20219: make zle parameter HISTNO writeable

add history-pattern-search widget

1 files changed, 81 insertions, 0 deletions

diff --git a/Functions/Zle/history-pattern-search b/Functions/Zle/history-pattern-search
new file mode 100644
index 000000000..02f85a2fb
--- /dev/null
+++ b/Functions/Zle/history-pattern-search
@@ -0,0 +1,81 @@
+# Prompt for an search in the history for a pattern.
+# Patterns to search are standard zsh patterns, but may include
+# ^ at the start or $ at the end to anchor the pattern to the
+# start or end of the history entry respectively.
+#
+# To search backwards, create a widget history-pattern-search-backward:
+#   zle -N history-pattern-search-backward history-pattern-search
+# and to search forwards, create history-pattern-search-forward
+#   zle -N history-pattern-search-forward history-pattern-search
+
+# Use extended globbing by default.
+emulate -L zsh
+setopt extendedglob
+
+# Load required features.
+autoload -U read-from-minibuffer
+zmodload -i zsh/parameter
+
+local REPLY dir new
+integer i
+local -a found match mbegin mend
+
+# Decide if we are searching backwards or forwards.
+if [[ $WIDGET = *forward* ]]; then
+  dir="forw"
+else
+  dir="rev"
+fi
+
+# Read pattern.  Prompt could be made customisable.
+read-from-minibuffer "pat ($dir): "
+
+# Abort if bad status or nothing entered
+[[ $? -ne 0 || -z $REPLY ]] && return 0
+
+# Handle start-of-line anchor.
+if [[ $REPLY = \^* ]]; then
+  REPLY=$REPLY[2,-1]
+else
+  REPLY="*$REPLY"
+fi
+
+# Handle end-of-line anchor.
+if [[ $REPLY = *\$ ]]; then
+  REPLY=$REPLY[1,-2]
+else
+  REPLY="$REPLY*"
+fi
+
+# Search history for pattern.
+# As $history is an associative array we can get all matches.
+found=(${(kon)history[(R)$REPLY]})
+
+if [[ $dir = forw ]]; then
+  # Searching forward.  Look back through matches until we
+  # get back to the current history number.
+  for (( i = ${#found}; i >= 1; i-- )); do
+    (( $found[$i] <= HISTNO )) && break
+    new=$found[$i]
+  done
+else
+  # Searching backward.  Look forward through matches until we
+  # reach the current history number.
+  for (( i = 1; i <= ${#found}; i++ )); do
+    (( $found[$i] >= HISTNO )) && break
+    new=$found[$i]
+  done
+fi
+
+if [[ -n $new ]]; then
+  # Match found.  Move to line.
+  HISTNO=$new
+  if [[ $REPLY = *\* && $history[$new] = (#b)(${~REPLY[1,-2]})* ]]; then
+    # If not anchored to the end, move to the end of the pattern
+    # we were searching for.
+    CURSOR=$mend[1]
+  fi
+  return 0
+else
+  return 1
+fi