grep.py•4.78 kB
"""
Search Strategy for standard grep
"""
import shutil
import subprocess
from typing import Dict, List, Optional, Tuple
from .base import SearchStrategy, parse_search_output, create_word_boundary_pattern, is_safe_regex_pattern
class GrepStrategy(SearchStrategy):
"""
Search strategy using the standard 'grep' command-line tool.
This is intended as a fallback for when more advanced tools like
ugrep, ripgrep, or ag are not available.
"""
@property
def name(self) -> str:
"""The name of the search tool."""
return 'grep'
def is_available(self) -> bool:
"""Check if 'grep' command is available on the system."""
return shutil.which('grep') is not None
def search(
self,
pattern: str,
base_path: str,
case_sensitive: bool = True,
context_lines: int = 0,
file_pattern: Optional[str] = None,
fuzzy: bool = False,
regex: bool = False
) -> Dict[str, List[Tuple[int, str]]]:
"""
Execute a search using standard grep.
Args:
pattern: The search pattern
base_path: Directory to search in
case_sensitive: Whether search is case sensitive
context_lines: Number of context lines to show
file_pattern: File pattern to filter
fuzzy: Enable word boundary matching
regex: Enable regex pattern matching
"""
# -r: recursive, -n: line number
cmd = ['grep', '-r', '-n']
# Prepare search pattern
search_pattern = pattern
if regex:
# Use regex mode - check for safety first
if not is_safe_regex_pattern(pattern):
raise ValueError(f"Potentially unsafe regex pattern: {pattern}")
cmd.append('-E') # Extended Regular Expressions
elif fuzzy:
# Use word boundary pattern for partial matching
search_pattern = create_word_boundary_pattern(pattern)
cmd.append('-E') # Extended Regular Expressions
else:
# Auto-detect if pattern looks like a safe regex
if is_safe_regex_pattern(pattern):
# Pattern contains regex chars, use extended regex mode
cmd.append('-E')
else:
# Use literal string search
cmd.append('-F')
if not case_sensitive:
cmd.append('-i')
if context_lines > 0:
cmd.extend(['-A', str(context_lines)])
cmd.extend(['-B', str(context_lines)])
if file_pattern:
# Note: grep's --include uses glob patterns, not regex
cmd.append(f'--include={file_pattern}')
exclude_dirs = getattr(self, 'exclude_dirs', [])
exclude_file_patterns = getattr(self, 'exclude_file_patterns', [])
processed_dirs = set()
for directory in exclude_dirs:
normalized = directory.strip()
if not normalized or normalized in processed_dirs:
continue
cmd.append(f'--exclude-dir={normalized}')
processed_dirs.add(normalized)
processed_files = set()
for pattern in exclude_file_patterns:
normalized = pattern.strip()
if not normalized or normalized in processed_files:
continue
if normalized.startswith('!'):
normalized = normalized[1:]
cmd.append(f'--exclude={normalized}')
processed_files.add(normalized)
# Add -- to treat pattern as a literal argument, preventing injection
cmd.append('--')
cmd.append(search_pattern)
cmd.append('.') # Use current directory since we set cwd=base_path
try:
# grep exits with 1 if no matches are found, which is not an error.
# It exits with 0 on success (match found). >1 for errors.
process = subprocess.run(
cmd,
capture_output=True,
text=True,
encoding='utf-8',
errors='replace',
check=False,
cwd=base_path # Set working directory to project base path for proper pattern resolution
)
if process.returncode > 1:
raise RuntimeError(f"grep failed with exit code {process.returncode}: {process.stderr}")
return parse_search_output(process.stdout, base_path)
except FileNotFoundError:
raise RuntimeError("'grep' not found. Please install it and ensure it's in your PATH.")
except Exception as e:
raise RuntimeError(f"An error occurred while running grep: {e}")