FlagsByName) Swap(i, j int) {
@@ -112,15 +125,9 @@ func (f GenericFlag) Apply(set *flag.FlagSet) {
 // provided by the user for parsing by the flag
 func (f GenericFlag) ApplyWithError(set *flag.FlagSet) error {
 	val := f.Value
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				if err := val.Set(envVal); err != nil {
-					return fmt.Errorf("could not parse %s as value for flag %s: %s", envVal, f.Name, err)
-				}
-				break
-			}
+	if fileEnvVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		if err := val.Set(fileEnvVal); err != nil {
+			return fmt.Errorf("could not parse %s as value for flag %s: %s", fileEnvVal, f.Name, err)
 		}
 	}
 
@@ -163,21 +170,19 @@ func (f StringSliceFlag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f StringSliceFlag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				newVal := &StringSlice{}
-				for _, s := range strings.Split(envVal, ",") {
-					s = strings.TrimSpace(s)
-					if err := newVal.Set(s); err != nil {
-						return fmt.Errorf("could not parse %s as string value for flag %s: %s", envVal, f.Name, err)
-					}
-				}
-				f.Value = newVal
-				break
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		newVal := &StringSlice{}
+		for _, s := range strings.Split(envVal, ",") {
+			s = strings.TrimSpace(s)
+			if err := newVal.Set(s); err != nil {
+				return fmt.Errorf("could not parse %s as string value for flag %s: %s", envVal, f.Name, err)
 			}
 		}
+		if f.Value == nil {
+			f.Value = newVal
+		} else {
+			*f.Value = *newVal
+		}
 	}
 
 	eachName(f.Name, func(name string) {
@@ -226,21 +231,19 @@ func (f IntSliceFlag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f IntSliceFlag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				newVal := &IntSlice{}
-				for _, s := range strings.Split(envVal, ",") {
-					s = strings.TrimSpace(s)
-					if err := newVal.Set(s); err != nil {
-						return fmt.Errorf("could not parse %s as int slice value for flag %s: %s", envVal, f.Name, err)
-					}
-				}
-				f.Value = newVal
-				break
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		newVal := &IntSlice{}
+		for _, s := range strings.Split(envVal, ",") {
+			s = strings.TrimSpace(s)
+			if err := newVal.Set(s); err != nil {
+				return fmt.Errorf("could not parse %s as int slice value for flag %s: %s", envVal, f.Name, err)
 			}
 		}
+		if f.Value == nil {
+			f.Value = newVal
+		} else {
+			*f.Value = *newVal
+		}
 	}
 
 	eachName(f.Name, func(name string) {
@@ -289,21 +292,19 @@ func (f Int64SliceFlag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f Int64SliceFlag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				newVal := &Int64Slice{}
-				for _, s := range strings.Split(envVal, ",") {
-					s = strings.TrimSpace(s)
-					if err := newVal.Set(s); err != nil {
-						return fmt.Errorf("could not parse %s as int64 slice value for flag %s: %s", envVal, f.Name, err)
-					}
-				}
-				f.Value = newVal
-				break
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		newVal := &Int64Slice{}
+		for _, s := range strings.Split(envVal, ",") {
+			s = strings.TrimSpace(s)
+			if err := newVal.Set(s); err != nil {
+				return fmt.Errorf("could not parse %s as int64 slice value for flag %s: %s", envVal, f.Name, err)
 			}
 		}
+		if f.Value == nil {
+			f.Value = newVal
+		} else {
+			*f.Value = *newVal
+		}
 	}
 
 	eachName(f.Name, func(name string) {
@@ -324,23 +325,15 @@ func (f BoolFlag) Apply(set *flag.FlagSet) {
 // ApplyWithError populates the flag given the flag set and environment
 func (f BoolFlag) ApplyWithError(set *flag.FlagSet) error {
 	val := false
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				if envVal == "" {
-					val = false
-					break
-				}
-
-				envValBool, err := strconv.ParseBool(envVal)
-				if err != nil {
-					return fmt.Errorf("could not parse %s as bool value for flag %s: %s", envVal, f.Name, err)
-				}
-
-				val = envValBool
-				break
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		if envVal == "" {
+			val = false
+		} else {
+			envValBool, err := strconv.ParseBool(envVal)
+			if err != nil {
+				return fmt.Errorf("could not parse %s as bool value for flag %s: %s", envVal, f.Name, err)
 			}
+			val = envValBool
 		}
 	}
 
