Script-friendly CLI output, and keep record list rows on one line

-o id and -o field=NAME,... print just the IDs or chosen fields; -q on
show and list prints the IDs. jarl record list shortens data too long
for the terminal (--wide shows it in full).

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

cmd/jarl/complete.go

@@ -24,7 +24,7 @@ const completeTimeout = 3 * time.Second
 // setupCompletion adds value completion to the command tree.
 func setupCompletion(root *cobra.Command) {
 	root.RegisterFlagCompletionFunc("server", completeServers(true))
-	root.RegisterFlagCompletionFunc("output", cobra.FixedCompletions([]string{"table", "json", "yaml"}, cobra.ShellCompDirectiveNoFileComp))
+	root.RegisterFlagCompletionFunc("output", cobra.FixedCompletions([]string{"table", "json", "yaml", "id", "field="}, cobra.ShellCompDirectiveNoFileComp|cobra.ShellCompDirectiveNoSpace))
 	var walk func(c *cobra.Command)
 	walk = func(c *cobra.Command) {
 		for _, name := range []string{"view", "user", "zone"} {

cmd/jarl/main.go

@@ -3,6 +3,7 @@
 package main
 
 import (
+	"bytes"
 	"context"
 	"encoding/json"
 	"errors"
@@ -11,6 +12,7 @@ import (
 	"net/url"
 	"os"
 	"path/filepath"
+	"slices"
 	"strconv"
 	"strings"
 	"sync"
@@ -237,10 +239,10 @@ Exit codes: 0 ok, 1 error, 3 not authenticated or not allowed, 4 not found,
 	pf.Int64VarP(&flagChangeset, "changeset", "C", 0, "stage changes into this changeset instead of applying them (env JARL_CHANGESET)")
 	pf.BoolVarP(&flagDryRun, "dry-run", "n", false, "validate and show the changes without applying them")
 	pf.BoolVar(&flagForce, "force", false, "overwrite BIND files that were changed outside Jarl")
-	pf.StringVarP(&flagOutput, "output", "o", "table", "output format: table, json or yaml")
+	pf.StringVarP(&flagOutput, "output", "o", "table", "output format: table, json, yaml, id (just the IDs) or field=NAME[,NAME...] (just those fields, e.g. field=view or field=soa.serial)")
 	pf.BoolVar(&flagInsecure, "insecure", false, "don't verify the server's TLS certificate")
 	pf.StringVar(&flagCACert, "ca-cert", "", "PEM file with a CA to trust for the server's certificate")
-	pf.BoolVarP(&flagQuiet, "quiet", "q", false, "only print errors (and IDs where useful)")
+	pf.BoolVarP(&flagQuiet, "quiet", "q", false, "only print errors and IDs (with show and list: just the IDs, like -o id)")
 	root.AddGroup(&cobra.Group{ID: "dns", Title: "DNS commands:"}, &cobra.Group{ID: "changes", Title: "Changes:"}, &cobra.Group{ID: "admin", Title: "Administration:"})
 	add := func(group string, cmds ...*cobra.Command) {
 		for _, c := range cmds {
@@ -262,7 +264,15 @@ func ctx() context.Context { return context.Background() }
 // ---- output
 
