Version 0.5.0: pick, Zeilen auf dem Terminal wählen

CHANGELOG.md

@@ -7,6 +7,11 @@ folgen [Semantic Versioning](https://semver.org/lang/de/). Die Version steht in
 
 ## [Unveröffentlicht]
 
+## [0.5.0] - 2026-10-11
+
+### Hinzugefügt
+- `pick`: Tabelle auf dem Terminal durchblättern, filtern und eine oder mehrere Zeilen (`-m`) auswählen; die Auswahl geht als Tabelle auf die Standardausgabe. `-k` nimmt die Tasten aus einem String. Dazu `man/pick.man`, Beispiele in `testall.cmds` und Tests (auch mit Pseudo-Terminal).
+
 ## [0.4.0] - 2026-10-11
 
 ### Hinzugefügt

README.md

@@ -102,6 +102,21 @@ In der Vorlage: `<Spalte>` oder `<Spalte:20>` ist ein Feld (mit Breite), `[ Spei
 `[ Abbrechen ]` (oder Cancel, Abort, Quit) bricht ab, `<!date!>` fügt Befehlsausgabe ein. Kommt eine Spalte mehrfach
 vor, ist es ein Feld. Tab/Pfeile wechseln, Enter bestätigt, Esc bricht ab (Status 1, keine Ausgabe).
 
+## Zeilen auswählen: `pick`
+
+`pick` zeigt eine Tabelle auf dem Terminal, man scrollt, filtert und wählt eine oder mehrere Zeilen. Die Tabelle
+kommt von der Standardeingabe, die gewählten Zeilen gehen als Tabelle auf die Standardausgabe, also mitten in der Pipe:
+
+```
+pick < inventory                                  eine Zeile wählen
+pick -m < inventory | total Amount Value          mehrere (Leertaste markiert, a alle)
+column Item Description < inventory | pick -m | jointable - owners
+pick -m -k 'down space down enter' < inventory    Tasten aus einem String (Skripte, Tests)
+```
+
+Pfeile, Bild auf/ab, Pos1/Ende scrollen; `/` filtert (Enter behält den Filter, Esc löscht ihn); Enter wählt;
+Esc bricht ab (Status 1, keine Ausgabe). Ohne Markierung gilt die Zeile unter dem Cursor.
+
 ## Befehle
 
 | Gruppe | Befehle |
@@ -116,7 +131,7 @@ vor, ist es ein Feld. Tab/Pfeile wechseln, Enter bestätigt, Esc bricht ab (Stat
 | Text | `cap` `uppercase` `lowercase` `substitute` `trimblank` `padstring` `length` `filesize` `ascii` `chr` `word` `prompt` `not` `path` |
 | Umwandeln | `tabletolist` `listtotable` `listtosh` `tabletofix` `fixtotable` `tabletostruct` `tabletotbl` `tabletofact` `tabletorule` `tabletom4` `tabletosed` `translate` `uniondict` |
 | Datum, Namen | `julian` `gregorian` `computedate` `todaysdate` `soundex` `like` `hashkey` |
-| Berichte | `report` `reportwriter` `screen` `mask` `label` `letter` |
+| Berichte | `report` `reportwriter` `screen` `mask` `pick` `label` `letter` |
 | Terminal, Hilfe | `termput` `tset` `clear.rdb` `cursor` `menu` `rdb` `commands` `helpme` `whatis` `whatwill` `howmany` `man` |
 | Betrieb | `testall` `testsearch` `timesearch` `rmcore` `cpdir.rdb` |
 | Buchhaltung (/act) | `act` `chartdup` `foot` `adjust` `balance` `close` `consolidate` `getjournal` `fillform` `calculate` `tax` `cashflow` `calcpay` `w2` `bom` `explode` `sale` `invoice` `cstate` `update.inv` |

bin/pick

@@ -0,0 +1 @@
+/home/wkh/Development/Coherent/rdb/bin/rdb

demo/testall.cmds

@@ -265,3 +265,16 @@ bom ; cat bom
 ## update.inv: change the stock of one item, with record locking (INV names the table)
 cp inventory inv ; printf '7\n9\n\n' | INV=inv update.inv | tail -n +2
 grep '^7' inv
+
+## ===== Choosing rows on the terminal =====
+## pick shows a table, lets you scroll, filter (/) and mark rows (Space, -m), and writes the
+## chosen rows as a table, so it can sit in a pipe. It needs a terminal; -k feeds the keys instead.
+## Try it:  pick -m < inventory | total Amount Value
+## mark the 2nd and 5th row (down, space, down, down, space) and finish with enter
+pick -m -k 'down space down down space enter' < inventory
+## the same chosen rows go on into total
+pick -m -k 'down space down down space enter' < inventory | total Amount Value
+## filter with / (type, enter), then choose the row that is left
+pick -k '/clamps enter enter' < inventory
+## Esc cancels: nothing on stdout, exit status 1
+pick -k esc < inventory ; echo "status $?"

