Feature/implement tail with search and highlight

README.md

@@ -1,2 +1,116 @@
-# search-tail
-Search Tail - A tail-like CLI tool with support for search and keyword highlighting
+# Search-Tail
+
+Search-Tail (`stail`) is a command-line tool similar to `tail`, with added search functionality and keyword highlighting.
+
+## Features
+
+- Displays the last `n` lines of a file (default: 50).
+- Highlight search term matches in green.
+- Predefined keywords like "ERROR", "CRITICAL", "WARNING", etc., are also highlighted.
+  - This could be configured to suit your needs.
+- Navigate through matches using `n` (next) and `p` (previous).
+- Reload file to view newly added lines with `r`.
+- Search for another keyword with `s`.
+- Quit with `q`.
+
+## Installation
+
+### Using `install.sh`
+
+1. Clone the repository:
+
+   ```bash
+   git clone https://github.com/febinjoy/search-tail.git
+   ```
+
+2. Navigate to the repository directory:
+
+   ```bash
+   cd search-tail
+   ```
+
+3. Make the `install.sh` script executable:
+
+   ```bash
+   chmod +x install.sh
+   ```
+
+4. Run the `install.sh` script:
+
+   ```bash
+   ./install.sh
+   ```
+
+### Manual Steps
+
+You can also manually add the alias to your `.bashrc` or `.zshrc`
+
+1. Clone the repository:
+
+   ```bash
+   git clone <repository-url>
+   ```
+
+2. Add the following alias to your `.bashrc` or `.zshrc`:
+
+   ```bash
+   alias stail='python3 <Path of Search-Tail>/search_tail/__main__.py "$@"'
+   ```
+
+3. Source your `.bashrc` or `.zshrc` file:
+
+   ```bash
+   source ~/.bashrc
+   ```
+
+   or
+
+   ```bash
+   source ~/.zshrc
+   ```
+
+## Usage
+
+```bash
+stail <file_name> [-n <number_of_lines>] [-s <search_term>]
+```
+
+- `<file_name>`: The name of the file to display.
+- `-n <number_of_lines>`: Display the last n lines of the file (default: 50).
+- `-s <search_term>`: Search for the specified term and highlight matches.
+
+## Navigation Commands
+
+- `n`: Go to the next match.
+- `p`: Go to the previous match.
+- `r`: Reload the file to view newly added lines.
+- `s`: Search for another keyword.
+- `q`: Quit.
+
+## Example
+
+### When search keyword is not provided.
+
+```bash
+stail -n 100 -my_log_file.log
+```
+This displays the last 100 lines of `my_log_file.log`. Since we have not specified any search keyword, only the predefined keywords like "ERROR", "CRITICAL", "WARNING" etc are highlighted in respective colors.
+
+![image](https://github.com/user-attachments/assets/0814e250-974c-4245-9f77-640a72c80563)
+
+
+### When search keyword is provided.
+
+```bash
+stail -n 100 -s database my_log_file.log
+```
+
+This displays the last 100 lines of `my_log_file.log` and highlights occurrences of the word `database` along with predefined keywords like "ERROR", "CRITICAL", "WARNING" etc in their respective colors. Current search position is highlighed with a background color. Pressing `n` for next and `p` for previous will help navigation.
+
+![image](https://github.com/user-attachments/assets/e3c557cd-651e-433c-8912-ba4f34ea35f8)
+
+### Search once log is displayed
+
+At any point, press `s` to perform a search. You will be prompted to enter a search keyword. It will work the same way as providing the ssearch keyword with `-s` argument.
+
+![image](https://github.com/user-attachments/assets/5dec900d-9f5b-4079-943e-459d61e9179b)