@@ -364,23 +357,16 @@ func (f BoolTFlag) Apply(set *flag.FlagSet) {
 // ApplyWithError populates the flag given the flag set and environment
 func (f BoolTFlag) ApplyWithError(set *flag.FlagSet) error {
 	val := true
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				if envVal == "" {
-					val = false
-					break
-				}
 
-				envValBool, err := strconv.ParseBool(envVal)
-				if err != nil {
-					return fmt.Errorf("could not parse %s as bool value for flag %s: %s", envVal, f.Name, err)
-				}
-
-				val = envValBool
-				break
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		if envVal == "" {
+			val = false
+		} else {
+			envValBool, err := strconv.ParseBool(envVal)
+			if err != nil {
+				return fmt.Errorf("could not parse %s as bool value for flag %s: %s", envVal, f.Name, err)
 			}
+			val = envValBool
 		}
 	}
 
@@ -403,14 +389,8 @@ func (f StringFlag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f StringFlag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				f.Value = envVal
-				break
-			}
-		}
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		f.Value = envVal
 	}
 
 	eachName(f.Name, func(name string) {
@@ -432,18 +412,12 @@ func (f IntFlag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f IntFlag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				envValInt, err := strconv.ParseInt(envVal, 0, 64)
-				if err != nil {
-					return fmt.Errorf("could not parse %s as int value for flag %s: %s", envVal, f.Name, err)
-				}
-				f.Value = int(envValInt)
-				break
-			}
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		envValInt, err := strconv.ParseInt(envVal, 0, 64)
+		if err != nil {
+			return fmt.Errorf("could not parse %s as int value for flag %s: %s", envVal, f.Name, err)
 		}
+		f.Value = int(envValInt)
 	}
 
 	eachName(f.Name, func(name string) {
@@ -465,19 +439,13 @@ func (f Int64Flag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f Int64Flag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				envValInt, err := strconv.ParseInt(envVal, 0, 64)
-				if err != nil {
-					return fmt.Errorf("could not parse %s as int value for flag %s: %s", envVal, f.Name, err)
-				}
-
-				f.Value = envValInt
-				break
-			}
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		envValInt, err := strconv.ParseInt(envVal, 0, 64)
+		if err != nil {
+			return fmt.Errorf("could not parse %s as int value for flag %s: %s", envVal, f.Name, err)
 		}
+
+		f.Value = envValInt
 	}
 
 	eachName(f.Name, func(name string) {
@@ -499,19 +467,13 @@ func (f UintFlag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f UintFlag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				envValInt, err := strconv.ParseUint(envVal, 0, 64)
-				if err != nil {
-					return fmt.Errorf("could not parse %s as uint value for flag %s: %s", envVal, f.Name, err)
-				}
-
-				f.Value = uint(envValInt)
-				break
-			}
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		envValInt, err := strconv.ParseUint(envVal, 0, 64)
+		if err != nil {
+			return fmt.Errorf("could not parse %s as uint value for flag %s: %s", envVal, f.Name, err)
 		}
+
+		f.Value = uint(envValInt)
 	}
 
 	eachName(f.Name, func(name string) {
@@ -533,19 +495,13 @@ func (f Uint64Flag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f Uint64Flag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				envValInt, err := strconv.ParseUint(envVal, 0, 64)
-				if err != nil {
-					return fmt.Errorf("could not parse %s as uint64 value for flag %s: %s", envVal, f.Name, err)
-				}
-
-				f.Value = uint64(envValInt)
-				break
-			}
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		envValInt, err := strconv.ParseUint(envVal, 0, 64)
+		if err != nil {
+			return fmt.Errorf("could not parse %s as uint64 value for flag %s: %s", envVal, f.Name, err)
 		}
+
+		f.Value = uint64(envValInt)
 	}
 