demo/testall.old

@@ -845,9 +845,9 @@ Item   Amount   Cost     Value     Description
 ## tabletom4 / tabletosed / tabletostruct were shown above
 ## ===== Help and the terminal =====
 $ rdb --version
-rdb 0.4.0
+rdb 0.5.0
 $ howmany
-135
+136
 $ whatis row
    row       - make a new table where rows match logical condition
    row       row 'column condition column-or-value ..' < table
@@ -1107,3 +1107,27 @@ Item Number: (or hit Return key to exit.) Item=7  Amount=5  Cost=175.00  Value=8
 Amount Amount: Item Number: (or hit Return key to exit.) 
 $ grep '^7' inv
 7	9	175.00	1575	scales  
+## ===== Choosing rows on the terminal =====
+## pick shows a table, lets you scroll, filter (/) and mark rows (Space, -m), and writes the
+## chosen rows as a table, so it can sit in a pipe. It needs a terminal; -k feeds the keys instead.
+## Try it:  pick -m < inventory | total Amount Value
+## mark the 2nd and 5th row (down, space, down, down, space) and finish with enter
+$ pick -m -k 'down space down down space enter' < inventory
+Item	Amount	Cost	Value	Description
+----	------	----	-----	-----------
+2	100	0.50	50.00	test tubes
+5	99	2.45	242.55	cleaning cloth
+## the same chosen rows go on into total
+$ pick -m -k 'down space down down space enter' < inventory | total Amount Value
+Item	Amount	Cost	Value	Description
+----	------	----	-----	-----------
+	199		292.55	
+## filter with / (type, enter), then choose the row that is left
+$ pick -k '/clamps enter enter' < inventory
+Item	Amount	Cost	Value	Description
+----	------	----	-----	-----------
+3	6	8.00	48.00	clamps
+## Esc cancels: nothing on stdout, exit status 1
+$ pick -k esc < inventory ; echo "status $?"
+pick: nothing chosen
+status 1

