nontransparent

Documentation

Overview

Example (BestEffortOnLastOne)

results := []syslog.Result{}
acc := func(res *syslog.Result) {
	results = append(results, *res)
}
r := strings.NewReader("<1>1 - - - - - - -\n<3>1\n")
NewParser(syslog.WithBestEffort(), syslog.WithListener(acc)).Parse(r)
output(results)

Output:

([]syslog.Result) (len=2) {
 (syslog.Result) {
  Message: (*rfc5424.SyslogMessage)({
   Base: (syslog.Base) {
    Facility: (*uint8)(0),
    Severity: (*uint8)(1),
    Priority: (*uint8)(1),
    Timestamp: (*time.Time)(<nil>),
    Hostname: (*string)(<nil>),
    Appname: (*string)(<nil>),
    ProcID: (*string)(<nil>),
    MsgID: (*string)(<nil>),
    Message: (*string)((len=1) "-")
   },
   Version: (uint16) 1,
   StructuredData: (*map[string]map[string]string)(<nil>)
  }),
  Error: (error) <nil>
 },
 (syslog.Result) {
  Message: (*rfc5424.SyslogMessage)({
   Base: (syslog.Base) {
    Facility: (*uint8)(0),
    Severity: (*uint8)(3),
    Priority: (*uint8)(3),
    Timestamp: (*time.Time)(<nil>),
    Hostname: (*string)(<nil>),
    Appname: (*string)(<nil>),
    ProcID: (*string)(<nil>),
    MsgID: (*string)(<nil>),
    Message: (*string)(<nil>)
   },
   Version: (uint16) 1,
   StructuredData: (*map[string]map[string]string)(<nil>)
  }),
  Error: (*errors.errorString)(parsing error [col 4])
 }
}

Example (BestEffortWithoutTrailerAtEnd)

results := []syslog.Result{}
acc := func(res *syslog.Result) {
	results = append(results, *res)
}
// Notice the message ends without trailer but we catch it anyway
r := strings.NewReader("<1>1 2003-10-11T22:14:15.003Z host.local - - - - mex")
NewParser(syslog.WithBestEffort(), syslog.WithListener(acc)).Parse(r)
output(results)

Output:

([]syslog.Result) (len=1) {
 (syslog.Result) {
  Message: (*rfc5424.SyslogMessage)({
   Base: (syslog.Base) {
    Facility: (*uint8)(0),
    Severity: (*uint8)(1),
    Priority: (*uint8)(1),
    Timestamp: (*time.Time)(2003-10-11 22:14:15.003 +0000 UTC),
    Hostname: (*string)((len=10) "host.local"),
    Appname: (*string)(<nil>),
    ProcID: (*string)(<nil>),
    MsgID: (*string)(<nil>),
    Message: (*string)((len=3) "mex")
   },
   Version: (uint16) 1,
   StructuredData: (*map[string]map[string]string)(<nil>)
  }),
  Error: (error) <nil>
 }
}

Example (IntoChannelWithLF)

messages := []string{
	"<2>1 - - - - - - A\nB",
	"<1>1 -",
	"<1>1 - - - - - - A\nB\nC\nD",
}

r, w := io.Pipe()

go func() {
	defer w.Close()

	for _, m := range messages {
		// Write message (containing trailers to be interpreted as part of the syslog MESSAGE)
		w.Write([]byte(m))
		// Write non-transparent frame boundary
		w.Write([]byte{10})
		// Wait a random amount of time
		time.Sleep(time.Millisecond * time.Duration(rand.Intn(100)))
	}
}()

results := make(chan *syslog.Result)
ln := func(x *syslog.Result) {
	// Emit the result
	results <- x
}

p := NewParser(syslog.WithListener(ln), syslog.WithBestEffort())
go func() {
	defer close(results)
	defer r.Close()
	p.Parse(r)
}()

// Consume results
for r := range results {
	output(r)
}

Output:

(*syslog.Result)({
 Message: (*rfc5424.SyslogMessage)({
  Base: (syslog.Base) {
   Facility: (*uint8)(0),
   Severity: (*uint8)(2),
   Priority: (*uint8)(2),
   Timestamp: (*time.Time)(<nil>),
   Hostname: (*string)(<nil>),
   Appname: (*string)(<nil>),
   ProcID: (*string)(<nil>),
   MsgID: (*string)(<nil>),
   Message: (*string)((len=3) "A\nB")
  },
  Version: (uint16) 1,
  StructuredData: (*map[string]map[string]string)(<nil>)
 }),
 Error: (error) <nil>
})
(*syslog.Result)({
 Message: (*rfc5424.SyslogMessage)({
  Base: (syslog.Base) {
   Facility: (*uint8)(0),
   Severity: (*uint8)(1),
   Priority: (*uint8)(1),
   Timestamp: (*time.Time)(<nil>),
   Hostname: (*string)(<nil>),
   Appname: (*string)(<nil>),
   ProcID: (*string)(<nil>),
   MsgID: (*string)(<nil>),
   Message: (*string)(<nil>)
  },
  Version: (uint16) 1,
  StructuredData: (*map[string]map[string]string)(<nil>)
 }),
 Error: (*errors.errorString)(parsing error [col 6])
})
(*syslog.Result)({
 Message: (*rfc5424.SyslogMessage)({
  Base: (syslog.Base) {
   Facility: (*uint8)(0),
   Severity: (*uint8)(1),
   Priority: (*uint8)(1),
   Timestamp: (*time.Time)(<nil>),
   Hostname: (*string)(<nil>),
   Appname: (*string)(<nil>),
   ProcID: (*string)(<nil>),
   MsgID: (*string)(<nil>),
   Message: (*string)((len=7) "A\nB\nC\nD")
  },
  Version: (uint16) 1,
  StructuredData: (*map[string]map[string]string)(<nil>)
 }),
 Error: (error) <nil>
})

