syncthing/github.com/jessevdk/go-flags/ini.go
2013-12-23 11:18:46 -05:00

147 lines
4.0 KiB
Go

package flags
import (
"fmt"
"io"
"os"
)
// IniError contains location information on where in the ini file an error
// occured.
type IniError struct {
// The error message.
Message string
// The filename of the file in which the error occurred.
File string
// The line number at which the error occurred.
LineNumber uint
}
// Error provides a "file:line: message" formatted message of the ini error.
func (x *IniError) Error() string {
return fmt.Sprintf("%s:%d: %s",
x.File,
x.LineNumber,
x.Message)
}
// IniOptions for writing ini files
type IniOptions uint
const (
// IniNone indicates no options.
IniNone IniOptions = 0
// IniIncludeDefaults indicates that default values should be written
// when writing options to an ini file.
IniIncludeDefaults = 1 << iota
// IniIncludeComments indicates that comments containing the description
// of an option should be written when writing options to an ini file.
IniIncludeComments
// IniDefault provides a default set of options.
IniDefault = IniIncludeComments
)
// IniParser is a utility to read and write flags options from and to ini
// files.
type IniParser struct {
parser *Parser
}
// NewIniParser creates a new ini parser for a given Parser.
func NewIniParser(p *Parser) *IniParser {
return &IniParser{
parser: p,
}
}
// IniParse is a convenience function to parse command line options with default
// settings from an ini file. The provided data is a pointer to a struct
// representing the default option group (named "Application Options"). For
// more control, use flags.NewParser.
func IniParse(filename string, data interface{}) error {
p := NewParser(data, Default)
return NewIniParser(p).ParseFile(filename)
}
// ParseFile parses flags from an ini formatted file. See Parse for more
// information on the ini file foramt. The returned errors can be of the type
// flags.Error or flags.IniError.
func (i *IniParser) ParseFile(filename string) error {
i.parser.storeDefaults()
ini, err := readIniFromFile(filename)
if err != nil {
return err
}
return i.parse(ini)
}
// Parse parses flags from an ini format. You can use ParseFile as a
// convenience function to parse from a filename instead of a general
// io.Reader.
//
// The format of the ini file is as follows:
//
// [Option group name]
// option = value
//
// Each section in the ini file represents an option group or command in the
// flags parser. The default flags parser option group (i.e. when using
// flags.Parse) is named 'Application Options'. The ini option name is matched
// in the following order:
//
// 1. Compared to the ini-name tag on the option struct field (if present)
// 2. Compared to the struct field name
// 3. Compared to the option long name (if present)
// 4. Compared to the option short name (if present)
//
// Sections for nested groups and commands can be addressed using a dot `.'
// namespacing notation (i.e [subcommand.Options]). Group section names are
// matched case insensitive.
//
// The returned errors can be of the type flags.Error or
// flags.IniError.
func (i *IniParser) Parse(reader io.Reader) error {
i.parser.storeDefaults()
ini, err := readIni(reader, "")
if err != nil {
return err
}
return i.parse(ini)
}
// WriteFile writes the flags as ini format into a file. See WriteIni
// for more information. The returned error occurs when the specified file
// could not be opened for writing.
func (i *IniParser) WriteFile(filename string, options IniOptions) error {
file, err := os.Create(filename)
if err != nil {
return err
}
defer file.Close()
i.Write(file, options)
return nil
}
// Write writes the current values of all the flags to an ini format.
// See Parse for more information on the ini file format. You typically
// call this only after settings have been parsed since the default values of each
// option are stored just before parsing the flags (this is only relevant when
// IniIncludeDefaults is _not_ set in options).
func (i *IniParser) Write(writer io.Writer, options IniOptions) {
writeIni(i, writer, options)
}