 	eachName(f.Name, func(name string) {
@@ -567,19 +523,13 @@ func (f DurationFlag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f DurationFlag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				envValDuration, err := time.ParseDuration(envVal)
-				if err != nil {
-					return fmt.Errorf("could not parse %s as duration for flag %s: %s", envVal, f.Name, err)
-				}
-
-				f.Value = envValDuration
-				break
-			}
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		envValDuration, err := time.ParseDuration(envVal)
+		if err != nil {
+			return fmt.Errorf("could not parse %s as duration for flag %s: %s", envVal, f.Name, err)
 		}
+
+		f.Value = envValDuration
 	}
 
 	eachName(f.Name, func(name string) {
@@ -601,19 +551,13 @@ func (f Float64Flag) Apply(set *flag.FlagSet) {
 
 // ApplyWithError populates the flag given the flag set and environment
 func (f Float64Flag) ApplyWithError(set *flag.FlagSet) error {
-	if f.EnvVar != "" {
-		for _, envVar := range strings.Split(f.EnvVar, ",") {
-			envVar = strings.TrimSpace(envVar)
-			if envVal, ok := syscall.Getenv(envVar); ok {
-				envValFloat, err := strconv.ParseFloat(envVal, 10)
-				if err != nil {
-					return fmt.Errorf("could not parse %s as float64 value for flag %s: %s", envVal, f.Name, err)
-				}
-
-				f.Value = float64(envValFloat)
-				break
-			}
+	if envVal, ok := flagFromFileEnv(f.FilePath, f.EnvVar); ok {
+		envValFloat, err := strconv.ParseFloat(envVal, 10)
+		if err != nil {
+			return fmt.Errorf("could not parse %s as float64 value for flag %s: %s", envVal, f.Name, err)
 		}
+
+		f.Value = float64(envValFloat)
 	}
 
 	eachName(f.Name, func(name string) {
@@ -692,11 +636,19 @@ func withEnvHint(envVar, str string) string {
 			suffix = "%"
 			sep = "%, %"
 		}
-		envText = fmt.Sprintf(" [%s%s%s]", prefix, strings.Join(strings.Split(envVar, ","), sep), suffix)
+		envText = " [" + prefix + strings.Join(strings.Split(envVar, ","), sep) + suffix + "]"
 	}
 	return str + envText
 }
 
+func withFileHint(filePath, str string) string {
+	fileText := ""
+	if filePath != "" {
+		fileText = fmt.Sprintf(" [%s]", filePath)
+	}
+	return str + fileText
+}
+
 func flagValue(f Flag) reflect.Value {
 	fv := reflect.ValueOf(f)
 	for fv.Kind() == reflect.Ptr {
@@ -710,14 +662,29 @@ func stringifyFlag(f Flag) string {
 
 	switch f.(type) {
 	case IntSliceFlag:
-		return withEnvHint(fv.FieldByName("EnvVar").String(),
-			stringifyIntSliceFlag(f.(IntSliceFlag)))
+		return FlagFileHinter(
+			fv.FieldByName("FilePath").String(),
+			FlagEnvHinter(
+				fv.FieldByName("EnvVar").String(),
+				stringifyIntSliceFlag(f.(IntSliceFlag)),
+			),
+		)
 	case Int64SliceFlag:
-		return withEnvHint(fv.FieldByName("EnvVar").String(),
-			stringifyInt64SliceFlag(f.(Int64SliceFlag)))
+		return FlagFileHinter(
+			fv.FieldByName("FilePath").String(),
+			FlagEnvHinter(
+				fv.FieldByName("EnvVar").String(),
+				stringifyInt64SliceFlag(f.(Int64SliceFlag)),
+			),
+		)
 	case StringSliceFlag:
-		return withEnvHint(fv.FieldByName("EnvVar").String(),
-			stringifyStringSliceFlag(f.(StringSliceFlag)))
+		return FlagFileHinter(
+			fv.FieldByName("FilePath").String(),
+			FlagEnvHinter(
+				fv.FieldByName("EnvVar").String(),
+				stringifyStringSliceFlag(f.(StringSliceFlag)),
+			),
+		)
 	}
 
 	placeholder, usage := unquoteUsage(fv.FieldByName("Usage").String())
@@ -742,17 +709,22 @@ func stringifyFlag(f Flag) string {
 		placeholder = defaultPlaceholder
 	}
 