 func output(v any, table func(w io.Writer)) error {
-	switch flagOutput {
+	format := flagOutput
+	quietIDs := flagQuiet && (format == "table" || format == "")
+	if quietIDs {
+		format = "id"
+	}
+	if fieldFormat(format) {
+		return outputFields(v, format, quietIDs)
+	}
+	switch format {
 	case "json":
 		enc := json.NewEncoder(os.Stdout)
 		enc.SetIndent("", "  ")
@@ -286,7 +296,79 @@ func output(v any, table func(w io.Writer)) error {
 		table(tw)
 		return tw.Flush()
 	}
-	return fmt.Errorf("unknown output format %q (use table, json or yaml)", flagOutput)
+	return fmt.Errorf("unknown output format %q (use table, json, yaml, id or field=NAME)", flagOutput)
+}
+
+// outputFields prints fields of each object (or of the one object), one
+// line per object with the fields separated by tabs, for scripts:
+// "id" prints the IDs, "field=view,soa.serial" those fields. Names are the
+// JSON field names (see -o json); a dot reaches into nested objects. A
+// field an object doesn't have prints as empty (the API leaves out empty
+// fields).
+func outputFields(v any, format string, quiet bool) error {
+	fields := []string{"id"}
+	if f, ok := strings.CutPrefix(format, "field="); ok {
+		fields = strings.Split(f, ",")
+	}
+	b, err := json.Marshal(v)
+	if err != nil {
+		return err
+	}
+	dec := json.NewDecoder(bytes.NewReader(b))
+	dec.UseNumber()
+	var x any
+	if err := dec.Decode(&x); err != nil {
+		return err
+	}
+	items, ok := x.([]any)
+	if !ok {
+		items = []any{x}
+	}
+	if quiet && !slices.ContainsFunc(items, func(it any) bool { _, ok := lookupField(it, "id"); return ok }) {
+		return nil // -q on something without IDs: only errors
+	}
+	var out strings.Builder
+	for _, it := range items {
+		var vals []string
+		for _, f := range fields {
+			val, _ := lookupField(it, strings.TrimSpace(f))
+			vals = append(vals, fieldText(val))
+		}
+		out.WriteString(strings.Join(vals, "\t") + "\n")
+	}
+	_, err = io.WriteString(os.Stdout, out.String())
+	return err
+}
+
+// fieldFormat reports whether an -o format prints fields (id, field=...).
+func fieldFormat(format string) bool {
+	return format == "id" || strings.HasPrefix(format, "field=")
+}
+
+func lookupField(v any, path string) (any, bool) {
+	for _, part := range strings.Split(path, ".") {
+		m, ok := v.(map[string]any)
+		if !ok {
+			return nil, false
+		}
+		if v, ok = m[part]; !ok {
+			return nil, false
+		}
+	}
+	return v, true
+}
+
+func fieldText(v any) string {
+	switch x := v.(type) {
+	case nil:
+		return ""
+	case string:
+		return x
+	case json.Number, bool:
+		return fmt.Sprint(x)
+	}
+	b, _ := json.Marshal(v)
+	return string(b)
 }
 
 func dot(name string) string {
@@ -391,6 +473,14 @@ func report(resp *api.MutationResponse) error {
 	if flagOutput == "json" || flagOutput == "yaml" {
 		return output(resp, nil)
 	}
+	if fieldFormat(flagOutput) {
+		// The changed object, if the response has it ("jarl record add
+		// ... -o id" prints the new record's ID).
+		if len(resp.Object) > 0 {
+			return outputFields(resp.Object, flagOutput, false)
+		}
+		return outputFields(resp, flagOutput, false)
+	}
 	w := os.Stdout
 	r := client.ParseResult(resp.Result)
 	switch {

cmd/jarl/main_test.go

@@ -5,6 +5,7 @@ import (
 	"io"
 	"net/http"
 	"net/http/httptest"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -190,3 +191,44 @@ func TestListQueries(t *testing.T) {
 		}
 	}
 }
+
+func TestOutputFields(t *testing.T) {
+	capture := func(f func() error) string {
+		t.Helper()
+		r, w, _ := os.Pipe()
+		old := os.Stdout
+		os.Stdout = w
+		err := f()
+		os.Stdout = old
+		w.Close()
+		b, _ := io.ReadAll(r)
+		if err != nil {
+			t.Fatal(err)
+		}
+		return string(b)
+	}
+	zones := []map[string]any{
+		{"id": 12, "name": "adbraun.lol.", "view": "external", "soa": map[string]any{"serial": 2026100901}},
+		{"id": 3, "name": "lab.adbraun.lol.", "soa": map[string]any{"serial": 7}},
+	}
+	defer func(o string, q bool) { flagOutput, flagQuiet = o, q }(flagOutput, flagQuiet)
+	for _, tc := range []struct {
+		format string
+		quiet  bool
+		v      any
+		want   string
+	}{
+		{"id", false, zones, "12\n3\n"},
+		{"id", false, zones[0], "12\n"},
+		{"field=name,view,soa.serial", false, zones, "adbraun.lol.\texternal\t2026100901\nlab.adbraun.lol.\t\t7\n"},
+		{"field=soa", false, zones[1], "{\"serial\":7}\n"},
+		{"table", true, zones, "12\n3\n"},
+		{"table", true, map[string]any{"status": "ok"}, ""}, // -q without IDs: nothing
+	} {
+		flagOutput, flagQuiet = tc.format, tc.quiet
+		got := capture(func() error { return output(tc.v, func(io.Writer) { t.Error("table printed") }) })
+		if got != tc.want {
+			t.Errorf("-o %s (quiet %v) = %q, want %q", tc.format, tc.quiet, got, tc.want)
+		}
+	}
+}

