Adding ini library

README.md

@@ -7,4 +7,5 @@ Libraries
     fs/inotify  - inotify library
     net/cluster - simple network cluster
     os/daemon   - daemonize library
+    util/ini    - ini file library
 

util/ini/ini.go

+// Package ini provides functions for parsing INI configuration files.
+package ini
+
+import (
+	"bufio"
+	"fmt"
+	"io"
+	"os"
+	"regexp"
+	"strings"
+)
+
+var (
+	sectionRegex = regexp.MustCompile(`^\[(.*)\]$`)
+	assignRegex  = regexp.MustCompile(`^([^=]+)=(.*)$`)
+)
+
+// ErrSyntax is returned when there is a syntax error in an INI file.
+type ErrSyntax struct {
+	Line   int
+	Source string // The contents of the erroneous line, without leading or trailing whitespace
+}
+
+func (e ErrSyntax) Error() string {
+	return fmt.Sprintf("invalid INI syntax on line %d: %s", e.Line, e.Source)
+}
+
+// A File represents a parsed INI file.
+type File map[string]Section
+
+// A Section represents a single section of an INI file.
+type Section map[string]string
+
+// Returns a named Section. A Section will be created if one does not already exist for the given name.
+func (f File) Section(name string) Section {
+	section := f[name]
+	if section == nil {
+		section = make(Section)
+		f[name] = section
+	}
+	return section
+}
+
+// Looks up a value for a key in a section and returns that value, along with a boolean result similar to a map lookup.
+func (f File) Get(section, key string) (value string, ok bool) {
+	if s := f[section]; s != nil {
+		value, ok = s[key]
+	}
+	return
+}
+
+// Loads INI data from a reader and stores the data in the File.
+func (f File) Load(in io.Reader) (err error) {
+	bufin, ok := in.(*bufio.Reader)
+	if !ok {
+		bufin = bufio.NewReader(in)
+	}
+	return parseFile(bufin, f)
+}
+
+// Loads INI data from a named file and stores the data in the File.
+func (f File) LoadFile(file string) (err error) {
+	in, err := os.Open(file)
+	if err != nil {
+		return
+	}
+	defer in.Close()
+	return f.Load(in)
+}
+
+func parseFile(in *bufio.Reader, file File) (err error) {
+	section := ""
+	lineNum := 0
+	for done := false; !done; {
+		var line string
+		if line, err = in.ReadString('\n'); err != nil {
+			if err == io.EOF {
+				done = true
+			} else {
+				return
+			}
+		}
+		lineNum++
+		line = strings.TrimSpace(line)
+		if len(line) == 0 {
+			// Skip blank lines
+			continue
+		}
+		if line[0] == ';' || line[0] == '#' {
+			// Skip comments
+			continue
+		}
+
+		if groups := assignRegex.FindStringSubmatch(line); groups != nil {
+			key, val := groups[1], groups[2]
+			key, val = strings.TrimSpace(key), strings.TrimSpace(val)
+			file.Section(section)[key] = val
+		} else if groups := sectionRegex.FindStringSubmatch(line); groups != nil {
+			name := strings.TrimSpace(groups[1])
+			section = name
+			// Create the section if it does not exist
+			file.Section(section)
+		} else {
+			return ErrSyntax{lineNum, line}
+		}
+
+	}
+	return nil
+}
+
+// Loads and returns a File from a reader.
+func Load(in io.Reader) (File, error) {
+	file := make(File)
+	err := file.Load(in)
+	return file, err
+}
+
+// Loads and returns an INI File from a file on disk.
+func LoadFile(filename string) (File, error) {
+	file := make(File)
+	err := file.LoadFile(filename)
+	return file, err
+}