Option to omit CSV or TSV header line

--csv-omit-header and --tsv-omit-header will only print records,
skipping the first line with field names.  This is useful when output
will be passed to another command like `uniq` without needing to pipe
through `tail +2` first.

When using these options, `adifmt select -fields` is a good idea to
ensure fields match expectations.

adif/csv.go

@@ -29,6 +29,7 @@ type CSVIO struct {
 	LazyQuotes        bool
 	RequireFullRecord bool
 	TrimLeadingSpace  bool
+	OmitHeader        bool
 }
 
 func NewCSVIO() *CSVIO {
@@ -114,8 +115,10 @@ func (o *CSVIO) Write(l *Logfile, out io.Writer) error {
 	c.Comma = o.Comma
 	c.UseCRLF = o.CRLF
 	// CSV header row
-	if err := c.Write(order); err != nil {
-		return fmt.Errorf("writing CSV header to %s: %w", l, err)
+	if !o.OmitHeader {
+		if err := c.Write(order); err != nil {
+			return fmt.Errorf("writing CSV header to %s: %w", l, err)
+		}
 	}
 	row := make([]string, len(order))
 	for i, r := range l.Records {

adif/csv_test.go

@@ -165,3 +165,38 @@ Switzerland",",comma notes,,,"
 		}
 	}
 }
+
+func TestCSVOmitHeader(t *testing.T) {
+	l := NewLogfile()
+	l.Comment = "CSV ignores comments"
+	l.AddRecord(NewRecord(
+		Field{Name: "QSO_DATE", Value: "19901031", Type: TypeDate},
+		Field{Name: "TIME_ON", Value: "1234", Type: TypeTime},
+		Field{Name: "BAND", Value: "40M"},
+		Field{Name: "CALLSIGN", Value: "W1AW"},
+		Field{Name: "NAME", Value: "Hiram Percy Maxim", Type: TypeString},
+		Field{Name: "FREQ", Value: "7.054"},
+	)).AddRecord(NewRecord(
+		Field{Name: "QSO_DATE", Value: "20221224"},
+		Field{Name: "TIME_ON", Value: "095846"},
+		Field{Name: "BAND", Value: "1.25cm", Type: TypeEnumeration},
+		Field{Name: "CALLSIGN", Value: "N0P", Type: TypeString},
+		Field{Name: "NAME", Value: "Santa Claus"},
+		Field{Name: "NOTES_INTL", Value: `Þhrough the /❄\ bringing 🎁 \to the child\re\n`},
+	))
+	l.Records[1].SetComment("Record comment")
+	want := `19901031,1234,40M,W1AW,Hiram Percy Maxim,7.054,
+20221224,095846,1.25cm,N0P,Santa Claus,,Þhrough the /❄\ bringing 🎁 \to the child\re\n
+`
+	csv := NewCSVIO()
+	csv.OmitHeader = true
+	out := &strings.Builder{}
+	if err := csv.Write(l, out); err != nil {
+		t.Errorf("Write(%v) got error %v", l, err)
+	} else {
+		got := out.String()
+		if diff := cmp.Diff(want, got); diff != "" {
+			t.Errorf("Write(%v) had diff with expected:\n%s", l, diff)
+		}
+	}
+}

adif/tsv.go

@@ -26,6 +26,7 @@ type TSVIO struct {
 	CRLF               bool
 	EscapeSpecial      bool
 	IgnoreEmptyHeaders bool
+	OmitHeader         bool
 }
 
 func NewTSVIO() *TSVIO { return &TSVIO{} }
@@ -127,12 +128,14 @@ func (o *TSVIO) Write(l *Logfile, w io.Writer) error {
 		}
 		return nil
 	}
-	for i, h := range order {
-		if _, err := out.WriteString(o.escape(h)); err != nil {
-			return fmt.Errorf("writing TSV header: %w", err)
-		}
-		if err := writeDelim(i); err != nil {
-			return fmt.Errorf("writing TSV header: %w", err)
+	if !o.OmitHeader {
+		for i, h := range order {
+			if _, err := out.WriteString(o.escape(h)); err != nil {
+				return fmt.Errorf("writing TSV header: %w", err)
+			}
+			if err := writeDelim(i); err != nil {
+				return fmt.Errorf("writing TSV header: %w", err)
+			}
 		}
 	}
 	for _, r := range l.Records {