cmd/jarl/zones.go

@@ -3,12 +3,14 @@ package main
 import (
 	"encoding/json"
 	"fmt"
+	"golang.org/x/term"
 	"io"
 	"net/netip"
 	"net/url"
 	"os"
 	"strconv"
 	"strings"
+	"unicode/utf8"
 
 	"github.com/spf13/cobra"
 
@@ -407,7 +409,7 @@ func jsonUnmarshal(b []byte, v any) error { return json.Unmarshal(b, v) }
 func recordCmd() *cobra.Command {
 	cmd := &cobra.Command{Use: "record", Aliases: []string{"records", "rr"}, Short: "Manage records in primary zones"}
 	var view, name, typ, search, comment, ttlArg string
-	var ptr, missingOK, yes, onlyDisabled bool
+	var ptr, missingOK, yes, onlyDisabled, wide bool
 	var id int64
 
 	list := &cobra.Command{
@@ -431,7 +433,7 @@ func recordCmd() *cobra.Command {
 				return err
 			}
 			return output(recs, func(w io.Writer) {
-				fmt.Fprintln(w, "ID\tNAME\tTTL\tTYPE\tDATA\tCOMMENT")
+				rows := [][]string{{"ID", "NAME", "TTL", "TYPE", "DATA", "COMMENT"}}
 				for _, r := range recs {
 					ttl := fmt.Sprint(r.EffectiveTTL)
 					if r.TTL == nil {
@@ -441,7 +443,13 @@ func recordCmd() *cobra.Command {
 					if r.Disabled {
 						comment = strings.TrimSpace("[disabled] " + comment)
 					}
-					fmt.Fprintf(w, "%d\t%s\t%s\t%s\t%s\t%s\n", r.ID, r.RelativeName, ttl, r.Type, r.Data, comment)
+					rows = append(rows, []string{fmt.Sprint(r.ID), r.RelativeName, ttl, r.Type, r.Data, comment})
+				}
+				if !wide {
+					fitColumn(rows, 4)
+				}
+				for _, row := range rows {
+					fmt.Fprintln(w, strings.Join(row, "\t"))
 				}
 			})
 		},
@@ -451,6 +459,7 @@ func recordCmd() *cobra.Command {
 	list.Flags().StringVarP(&typ, "type", "t", "", "only this type")
 	list.Flags().StringVar(&search, "search", "", "only records whose name, data or comment contains this")
 	list.Flags().BoolVar(&onlyDisabled, "disabled", false, "only disabled records")
+	list.Flags().BoolVarP(&wide, "wide", "w", false, "show long data in full (on a terminal it is shortened to fit)")
 
 	add := &cobra.Command{
 		Use:   "add ZONE NAME TYPE DATA...",
@@ -724,3 +733,39 @@ func setTTL(body map[string]any, ttl string) error {
 	}
 	return nil
 }
+
+// fitColumn shortens column col of a table (header row first) so that the
+// rows fit the terminal: the table pads every row to its longest cell, so
+// one long TXT record would make every row wrap. Nothing is shortened when
+// standard output isn't a terminal.
+func fitColumn(rows [][]string, col int) {
+	fd := int(os.Stdout.Fd())
+	if !term.IsTerminal(fd) {
+		return
+	}
+	width, _, err := term.GetSize(fd)
+	if err != nil || width <= 0 {
+		return
+	}
+	widths := make([]int, len(rows[0]))
+	for _, row := range rows {
+		for i, c := range row {
+			widths[i] = max(widths[i], utf8.RuneCountInString(c))
+		}
+	}
+	used := 0
+	for i, w := range widths {
+		if i != col {
+			used += w + 2 // the table's padding
+		}
+	}
+	if col == len(widths)-1 {
+		used -= 2
+	}
+	limit := max(width-used-2, 24)
+	for _, row := range rows[1:] {
+		if r := []rune(row[col]); len(r) > limit {
+			row[col] = string(r[:limit-1]) + "…"
+		}
+	}
+}