Script created with the help of o3-mini, it searches git repo for a commit with specified text, allows to find change also in files deleted/moved long times ago. Example use: `find_commit_diff.sh --search overrideAamCriticalParameters` it will also print progress and allows to do reverse search - default is search from newest commits to oldest.

find_commit_diff.sh

#!/bin/bash
# find_commit_diff.sh
# Usage: ./find_commit_diff.sh --search <string> [--reverse]
#   --search   The search string (e.g. "overrideAamCriticalParameters")
#   --reverse  Process commits from oldest to newest (optional)

# If no parameters are provided, show help
if [ $# -eq 0 ]; then
  echo "Usage: $0 --search <string> [--reverse]"
  exit 1
fi

SEARCH_STRING=""
REVERSE_FLAG=""

# Parse parameters
while [[ $# -gt 0 ]]; do
  case "$1" in
    --search)
      shift
      if [ -z "$1" ]; then
        echo "Error: --search requires an argument."
        exit 1
      fi
      SEARCH_STRING="$1"
      shift
      ;;
    --reverse)
      REVERSE_FLAG="--reverse"
      shift
      ;;
    --help|-h)
      echo "Usage: $0 --search <string> [--reverse]"
      exit 0
      ;;
    *)
      echo "Unknown parameter: $1"
      echo "Usage: $0 --search <string> [--reverse]"
      exit 1
      ;;
  esac
done

if [ -z "$SEARCH_STRING" ]; then
  echo "Error: search string not provided."
  echo "Usage: $0 --search <string> [--reverse]"
  exit 1
fi

# Determine the revision list command based on the reverse flag.
ITERATION_CMD="git rev-list --all $REVERSE_FLAG"

# Count total commits for progress calculation
TOTAL_COMMITS=$(git rev-list --all $REVERSE_FLAG | wc -l)
PROCESSED=0
LAST_UPDATE=0

# Iterate through commits using process substitution to avoid subshell issues.
while read -r commit; do
  PROCESSED=$((PROCESSED+1))
  CURRENT_TIME=$(date +%s)
  # Update progress every 3 seconds.
  if [ $((CURRENT_TIME - LAST_UPDATE)) -ge 3 ]; then
    # Calculate percentage (using awk for float arithmetic)
    PERCENT=$(awk "BEGIN {printf \"%.2f\", ($PROCESSED/$TOTAL_COMMITS)*100}")
    # Get the commit date (using git show for that commit)
    COMMIT_DATE=$(git show -s --format=%ci "$commit")
    # Print progress on one line (carriage return returns to start of line)
    echo -ne "\rProgress: $PERCENT% - Last Commit Date: $COMMIT_DATE"
    LAST_UPDATE=$CURRENT_TIME
  fi

  # Get added lines from the diff that contain the search string
  MATCHES=$(git show "$commit" --unified=0 | grep '^+' | grep -v '^+++' | grep "$SEARCH_STRING")
  if [ -n "$MATCHES" ]; then
    echo -e "\nCommit: $commit"
    echo "$MATCHES"
    echo "--------------------------------"
  fi

done < <(git rev-list --all $REVERSE_FLAG)

# Clear progress line at end
echo -ne "\r"
echo "Done scanning $TOTAL_COMMITS commits."