-	usageWithDefault := strings.TrimSpace(fmt.Sprintf("%s%s", usage, defaultValueString))
+	usageWithDefault := strings.TrimSpace(usage + defaultValueString)
 
-	return withEnvHint(fv.FieldByName("EnvVar").String(),
-		fmt.Sprintf("%s\t%s", prefixedNames(fv.FieldByName("Name").String(), placeholder), usageWithDefault))
+	return FlagFileHinter(
+		fv.FieldByName("FilePath").String(),
+		FlagEnvHinter(
+			fv.FieldByName("EnvVar").String(),
+			FlagNamePrefixer(fv.FieldByName("Name").String(), placeholder)+"\t"+usageWithDefault,
+		),
+	)
 }
 
 func stringifyIntSliceFlag(f IntSliceFlag) string {
 	defaultVals := []string{}
 	if f.Value != nil && len(f.Value.Value()) > 0 {
 		for _, i := range f.Value.Value() {
-			defaultVals = append(defaultVals, fmt.Sprintf("%d", i))
+			defaultVals = append(defaultVals, strconv.Itoa(i))
 		}
 	}
 
@@ -763,7 +735,7 @@ func stringifyInt64SliceFlag(f Int64SliceFlag) string {
 	defaultVals := []string{}
 	if f.Value != nil && len(f.Value.Value()) > 0 {
 		for _, i := range f.Value.Value() {
-			defaultVals = append(defaultVals, fmt.Sprintf("%d", i))
+			defaultVals = append(defaultVals, strconv.FormatInt(i, 10))
 		}
 	}
 
@@ -775,7 +747,7 @@ func stringifyStringSliceFlag(f StringSliceFlag) string {
 	if f.Value != nil && len(f.Value.Value()) > 0 {
 		for _, s := range f.Value.Value() {
 			if len(s) > 0 {
-				defaultVals = append(defaultVals, fmt.Sprintf("%q", s))
+				defaultVals = append(defaultVals, strconv.Quote(s))
 			}
 		}
 	}
@@ -794,6 +766,21 @@ func stringifySliceFlag(usage, name string, defaultVals []string) string {
 		defaultVal = fmt.Sprintf(" (default: %s)", strings.Join(defaultVals, ", "))
 	}
 
-	usageWithDefault := strings.TrimSpace(fmt.Sprintf("%s%s", usage, defaultVal))
-	return fmt.Sprintf("%s\t%s", prefixedNames(name, placeholder), usageWithDefault)
+	usageWithDefault := strings.TrimSpace(usage + defaultVal)
+	return FlagNamePrefixer(name, placeholder) + "\t" + usageWithDefault
+}
+
+func flagFromFileEnv(filePath, envName string) (val string, ok bool) {
+	for _, envVar := range strings.Split(envName, ",") {
+		envVar = strings.TrimSpace(envVar)
+		if envVal, ok := syscall.Getenv(envVar); ok {
+			return envVal, true
+		}
+	}
+	for _, fileVar := range strings.Split(filePath, ",") {
+		if data, err := ioutil.ReadFile(fileVar); err == nil {
+			return string(data), true
+		}
+	}
+	return "", false
 }

flag_generated.go

@@ -13,6 +13,7 @@ type BoolFlag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Destination *bool
 }
@@ -60,6 +61,7 @@ type BoolTFlag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Destination *bool
 }
@@ -107,6 +109,7 @@ type DurationFlag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Value       time.Duration
 	Destination *time.Duration
@@ -155,6 +158,7 @@ type Float64Flag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Value       float64
 	Destination *float64
@@ -200,11 +204,12 @@ func lookupFloat64(name string, set *flag.FlagSet) float64 {
 
 // GenericFlag is a flag with type Generic
 type GenericFlag struct {
-	Name   string
-	Usage  string
-	EnvVar string
-	Hidden bool
-	Value  Generic
+	Name     string
+	Usage    string
+	EnvVar   string
+	FilePath string
+	Hidden   bool
+	Value    Generic
 }
 
