document field in README
@@ -32,6 +32,7 @@ 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)
@@ -587,6 +588,38 @@ func main() {
}
```
+#### Values from Files
+
+You can also have the default value set from file via `FilePath`. e.g.
+
+<!-- {
+ "args": ["&#45;&#45;help"],
+ "output": "language for the greeting.*APP_LANG"
+} -->
+``` go
+package main
+
+import (
+ "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",
+ },
+ }
+
+ app.Run(os.Args)
+}
+```
+
#### Values from alternate input sources (YAML, TOML, and others)
There is a separate package altsrc that adds support for getting flag values