lib/rdb/cmd/pick.rb

@@ -0,0 +1,218 @@
+# frozen_string_literal: true
+
+require 'io/console'
+
+# pick -- look at a table on the terminal, scroll through it and choose one or
+# several rows.  The table comes in on the standard input, the chosen rows go
+# out on the standard output as a table, so it sits in the middle of a pipe:
+#   column Item Description < inventory | pick -m | total Item
+# The keys are read from /dev/tty (or, for scripts and tests, from -k).
+module Rdb
+  module Pick
+    KEYS = {
+      'up' => "\e[A", 'down' => "\e[B", 'pgup' => "\e[5~", 'pgdn' => "\e[6~",
+      'home' => "\e[H", 'end' => "\e[F", 'enter' => "\r", 'space' => ' ',
+      'esc' => "\e", 'backspace' => "\x7f"
+    }.freeze
+
+    # The state of one session: which rows are shown, where the cursor is,
+    # which rows are marked.  Knows nothing about the terminal.
+    class Session
+      attr_reader :head, :rows, :cursor, :top, :filter, :marked
+
+      def initialize(head, rows, multi: false)
+        @head = head
+        @rows = rows
+        @multi = multi
+        @marked = []
+        @filter = +''
+        @typing = false
+        @cursor = 0
+        @top = 0
+        @height = 20
+        @width = 80
+        refilter
+      end
+
+      def resize(height, width)
+        @height = [height, 1].max
+        @width = [width, 20].max
+        scroll
+      end
+
+      def typing? = @typing
+
+      # Indices (into rows) of the rows that pass the filter.
+      def visible = @visible
+
+      def current = @visible[@cursor]
+
+      # Rows to hand on: the marked ones, else the row under the cursor.
+      def selected
+        idx = @marked.empty? ? [current].compact : @marked.sort
+        idx.map { |i| @rows[i] }
+      end
+
+      # Returns :accept or :cancel when the session is over.
+      def feed(key)
+        @typing ? type(key) : browse(key)
+      end
+
+      def render
+        widths = @head.each_index.map { |i| ([@head[i]] + @rows.map { |r| r[i].to_s }).map(&:size).max }
+        line = ->(cells) { cells.each_with_index.map { |c, i| c.to_s.ljust(widths[i]) }.join('  ').rstrip }
+        out = +"\e[?25l\e[H"
+        out << "\e[K  \e[1m#{fit(line.(@head))}\e[0m\r\n"
+        out << "\e[K  #{fit(widths.map { |w| '-' * w }.join('  '))}\r\n"
+        @height.times do |n|
+          pos = @top + n
+          i = @visible[pos]
+          out << "\e[K"
+          if i
+            text = "#{@marked.include?(i) ? '*' : ' '} #{fit(line.(@rows[i]))}"
+            out << (pos == @cursor ? "\e[7m#{text}\e[0m" : text)
+          end
+          out << "\r\n"
+        end
+        out << "\e[K#{status}"
+        out
+      end
+
+      private
+
+      def fit(text) = text[0, @width - 2]
+
+      def status
+        keys = @typing ? 'type to filter  Enter keep  Esc clear' : "Enter ok#{'  Space mark  a all' if @multi}  / filter  Esc cancel"
+        filter = @filter.empty? && !@typing ? '' : "  /#{@filter}#{'_' if @typing}"
+        "\e[7m #{@visible.empty? ? 0 : @cursor + 1}/#{@visible.size} of #{@rows.size}" \
+          "#{"  marked #{@marked.size}" if @multi}#{filter}  #{keys} \e[0m"
+      end
+
+      def browse(key)
+        case key
+        when "\e[A" then move(-1)
+        when "\e[B" then move(1)
+        when "\e[5~" then move(-@height)
+        when "\e[6~" then move(@height)
+        when "\e[H", "\e[1~", "\eOH" then move(-@visible.size)
+        when "\e[F", "\e[4~", "\eOF" then move(@visible.size)
+        when "\r", "\n" then return selected.empty? ? :cancel : :accept
+        when ' ' then toggle
+        when 'a' then mark_all if @multi
+        when '/' then @typing = true
+        when "\x03", "\e", 'q' then return :cancel
+        end
+        nil
+      end
+
+      def type(key)
+        case key
+        when "\r", "\n" then @typing = false
+        when "\e" then @filter.clear; @typing = false; refilter
+        when "\x03" then return :cancel
+        when "\x7f", "\b" then @filter.chop!; refilter
+        else
+          if key.size == 1 && key.ord >= 32
+            @filter << key
+            refilter
+          end
+        end
+        nil
+      end
+
+      def refilter
+        needle = @filter.downcase
+        @visible = @rows.each_index.select { |i| needle.empty? || @rows[i].join("\t").downcase.include?(needle) }
+        @cursor = [@cursor, [@visible.size - 1, 0].max].min
+        scroll
+      end
+
+      def move(delta)
+        @cursor = (@cursor + delta).clamp(0, [@visible.size - 1, 0].max)
+        scroll
+      end
+
+      def scroll
+        @top = @cursor if @cursor < @top
+        @top = @cursor - @height + 1 if @cursor >= @top + @height
+        @top = 0 if @top.negative?
+      end
+
+      def toggle
+        return unless @multi && current
+
+        @marked.include?(current) ? @marked.delete(current) : @marked << current
+        move(1)
+      end
+
+      def mark_all
+        all = @visible.all? { |i| @marked.include?(i) }
+        all ? @marked -= @visible : @marked |= @visible
+      end
+    end
+
+    def self.run(session, tty)
+      tty.raw do
+        tty.write "\e[?1049h"
+        begin
+          loop do
+            rows, cols = tty.winsize
+            session.resize((rows.zero? ? 24 : rows) - 3, cols.zero? ? 80 : cols)
+            tty.write session.render
+            key = begin
+              Rdb::Mask.read_key(tty)
+            rescue EOFError
+              "\x03"
+            end
+            result = session.feed(key)
+            return result if result
+          end
+        ensure
+          tty.write "\e[?25h\e[?1049l"
+        end
+      end
+    end
+
+    # Words of a -k script: a name from KEYS, or else every character is one key.
+    def self.script(words)
+      words.split.flat_map { |w| KEYS.key?(w) ? [KEYS[w]] : w.chars }
+    end
+  end
+end
+
+Rdb.register('pick', 'Scroll through a table and choose one or more rows', 'pick [-m] [-k keys] < table > chosenrows') do |args|
+  multi = !args.delete('-m').nil?
+  keys = nil
+  if (i = args.index('-k'))
+    keys = args[i + 1] or die 'usage: pick [-m] [-k keys] < table'
+    args.slice!(i, 2)
+  end
+  die 'usage: pick [-m] [-k "down space enter"] < table > chosenrows' unless args.empty?
+
+  t = table_in
+  die 'pick: the table is empty' if t.rows.empty?
+  session = Rdb::Pick::Session.new(t.head, t.rows, multi: multi)
+
+  result = nil
+  if keys
+    session.resize(21, 80)
+    Rdb::Pick.script(keys).each do |k|
+      result = session.feed(k)
+      break if result
+    end
+  else
+    tty = begin
+      File.open('/dev/tty', 'r+')
+    rescue SystemCallError
+      die 'no terminal available (pick takes its keys from /dev/tty; see -k)'
+    end
+    result = Rdb::Pick.run(session, tty)
+    tty.close
+  end
+  unless result == :accept
+    warn 'pick: nothing chosen'
+    exit 1
+  end
+  Rdb::Table.new(t.head, session.selected).write
+end