Example (IntoChannelWithNUL)

messages := []string{
	"<2>1 - - - - - - A\x00B",
	"<1>1 -",
	"<1>1 - - - - - - A\x00B\x00C\x00D",
}

r, w := io.Pipe()

go func() {
	defer w.Close()

	for _, m := range messages {
		// Write message (containing trailers to be interpreted as part of the syslog MESSAGE)
		w.Write([]byte(m))
		// Write non-transparent frame boundary
		w.Write([]byte{0})
		// Wait a random amount of time
		time.Sleep(time.Millisecond * time.Duration(rand.Intn(100)))
	}
}()

results := make(chan *syslog.Result)
ln := func(x *syslog.Result) {
	// Emit the result
	results <- x
}

p := NewParser(syslog.WithListener(ln), WithTrailer(NUL))

go func() {
	defer close(results)
	defer r.Close()
	p.Parse(r)
}()

// Range over the results channel
for r := range results {
	output(r)
}

Output:

(*syslog.Result)({
 Message: (*rfc5424.SyslogMessage)({
  Base: (syslog.Base) {
   Facility: (*uint8)(0),
   Severity: (*uint8)(2),
   Priority: (*uint8)(2),
   Timestamp: (*time.Time)(<nil>),
   Hostname: (*string)(<nil>),
   Appname: (*string)(<nil>),
   ProcID: (*string)(<nil>),
   MsgID: (*string)(<nil>),
   Message: (*string)((len=3) "A\x00B")
  },
  Version: (uint16) 1,
  StructuredData: (*map[string]map[string]string)(<nil>)
 }),
 Error: (error) <nil>
})
(*syslog.Result)({
 Message: (syslog.Message) <nil>,
 Error: (*errors.errorString)(parsing error [col 6])
})
(*syslog.Result)({
 Message: (*rfc5424.SyslogMessage)({
  Base: (syslog.Base) {
   Facility: (*uint8)(0),
   Severity: (*uint8)(1),
   Priority: (*uint8)(1),
   Timestamp: (*time.Time)(<nil>),
   Hostname: (*string)(<nil>),
   Appname: (*string)(<nil>),
   ProcID: (*string)(<nil>),
   MsgID: (*string)(<nil>),
   Message: (*string)((len=7) "A\x00B\x00C\x00D")
  },
  Version: (uint16) 1,
  StructuredData: (*map[string]map[string]string)(<nil>)
 }),
 Error: (error) <nil>
})

Example (WithoutTrailerAtEnd)

results := []syslog.Result{}
acc := func(res *syslog.Result) {
	results = append(results, *res)
}
// Notice the message ends without trailer but we catch it anyway
r := strings.NewReader("<1>1 2003-10-11T22:14:15.003Z host.local - - - - mex")
NewParser(syslog.WithListener(acc)).Parse(r)
output(results)

Output:

([]syslog.Result) (len=1) {
 (syslog.Result) {
  Message: (syslog.Message) <nil>,
  Error: (*ragel.ReadingError)(unexpected EOF)
 }
}

Index

• func NewParser(options ...syslog.ParserOption) syslog.Parser
• func NewParserRFC3164(options ...syslog.ParserOption) syslog.Parser
• func WithTrailer(t TrailerType) syslog.ParserOption
• type TrailerType
  • func TrailerTypeFromString(s string) (TrailerType, error)
  • func (t TrailerType) MarshalText() ([]byte, error)
  • func (t TrailerType) String() string
  • func (t *TrailerType) UnmarshalTOML(data []byte) (err error)
  • func (t *TrailerType) UnmarshalText(data []byte) (err error)
  • func (t TrailerType) Value() (int, error)

Examples

• Package (BestEffortOnLastOne)
• Package (BestEffortWithoutTrailerAtEnd)
• Package (IntoChannelWithLF)
• Package (IntoChannelWithNUL)
• Package (WithoutTrailerAtEnd)

Functions

func NewParser

func NewParser(options ...syslog.ParserOption) syslog.Parser

NewParser returns a syslog.Parser suitable to parse syslog messages sent with non-transparent framing - ie. RFC 6587.

func NewParserRFC3164

func NewParserRFC3164(options ...syslog.ParserOption) syslog.Parser

func WithTrailer

func WithTrailer(t TrailerType) syslog.ParserOption

WithTrailer ... todo(leodido)

Types

type TrailerType

type TrailerType int

TrailerType is the king of supported trailers for non-transparent frames.

const (
	// LF is the line feed - ie., byte 10. Also the default one.
	LF TrailerType = iota
	// NUL is the nul byte - ie., byte 0.
	NUL
)

func TrailerTypeFromString

func TrailerTypeFromString(s string) (TrailerType, error)

TrailerTypeFromString returns a TrailerType given a string.

func (TrailerType) MarshalText

func (t TrailerType) MarshalText() ([]byte, error)

MarshalText implements encoding.TextMarshaler

func (TrailerType) String

func (t TrailerType) String() string

func (*TrailerType) UnmarshalTOML

func (t *TrailerType) UnmarshalTOML(data []byte) (err error)

UnmarshalTOML decodes trailer type from TOML data.

func (*TrailerType) UnmarshalText

func (t *TrailerType) UnmarshalText(data []byte) (err error)

UnmarshalText implements encoding.TextUnmarshaler

func (TrailerType) Value

func (t TrailerType) Value() (int, error)

Value returns the byte corresponding to the receiving TrailerType.