Grep vs Glob — The Commonly Confused Code Navigation Tools

⚡ Exam Tested 6 min +25 XP

💡

THE ANALOGY

The difference between a metal detector and a map. A metal detector (grep) scans through soil looking for signals inside it — it searches CONTENT. A map (glob) shows you where paths lead based on their structure — it matches FILE PATHS by pattern.

⚠️ EXAM TRAP — The Wrong Answer People Choose

Using grep when you need glob or vice versa. The exam tests this with specific scenarios — 'find all files named *.test.tsx' needs glob, 'find all files containing the function callRefund' needs grep.

KEY POINTS

1 Grep searches FILE CONTENTS for a pattern — it opens files and looks inside them. Use when you know what the code says but not where it lives.

2 Glob matches FILE PATHS by pattern — it looks at file names and directory structure without opening files. Use when you know where code lives by its naming convention.

3 Grep use cases: find all callers of a function, find all files that import a module, find error messages, find TODO comments.

4 Glob use cases: find all test files (*.test.tsx), find all files in a directory (src/**/*.ts), find all config files.

5 Combining them is powerful: glob to find candidate files, grep to filter by content.

Grep — Search File Contents

# Grep: opens files and searches INSIDE them for a pattern

# Find all files that call the processPayment function
grep_result = grep(
    pattern="processPayment",
    path="src/",
    recursive=True
)
# Returns: list of {file, line_number, line_content} matches

# Find all files that import from the auth module
grep_result = grep(
    pattern=r"from ['\"]\./auth['\"]|from ['\"]../auth['\"]",
    path="src/",
    recursive=True
)

# Find all TODO comments
grep_result = grep(
    pattern="// TODO",
    path="src/",
    recursive=True
)

Use grep when you know WHAT the code says but not WHERE it lives.

Glob — Match File Paths

# Glob: matches file NAMES and PATHS by pattern — doesn't open files

# Find all TypeScript test files
test_files = glob("src/**/*.test.tsx")
test_files = glob("src/**/*.spec.ts")

# Find all configuration files
config_files = glob("**/*.config.{js,ts,json}")

# Find all files in the components directory
component_files = glob("src/components/**/*.tsx")

# Find all files matching a naming convention
api_files = glob("src/api/**/index.ts")

Use glob when you know WHERE code lives by its naming convention.

Combining Grep and Glob

# Find all TypeScript test files that test the auth module
# Step 1: Glob — find all test files by name
all_test_files = glob("src/**/*.test.ts")

# Step 2: Grep — filter to only ones that test auth
auth_test_files = []
for file in all_test_files:
    if grep(pattern="import.*auth", path=file):
        auth_test_files.append(file)

The Exam Scenario Table

Task	Tool
Find all callers of `sendEmail()`	Grep
Find all `*.test.tsx` files	Glob
Find all files that import from `../utils`	Grep
Find all `index.ts` files in `src/`	Glob
Find where `MAX_RETRIES` constant is defined	Grep
Find all JSON config files	Glob
Find all TODO comments	Grep
Find all files in the `components/` directory	Glob

Key Takeaways

Grep = searches inside files — finds patterns in content
Glob = matches file paths — finds files by name/location pattern
Use grep when you know what the code says
Use glob when you know where the code lives by naming convention
Combine them for maximum precision — glob to find candidate files, grep to filter by content