lib/rdb/version.rb

@@ -1,5 +1,5 @@
 # frozen_string_literal: true
 
 module Rdb
-  VERSION = '0.4.0'
+  VERSION = '0.5.0'
 end

man/pick.man

@@ -0,0 +1,83 @@
+.TH pick "" "" "/rdb Command"
+.PC "Scroll through a table and choose one or more rows"
+\fBpick \fB[ -m ] [ -k \fIkeys\fB ] < \fItable \fB> \fIchosenrows\fR
+.PP
+.II "pick^choose rows"
+.II "table^scroll"
+.I "(Ruby re-creation only; the original /rdb has no such command.)"
+.PP
+The command
+.B pick
+shows
+.I table
+on the terminal, lets the user scroll through it, and writes the rows
+that were chosen as a table on the standard output.
+It therefore fits into the middle of a pipe:
+.DM
+column Item Description < inventory | pick -m | jointable - owners
+pick -m < inventory | total Amount Value
+.DE
+.PP
+The table is read from the standard input;
+the keys are read from the terminal (\fB/dev/tty\fR).
+A list is read like a table, and the output is always a table.
+The head and the dash line stay at the top while the rows scroll.
+.SH Keys
+.nf
+Up, Down             move the cursor one row
+PgUp, PgDn           move a page
+Home, End            first or last row
+Enter                choose and finish
+Space                mark the row, move down (with -m)
+a                    mark all shown rows; again, unmark them (with -m)
+/                    filter: type text, shown rows must contain it
+                       (Enter keeps the filter, Esc clears it)
+Esc, q, Ctrl-C       cancel
+.fi
+.PP
+.B pick
+writes the marked rows in table order.
+If no row is marked, it writes the row under the cursor.
+Marks stay when a filter hides the row.
+If the user cancels, or the filter leaves no row to choose,
+.B pick
+writes nothing and exits with status 1.
+.SH Options
+.IP \fB-m\fR 0.5i
+Allow several rows: Space marks, \fBa\fR marks all.
+Without it, Enter chooses the row under the cursor.
+.IP "\fB-k\fR \fIkeys\fR"
+Take the keys from this string instead of the terminal.
+Words are key names:
+.BR up ,
+.BR down ,
+.BR pgup ,
+.BR pgdn ,
+.BR home ,
+.BR end ,
+.BR enter ,
+.BR space ,
+.BR esc ,
+.BR backspace ;
+any other word is typed character by character.
+This is for scripts, demonstrations and tests.
+.SH Example
+.DM
+pick -m -k 'down space down down space enter' < inventory
+.DE
+.PP
+marks the second and the fifth row and prints:
+.DM
+Item   Amount   Cost   Value    Description
+----   ------   ----   ------   --------------
+2      100      0.50   50.00    test tubes
+5      99       2.45   242.55   cleaning cloth
+.DE
+.SH "See Also"
+.B
+display,
+mask,
+row,
+search
+.R
+.SO rdb