install.sh

@@ -0,0 +1,43 @@
+#!/bin/bash
+
+# Define the alias
+ALIAS="alias stail='python3 $(pwd)/search_tail/__main__.py \"\$@\"'"
+
+# Function to add alias to the given file
+add_alias() {
+  local file=$1
+  if [ -f "$file" ]; then
+    if grep -q "alias stail=" "$file"; then
+      echo "Updating existing alias in $file"
+      sed -i "/alias stail=/c\\$ALIAS" "$file"
+    else
+      echo "Adding alias to $file"
+      echo "$ALIAS" >> "$file"
+    fi
+  else
+    return 1
+  fi
+}
+
+# Add alias to .bashrc and .zshrc if they exist
+added_to_any=false
+if add_alias ~/.bashrc; then
+  source ~/.bashrc
+  echo "Alias added and sourced in ~/.bashrc"
+  added_to_any=true
+fi
+
+if add_alias ~/.zshrc; then
+  source ~/.zshrc
+  echo "Alias added and sourced in ~/.zshrc"
+  added_to_any=true
+fi
+
+# Provide feedback if neither .bashrc nor .zshrc were found
+if [ "$added_to_any" = false ]; then
+  echo "Neither ~/.bashrc nor ~/.zshrc were found. Please manually add the following alias to your terminal configuration file:"
+  echo "$ALIAS"
+else
+  echo "Installation complete. You can now use the 'stail' command."
+fi
+

search_tail/__main__.py

@@ -0,0 +1,55 @@
+"""
+Main module of Search Tail
+This is a tail-like CLI tool with support for search and keyword highlighting
+"""
+
+import argparse
+
+from stail import run
+
+DEFAULT_LINES_TO_DISPLAY = 50
+
+
+def main():
+    """
+    Main function
+    """
+    parser = argparse.ArgumentParser(
+        description="A tail-like CLI tool with support for search and keyword highlighting",
+        formatter_class=argparse.RawTextHelpFormatter,
+    )
+    parser.add_argument(
+        "file",
+        type=str,
+        help="The log file to tail",
+    )
+    parser.add_argument(
+        "-n",
+        type=int,
+        default=DEFAULT_LINES_TO_DISPLAY,
+        help=(
+            "The number of lines to display.\n"
+            "There is no need to explicitly specify '-n' unless to change the default(50 lines).\n"
+            "The following options are available across:\n"
+            "    Use 's' to perform another search.\n"
+            "    Use 'n' to navigate to next match.\n"
+            "    Use 'p' to navigate to previous match.\n"
+            "    Use 'r' to reload the file.\n"
+            "    Use 'q' to quit the program."
+        ),
+    )
+    parser.add_argument("-s", type=str, help="Search and highlight a keyword")
+    args = parser.parse_args()
+
+    if args.n is None:
+        args.n = DEFAULT_LINES_TO_DISPLAY  # Set default value of -n
+    elif args.n is not None and args.n <= 0:
+        args.n = (
+            DEFAULT_LINES_TO_DISPLAY  # Invalid value for -n. Use default value of -n
+        )
+
+    run(args)
+
+
+if __name__ == "__main__":
+    main()

search_tail/config.py

@@ -0,0 +1,27 @@
+class Config:  # pylint: disable=too-few-public-methods
+    """Search Tail - Configuration class"""
+
+    # Predefined keywords and their colors
+    # Feel free to add more as you like.
+    # Please refer to https://en.wikipedia.org/wiki/ANSI_escape_code#Colors for more options.
+    keywords = {
+        "ERROR": "\033[91m",  # Red
+        "CRITICAL": "\033[91m",  # Red
+        "FATAL": "\033[91m",  # Red
+        "EXCEPTION": "\033[91m",  # Red
+        "WARNING": "\033[93m",  # Yellow
+        "WARN": "\033[93m",  # Yellow
+        "NOTICE": "\033[93m",  # Yellow
+        "INFO": "\033[94m",  # Blue
+        "DEBUG": "\033[95m",  # Purple
+        "TRACE": "\033[95m",  # Purple
+        "SUCCESS": "\033[92m",  # Green
+        "INPUT": "\033[96m",  # Cyan
+        "OUTPUT": "\033[96m",  # Cyan
+        "TODO": "\033[96m",  # Cyan
+    }
+
+    RESET_COLOR = "\033[0m"
+    BOLD_FORMAT = "\033[1m"
+    HIGHLIGHT_COLOR = "\033[32m"
+    BACKGROUND_COLOR = "\033[100m"  # Darker grey background for current line