 // String returns a readable representation of this value
@@ -250,6 +255,7 @@ type Int64Flag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Value       int64
 	Destination *int64
@@ -298,6 +304,7 @@ type IntFlag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Value       int
 	Destination *int
@@ -343,11 +350,12 @@ func lookupInt(name string, set *flag.FlagSet) int {
 
 // IntSliceFlag is a flag with type *IntSlice
 type IntSliceFlag struct {
-	Name   string
-	Usage  string
-	EnvVar string
-	Hidden bool
-	Value  *IntSlice
+	Name     string
+	Usage    string
+	EnvVar   string
+	FilePath string
+	Hidden   bool
+	Value    *IntSlice
 }
 
 // String returns a readable representation of this value
@@ -390,11 +398,12 @@ func lookupIntSlice(name string, set *flag.FlagSet) []int {
 
 // Int64SliceFlag is a flag with type *Int64Slice
 type Int64SliceFlag struct {
-	Name   string
-	Usage  string
-	EnvVar string
-	Hidden bool
-	Value  *Int64Slice
+	Name     string
+	Usage    string
+	EnvVar   string
+	FilePath string
+	Hidden   bool
+	Value    *Int64Slice
 }
 
 // String returns a readable representation of this value
@@ -440,6 +449,7 @@ type StringFlag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Value       string
 	Destination *string
@@ -485,11 +495,12 @@ func lookupString(name string, set *flag.FlagSet) string {
 
 // StringSliceFlag is a flag with type *StringSlice
 type StringSliceFlag struct {
-	Name   string
-	Usage  string
-	EnvVar string
-	Hidden bool
-	Value  *StringSlice
+	Name     string
+	Usage    string
+	EnvVar   string
+	FilePath string
+	Hidden   bool
+	Value    *StringSlice
 }
 
 // String returns a readable representation of this value
@@ -535,6 +546,7 @@ type Uint64Flag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Value       uint64
 	Destination *uint64
@@ -583,6 +595,7 @@ type UintFlag struct {
 	Name        string
 	Usage       string
 	EnvVar      string
+	FilePath    string
 	Hidden      bool
 	Value       uint
 	Destination *uint

flag_test.go

@@ -2,6 +2,8 @@ package cli
 
 import (
 	"fmt"
+	"io"
+	"io/ioutil"
 	"os"
 	"reflect"
 	"regexp"
@@ -158,6 +160,83 @@ func TestStringFlagWithEnvVarHelpOutput(t *testing.T) {
 	}
 }
 