adif/tsv_test.go

@@ -183,3 +183,38 @@ func TestTSVEscapeSpecialCharacters(t *testing.T) {
 		}
 	}
 }
+
+func TestTSVOmitHeader(t *testing.T) {
+	l := NewLogfile()
+	l.Comment = "TSV ignores comments"
+	l.FieldOrder = []string{"QSO_DATE", "TIME_ON", "BAND", "CALL"}
+	l.AddRecord(NewRecord(
+		Field{Name: "TIME_ON", Value: "1234", Type: TypeTime},
+		Field{Name: "QSO_DATE", Value: "19901031", Type: TypeDate},
+		Field{Name: "NAME", Value: "Hiram Percy Maxim", Type: TypeString},
+		Field{Name: "BAND", Value: "40M"},
+		Field{Name: "FREQ", Value: "7.054"},
+		Field{Name: "CALL", Value: "W1AW"},
+	)).AddRecord(NewRecord(
+		Field{Name: "notes_intl", Value: "Þhrough the /❄\\ bringing 🎁 \\to the child\\re\\n"},
+		Field{Name: "qso_date", Value: "20221224"},
+		Field{Name: "call", Value: "N0P", Type: TypeString},
+		Field{Name: "time_on", Value: "095846"},
+		Field{Name: "band", Value: "1.25cm", Type: TypeEnumeration},
+		Field{Name: "name", Value: "Santa \"St. Nick\" Claus"},
+	))
+	l.Records[1].SetComment("Record comment")
+	want := "19901031\t1234\t40M\tW1AW\tHiram Percy Maxim\t7.054\t\n" +
+		"20221224\t095846\t1.25cm\tN0P\tSanta \"St. Nick\" Claus\t\tÞhrough the /❄\\ bringing 🎁 \\to the child\\re\\n\n"
+	tsv := NewTSVIO()
+	tsv.OmitHeader = true
+	out := &strings.Builder{}
+	if err := tsv.Write(l, out); err != nil {
+		t.Errorf("Write(%v) got error %v", l, err)
+	} else {
+		got := out.String()
+		if diff := cmp.Diff(want, got); diff != "" {
+			t.Errorf("Write(%v) had diff with expected:\n%s", l, diff)
+		}
+	}
+}

adifmt/formats.go

@@ -121,6 +121,7 @@ func (c csvConfig) AddFlags(fs *flag.FlagSet) {
 	fs.BoolVar(&c.io.RequireFullRecord, "csv-require-all-fields", false, "CSV files: error if fewer fields in a record than in header")
 	fs.BoolVar(&c.io.TrimLeadingSpace, "csv-trim-space", false, "CSV files: ignore leading space in fields")
 	fs.BoolVar(&c.io.CRLF, "csv-crlf", false, "CSV files: output MS Windows line endings")
+	fs.BoolVar(&c.io.OmitHeader, "csv-omit-header", false, "CSV files: don't output the header line")
 }
 
 type jsonConfig struct{ io *adif.JSONIO }
@@ -145,5 +146,6 @@ func (c tsvConfig) IO() adif.ReadWriter { return c.io }
 func (c tsvConfig) AddFlags(fs *flag.FlagSet) {
 	fs.BoolVar(&c.io.CRLF, "tsv-crlf", false, "TSV files: output MS Windows line endings")
 	fs.BoolVar(&c.io.EscapeSpecial, "tsv-escape-special", false, "TSV files: accept and produce \\t \\r \\n and \\\\ escapes in fields")
-	fs.BoolVar(&c.io.IgnoreEmptyHeaders, "tsv-ignore-empty-headers", false, "TSV files: do not return error if a TSV file has an empty header field")
+	fs.BoolVar(&c.io.IgnoreEmptyHeaders, "tsv-ignore-empty-headers", false, "TSV files: don't return error if a TSV file has an empty header field")
+	fs.BoolVar(&c.io.OmitHeader, "tsv-omit-header", false, "TSV files: don't output the header line")
 }