search_tail/stail.py

@@ -0,0 +1,147 @@
+"""
+Implementation of Search-Tail
+"""
+
+import os
+import re
+import sys
+import termios
+import tty
+
+from config import Config
+
+
+def tail(file, lines):
+    """
+    Tails last lines of a file
+    """
+    with open(file, "r", encoding="utf-8") as file_handle:
+        return file_handle.readlines()[-lines:]
+
+
+def print_lines(lines, current_position=None, keyword=None):
+    """
+    Prints lines
+    """
+    os.system("clear")
+    terminal_size = os.get_terminal_size()
+    term_height = terminal_size.lines
+    start = (
+        max(0, current_position - (term_height // 2) + 2)
+        if current_position is not None
+        else 0
+    )
+    end = min(
+        len(lines), start + term_height - 2
+    )  # -2 to account for the status and user input
+    for i in range(start, end):
+        bold = i == current_position
+        highlight_and_print(lines[i], keyword, bold)
+    if current_position is not None:
+        print(f"Keyword '{keyword}' found at line {current_position + 1}")
+
+
+def highlight_and_print(line, keyword=None, bold=False):
+    """Highlight and print a line"""
+    highlighted_line = line
+
+    # Highlight predefined keywords
+    for k, color in Config.keywords.items():
+        highlighted_line = re.sub(
+            f"({k})",
+            f"{color}\\1{Config.RESET_COLOR}",
+            highlighted_line,
+            flags=re.IGNORECASE,
+        )
+
+    # Highlight the specified keyword
+    if keyword:
+        highlighted_line = re.sub(
+            f"({keyword})",
+            f"{Config.HIGHLIGHT_COLOR}\\1{Config.RESET_COLOR}",
+            highlighted_line,
+            flags=re.IGNORECASE,
+        )
+
+    # Apply bold formatting and background color for the entire line if bold is True
+    if bold:
+        background_reset_color = f"{Config.RESET_COLOR}{Config.BACKGROUND_COLOR}"
+        highlighted_line = highlighted_line.replace(
+            Config.RESET_COLOR, background_reset_color
+        )
+        highlighted_line = (
+            f"{Config.BACKGROUND_COLOR}{Config.BOLD_FORMAT}"
+            f"{highlighted_line.strip()}"
+            f"{Config.RESET_COLOR}\n"
+        )
+
+    print(highlighted_line, end="")
+
+
+def search(lines, keyword, direction="next", current_position=None):
+    """Search for a keyword and highlight keyword in a list of lines"""
+    if keyword is None:
+        return None, None
+    if direction == "next":
+        start = current_position + 1 if current_position is not None else 0
+        for i in range(start, len(lines)):
+            if re.search(keyword, lines[i], re.IGNORECASE):
+                return i, lines[i]
+    elif direction == "prev":
+        start = current_position - 1 if current_position is not None else len(lines) - 1
+        for i in range(start, -1, -1):
+            if re.search(keyword, lines[i], re.IGNORECASE):
+                return i, lines[i]
+    return None, None
+
+
+def get_key():
+    """Read a single key from stdin"""
+    fd = sys.stdin.fileno()
+    old_settings = termios.tcgetattr(fd)
+    try:
+        tty.setraw(fd)
+        key = sys.stdin.read(1)
+    finally:
+        termios.tcsetattr(fd, termios.TCSADRAIN, old_settings)
+    return key
+
+
+def run(args):
+    """
+    Main function
+    """
+    lines = tail(args.file, args.n)
+
+    current_position = None
+
+    current_position, _ = search(
+        lines, args.s, direction="next", current_position=current_position
+    )
+    print_lines(lines, current_position, args.s)
+
+    while True:
+        key = get_key()
+        if key == "q":
+            break
+        if key == "r":
+            lines = tail(args.file, args.n)
+            current_position, _ = search(
+                lines, args.s, direction="next", current_position=current_position
+            )
+        if key == "p" and args.s:
+            current_position, _ = search(
+                lines, args.s, direction="prev", current_position=current_position
+            )
+        if key == "n" and args.s:
+            current_position, _ = search(
+                lines, args.s, direction="next", current_position=current_position
+            )
+        if key == "s":
+            new_keyword = input("Enter search keyword: ")
+            args.s = new_keyword
+            current_position, _ = search(
+                lines, args.s, direction="next", current_position=current_position
+            )
+
+        print_lines(lines, current_position, args.s)