+var prefixStringFlagTests = []struct {
+	name     string
+	usage    string
+	value    string
+	prefixer FlagNamePrefixFunc
+	expected string
+}{
+	{"foo", "", "", func(a, b string) string {
+		return fmt.Sprintf("name: %s, ph: %s", a, b)
+	}, "name: foo, ph: value\t"},
+	{"f", "", "", func(a, b string) string {
+		return fmt.Sprintf("name: %s, ph: %s", a, b)
+	}, "name: f, ph: value\t"},
+	{"f", "The total `foo` desired", "all", func(a, b string) string {
+		return fmt.Sprintf("name: %s, ph: %s", a, b)
+	}, "name: f, ph: foo\tThe total foo desired (default: \"all\")"},
+	{"test", "", "Something", func(a, b string) string {
+		return fmt.Sprintf("name: %s, ph: %s", a, b)
+	}, "name: test, ph: value\t(default: \"Something\")"},
+	{"config,c", "Load configuration from `FILE`", "", func(a, b string) string {
+		return fmt.Sprintf("name: %s, ph: %s", a, b)
+	}, "name: config,c, ph: FILE\tLoad configuration from FILE"},
+	{"config,c", "Load configuration from `CONFIG`", "config.json", func(a, b string) string {
+		return fmt.Sprintf("name: %s, ph: %s", a, b)
+	}, "name: config,c, ph: CONFIG\tLoad configuration from CONFIG (default: \"config.json\")"},
+}
+
+func TestFlagNamePrefixer(t *testing.T) {
+	defer func() {
+		FlagNamePrefixer = prefixedNames
+	}()
+
+	for _, test := range prefixStringFlagTests {
+		FlagNamePrefixer = test.prefixer
+		flag := StringFlag{Name: test.name, Usage: test.usage, Value: test.value}
+		output := flag.String()
+		if output != test.expected {
+			t.Errorf("%q does not match %q", output, test.expected)
+		}
+	}
+}
+
+var envHintFlagTests = []struct {
+	name     string
+	env      string
+	hinter   FlagEnvHintFunc
+	expected string
+}{
+	{"foo", "", func(a, b string) string {
+		return fmt.Sprintf("env: %s, str: %s", a, b)
+	}, "env: , str: --foo value\t"},
+	{"f", "", func(a, b string) string {
+		return fmt.Sprintf("env: %s, str: %s", a, b)
+	}, "env: , str: -f value\t"},
+	{"foo", "ENV_VAR", func(a, b string) string {
+		return fmt.Sprintf("env: %s, str: %s", a, b)
+	}, "env: ENV_VAR, str: --foo value\t"},
+	{"f", "ENV_VAR", func(a, b string) string {
+		return fmt.Sprintf("env: %s, str: %s", a, b)
+	}, "env: ENV_VAR, str: -f value\t"},
+}
+
+func TestFlagEnvHinter(t *testing.T) {
+	defer func() {
+		FlagEnvHinter = withEnvHint
+	}()
+
+	for _, test := range envHintFlagTests {
+		FlagEnvHinter = test.hinter
+		flag := StringFlag{Name: test.name, EnvVar: test.env}
+		output := flag.String()
+		if output != test.expected {
+			t.Errorf("%q does not match %q", output, test.expected)
+		}
+	}
+}
+
 var stringSliceFlagTests = []struct {
 	name     string
 	value    *StringSlice
@@ -969,6 +1048,31 @@ func TestParseMultiBool(t *testing.T) {
 	a.Run([]string{"run", "--serve"})
 }
 
+func TestParseBoolShortOptionHandle(t *testing.T) {
+	a := App{
+		Commands: []Command{
+			{
+				Name: "foobar",
+				UseShortOptionHandling: true,
+				Action: func(ctx *Context) error {
+					if ctx.Bool("serve") != true {
+						t.Errorf("main name not set")
+					}
+					if ctx.Bool("option") != true {
+						t.Errorf("short name not set")
+					}
+					return nil
+				},
+				Flags: []Flag{
+					BoolFlag{Name: "serve, s"},
+					BoolFlag{Name: "option, o"},
+				},
+			},
+		},
+	}
+	a.Run([]string{"run", "foobar", "-so"})
+}
+
 func TestParseDestinationBool(t *testing.T) {
 	var dest bool
 	a := App{
@@ -1213,3 +1317,38 @@ func TestParseGenericFromEnvCascade(t *testing.T) {
 	}
 	a.Run([]string{"run"})
 }
+
+func TestFlagFromFile(t *testing.T) {
+	os.Clearenv()
+	os.Setenv("APP_FOO", "123")
+
+	temp, err := ioutil.TempFile("", "urfave_cli_test")
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	io.WriteString(temp, "abc")
+	temp.Close()
+	defer func() {
+		os.Remove(temp.Name())
+	}()
+
+	var filePathTests = []struct {
+		path     string
+		name     string
+		expected string
+	}{
+		{"file-does-not-exist", "APP_BAR", ""},
+		{"file-does-not-exist", "APP_FOO", "123"},
+		{"file-does-not-exist", "APP_FOO,APP_BAR", "123"},
+		{temp.Name(), "APP_FOO", "123"},
+		{temp.Name(), "APP_BAR", "abc"},
+	}
+
+	for _, filePathTest := range filePathTests {
+		got, _ := flagFromFileEnv(filePathTest.path, filePathTest.name)
+		if want := filePathTest.expected; got != want {
+			t.Errorf("Did not expect %v - Want %v", got, want)
+		}
+	}
+}

funcs.go

@@ -23,6 +23,22 @@ type CommandNotFoundFunc func(*Context, string)
 // is displayed and the execution is interrupted.
 type OnUsageErrorFunc func(context *Context, err error, isSubcommand bool) error
 