test/rdb_test.rb

@@ -618,3 +618,108 @@ class MaskTest < RdbCase
     assert_equal '', table
   end
 end
+
+class PickTest < RdbCase
+  def session(multi: true, height: 3)
+    t = Rdb::Table.read(File.open(File.join(DEMO, 'inventory')))
+    Rdb::Pick::Session.new(t.head, t.rows, multi: multi).tap { |x| x.resize(height, 80) }
+  end
+
+  def keys(sess, words) = Rdb::Pick.script(words).map { |k| sess.feed(k) }.compact.last
+
+  def test_mark_and_select
+    s = session
+    assert_equal :accept, keys(s, 'down space down down space enter')
+    assert_equal %w[2 5], s.selected.map(&:first)
+  end
+
+  def test_single_mode_takes_the_cursor_row_and_ignores_space
+    s = session(multi: false)
+    assert_equal :accept, keys(s, 'down down space enter')
+    assert_equal %w[3], s.selected.map(&:first)
+  end
+
+  def test_scrolling_keeps_the_cursor_in_view
+    s = session(height: 3)
+    keys(s, 'down down down down')
+    assert_equal [4, 2], [s.cursor, s.top]
+    keys(s, 'end')
+    assert_equal [6, 4], [s.cursor, s.top]
+    keys(s, 'pgup')
+    assert_equal 3, s.cursor
+    keys(s, 'home')
+    assert_equal [0, 0], [s.cursor, s.top]
+  end
+
+  def test_filter_and_clear
+    s = session
+    keys(s, '/clam')
+    assert_predicate s, :typing?
+    keys(s, 'enter')
+    assert_equal [2], s.visible
+    keys(s, '/ esc')
+    assert_equal 7, s.visible.size
+  end
+
+  def test_marks_survive_a_filter_and_a_all_toggles
+    s = session
+    keys(s, 'space /scales enter')
+    assert_equal [0], s.marked
+    keys(s, 'a')
+    assert_equal [0, 6], s.marked.sort
+    keys(s, 'a')
+    assert_equal [0], s.marked
+  end
+
+  def test_cancel_and_empty_choice
+    assert_equal :cancel, keys(session, 'esc')
+    assert_equal :cancel, keys(session, '/zzz enter enter')
+  end
+
+  def test_command_with_keys_script_is_a_filter
+    out = rdb('pick', '-m', '-k', 'down space down down space enter', file: 'inventory')
+    assert_equal %w[2 5], data(out).map(&:first)
+    assert_equal '292.55', data(rdb('total', 'Value', stdin: out)).first[3]
+  end
+
+  def test_command_cancelled_exits_1_with_no_output
+    out, _err, st = run3('pick', '-k', 'esc', stdin: File.read(File.join(@dir, 'inventory')))
+    refute st.success?
+    assert_equal '', out
+  end
+
+  def test_command_reads_a_list
+    out = rdb('pick', '-k', 'down enter', stdin: rdb('tabletolist', file: 'owners'))
+    assert_equal [%w[3 bob]], data(out)
+  end
+
+  def run_on_pty(*key_strokes)
+    out = File.join(@dir, 'pick.out')
+    result = nil
+    PTY.spawn({ 'PATH' => "#{BIN}:#{ENV['PATH']}" }, 'sh', '-c', "cd #{@dir} && pick -m < inventory > pick.out") do |r, w, pid|
+      sleep 0.5
+      key_strokes.each do |k|
+        w.write k
+        sleep 0.1
+        r.read_nonblock(65_536) rescue nil
+      end
+      sleep 0.3
+      r.read_nonblock(65_536) rescue nil
+      _, st = Process.wait2(pid)
+      result = [File.exist?(out) ? File.read(out) : '', st.exitstatus]
+    end
+    result
+  end
+
+  def test_pick_on_a_terminal
+    table, status = run_on_pty("\e[B", ' ', "\e[B", ' ', "\r")
+    assert_equal 0, status
+    assert_equal %w[2 4], data(table).map(&:first)
+  end
+
+  def test_pick_on_a_terminal_cancel
+    table, status = run_on_pty("\e[B", "\e")
+    assert_equal 1, status
+    assert_equal '', table
+  end
+end