You can search for a text string across multiple files from the command line using grep on Unix-like systems or findstr on Windows. 1. Use grep -r "search_string" /path/to/directory for recursive searches, optionally adding -n, -i, or -l for line numbers, case insensitivity, or filenames only. 2. Filter file types with --include="*.txt" or combine find with grep -l for more control. 3. On Windows, use findstr /s "search_string" *.txt, noting its limitations in flexibility and regex support. 4. Speed up searches with grep -F for fixed strings or tools like ripgrep (rg) for faster performance on large codebases.

You can search for a text string across multiple files directly from the command line using tools like grep (on Unix-like systems) or findstr (on Windows). Here's how to do it effectively.

Use grep with the -r option for recursive searching

If you're on Linux, macOS, or using WSL on Windows, grep is your go-to tool. The -r (or --recursive) flag tells grep to search through all files in a directory and its subdirectories.

For example:

grep -r "search_string" /path/to/directory

This will print out each matching line along with the filename.

Tips:

• Add -n to show line numbers.
• Use -i to ignore case sensitivity.
• Add -l if you only want the list of filenames that contain the string.

Include file patterns with --include or combine with find

Sometimes you don’t want to search all files—just certain types. You can filter which files to search using --include.

Example:

grep -r --include="*.txt" "search_string" /path/to/directory

This only searches .txt files.

Alternatively, pair grep with find for more control:

find /path/to/directory -name "*.log" -exec grep -l "search_string" {} \;

This finds all .log files and executes grep on them, showing only filenames with matches.

On Windows, use findstr with /s and file extensions

Windows users can use findstr, which works similarly but has slightly different syntax.

To search recursively:

findstr /s "search_string" *.txt

This looks for the string in all .txt files in the current directory and subdirectories.

Limitations:

• It’s less flexible than grep.
• Case-sensitive by default. Use /i to ignore case.
• Regular expression support exists via /r, but it's not as powerful.

Bonus: Speed up large searches with grep -F or parallel tools

If you're searching for a literal string (not a regex), use:

grep -r -F "exact_string" .

The -F flag treats the pattern as a fixed string, not a regular expression, which speeds things up.

For very large codebases or many files, consider tools like ripgrep (rg), which is faster and respects .gitignore rules by default.

Just install it and try:

rg "search_string" /path/to/code

That's basically how it works — quick and powerful once you know the right flags.

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