+// ExitErrHandlerFunc is executed if provided in order to handle ExitError values
+// returned by Actions and Before/After functions.
+type ExitErrHandlerFunc func(context *Context, err error)
+
 // FlagStringFunc is used by the help generation to display a flag, which is
 // expected to be a single line.
 type FlagStringFunc func(Flag) string
+
+// FlagNamePrefixFunc is used by the default FlagStringFunc to create prefix
+// text for a flag's full name.
+type FlagNamePrefixFunc func(fullName, placeholder string) string
+
+// FlagEnvHintFunc is used by the default FlagStringFunc to annotate flag help
+// with the environment variable details.
+type FlagEnvHintFunc func(envVar, str string) string
+
+// FlagFileHintFunc is used by the default FlagStringFunc to annotate flag help
+// with the file path details.
+type FlagFileHintFunc func(filePath, str string) string

generate-flag-types

@@ -142,6 +142,7 @@ def _write_cli_flag_types(outfile, types):
             Name string
             Usage string
             EnvVar string
+            FilePath string
             Hidden bool
         """.format(**typedef))
 

help.go

@@ -29,6 +29,7 @@ AUTHOR{{with $length := len .Authors}}{{if ne 1 $length}}S{{end}}{{end}}:
    {{end}}{{$author}}{{end}}{{end}}{{if .VisibleCommands}}
 
 COMMANDS:{{range .VisibleCategories}}{{if .Name}}
+
    {{.Name}}:{{end}}{{range .VisibleCommands}}
      {{join .Names ", "}}{{"\t"}}{{.Usage}}{{end}}{{end}}{{end}}{{if .VisibleFlags}}
 
@@ -157,8 +158,14 @@ func DefaultAppComplete(c *Context) {
 		if command.Hidden {
 			continue
 		}
-		for _, name := range command.Names() {
-			fmt.Fprintln(c.App.Writer, name)
+		if os.Getenv("_CLI_ZSH_AUTOCOMPLETE_HACK") == "1" {
+			for _, name := range command.Names() {
+				fmt.Fprintf(c.App.Writer, "%s:%s\n", name, command.Usage)
+			}
+		} else {
+			for _, name := range command.Names() {
+				fmt.Fprintf(c.App.Writer, "%s\n", name)
+			}
 		}
 	}
 }

sort.go

@@ -0,0 +1,29 @@
+package cli
+
+import "unicode"
+
+// lexicographicLess compares strings alphabetically considering case.
+func lexicographicLess(i, j string) bool {
+	iRunes := []rune(i)
+	jRunes := []rune(j)
+
+	lenShared := len(iRunes)
+	if lenShared > len(jRunes) {
+		lenShared = len(jRunes)
+	}
+
+	for index := 0; index < lenShared; index++ {
+		ir := iRunes[index]
+		jr := jRunes[index]
+
+		if lir, ljr := unicode.ToLower(ir), unicode.ToLower(jr); lir != ljr {
+			return lir < ljr
+		}
+
+		if ir != jr {
+			return ir < jr
+		}
+	}
+
+	return i < j
+}

sort_test.go

@@ -0,0 +1,30 @@
+package cli
+
+import "testing"
+
+var lexicographicLessTests = []struct {
+	i        string
+	j        string
+	expected bool
+}{
+	{"", "a", true},
+	{"a", "", false},
+	{"a", "a", false},
+	{"a", "A", false},
+	{"A", "a", true},
+	{"aa", "a", false},
+	{"a", "aa", true},
+	{"a", "b", true},
+	{"a", "B", true},
+	{"A", "b", true},
+	{"A", "B", true},
+}
+
+func TestLexicographicLess(t *testing.T) {
+	for _, test := range lexicographicLessTests {
+		actual := lexicographicLess(test.i, test.j)
+		if test.expected != actual {
+			t.Errorf(`expected string "%s" to come before "%s"`, test.i, test.j)
+		}
+	}
+}