Modern CLI Tools

Modern CLI Tools

Use fd, rg, fzf, and bat instead of their legacy counterparts. Each is faster, has sensible defaults (respects .gitignore, colorizes output, handles Unicode), and has a more consistent interface.

fd — Find Files

Install: brew install fd / apt install fd-find (binary may be fdfind)

Basic Usage

fd PATTERN               # find files matching pattern (name search)
fd PATTERN PATH          # search within a specific directory
fd -e py                 # find by extension
fd -t f                  # files only (-t d = dirs, -t l = symlinks)
fd -H                    # include hidden files
fd -I                    # include files ignored by .gitignore
fd -0                    # null-delimited output (for xargs -0)

Common Replacements

# find . -name "*.md" -type f
fd -e md

# find . -name "*.log" -type f -mtime +7
fd -e log --changed-before 7d

# find . -name "*.py" -exec grep -l "import os" {} \;
fd -e py -x grep -l "import os"

# find . -type d -name __pycache__
fd -t d __pycache__

# find . -maxdepth 2 -name "*.json"
fd -e json --max-depth 2

Execute Commands on Results

fd -e py -x wc -l        # run wc -l on each .py file
fd -e log -X rm          # delete all .log files (X = batch, x = one-by-one)
fd -e html -x sed -i 's/foo/bar/g'

rg — Ripgrep (Search File Contents)

Install: brew install ripgrep / apt install ripgrep

Basic Usage

rg PATTERN               # search in current directory recursively
rg PATTERN PATH          # search in specific path
rg -i PATTERN            # case-insensitive
rg -l PATTERN            # list matching files only
rg -c PATTERN            # count matches per file
rg -n PATTERN            # show line numbers (on by default)
rg -v PATTERN            # invert match
rg -w PATTERN            # whole-word match
rg -F PATTERN            # fixed string (no regex)
rg -U PATTERN            # multiline mode

Filtering by File Type

rg PATTERN -t py         # Python files only
rg PATTERN -t js -t ts   # JS and TS files
rg PATTERN -T json       # exclude JSON files
rg --type-list           # list all known types

Common Replacements

# grep -r "TODO" . --include="*.py"
rg "TODO" -t py

# grep -rn "def main" src/
rg "def main" src/

# grep -rli "import React"
rg -l "import React"

# grep -r "password" . --exclude-dir=.git
rg "password"            # .gitignore respected automatically

# grep -rn "^class " --include="*.rb"
rg "^class " -t ruby

Useful Flags

rg PATTERN -A 3          # 3 lines after match
rg PATTERN -B 3          # 3 lines before match
rg PATTERN -C 3          # 3 lines context (before + after)
rg PATTERN --hidden      # search hidden files
rg PATTERN -g "*.md"     # glob filter
rg PATTERN -g "!vendor/" # exclude glob
rg PATTERN --no-ignore   # ignore .gitignore
rg PATTERN -j 4          # use 4 threads
rg PATTERN -o            # print only the matching part
rg PATTERN --stats       # show search statistics

fzf — Fuzzy Finder

Install: brew install fzf / apt install fzf

fzf reads from stdin and lets the user interactively fuzzy-filter the input. It prints the selected item(s) to stdout, making it composable with any other command.

Basic Interactive Use

fzf                      # fuzzy-search stdin, print selection
fzf -m                   # multi-select (Tab to mark, Enter to confirm)
fzf -q "initial query"   # start with pre-filled search
fzf --height 40%         # render inline (not full-screen)
fzf --reverse            # input at top
fzf --border             # draw border

Find and Open Files

# interactively select a file and open it
$EDITOR $(fzf)

# use fd as the source (respects .gitignore, faster)
FZF_DEFAULT_COMMAND='fd -t f' fzf

# preview file contents while browsing
fzf --preview 'bat --color=always {}'

Search and Jump

# interactively search git log and show diff
git log --oneline | fzf --preview 'git show {1}'

# pick a branch to checkout
git branch | fzf | xargs git checkout

# kill a process interactively
ps aux | fzf -m | awk '{print $2}' | xargs kill

# cd into a directory chosen interactively
cd $(fd -t d | fzf)

Pipe Integration

# grep through rg results interactively
rg --line-number "TODO" | fzf

# select from history
history | fzf | sh

# select multiple files for git add
git status -s | fzf -m | awk '{print $2}' | xargs git add

Shell Integration

After $(brew prefix)/opt/fzf/install or fzf --bash:

• Ctrl-R — fuzzy search shell history
• Ctrl-T — fuzzy-insert file path at cursor
• Alt-C — fuzzy cd into subdirectory

bat — Better cat

Install: brew install bat / apt install bat (binary may be batcat)

Basic Usage

bat FILE                 # view file with syntax highlighting + line numbers
bat FILE1 FILE2          # concatenate multiple files
bat -n FILE              # line numbers only (no other decorations)
bat -A FILE              # show non-printable characters
bat --plain FILE         # no decoration (plain output like cat)
bat --paging=never FILE  # no pager, stream directly
bat -l json FILE         # force a language for highlighting
bat --list-languages     # show all supported languages

Common Replacements

# cat file.py
bat file.py

# cat -n file.py
bat -n file.py

# cat *.md | less
bat *.md

# cat package.json | jq
bat --plain package.json | jq   # or just: cat package.json | jq

Use as a Pager or Previewer

# use bat as git's pager for diffs
git diff | bat -l diff

# use bat in fzf preview (colorized)
fzf --preview 'bat --color=always --style=numbers {}'

# set as default MANPAGER
export MANPAGER="sh -c 'col -bx | bat -l man -p'"

Useful Flags

bat --style=plain        # no line numbers, no git markers, no border
bat --style=numbers,grid # pick specific style components
bat --color=always       # force color even when piped (e.g., into fzf)
bat --wrap=never         # disable line wrapping
bat -r 10:20 FILE        # show only lines 10–20
bat --diff FILE          # show only changed lines (requires git)

Combined Patterns

Find → Search → Preview → Edit

# Find Python files with TODO, preview with bat, open selected in editor
rg -l "TODO" -t py | fzf --preview 'bat --color=always {}' | xargs $EDITOR

Find Files and View

# Fuzzy-pick a file and view it with bat
bat $(fd -t f | fzf)

Search Log Files

# Tail + fzf filter (static snapshot)
rg "ERROR" app.log | fzf

Batch Rename

# Find and preview files before acting
fd -e txt -x bat --style=header {}

Availability Check

Before using these tools in scripts, verify they are available:

command -v fd  || echo "fd not found: brew install fd"
command -v rg  || echo "rg not found: brew install ripgrep"
command -v fzf || echo "fzf not found: brew install fzf"
command -v bat || command -v batcat || echo "bat not found: brew install bat"

On Debian/Ubuntu fd may be fdfind and bat may be batcat. Check with which fd fdfind bat batcat.

When to Stick with Legacy Tools

• grep: When the environment is guaranteed to lack rg (e.g., minimal Docker images, POSIX-only scripts).
• find: In portable shell scripts (/bin/sh) where fd cannot be assumed.
• cat: When piping raw bytes, using -A for non-printable inspection already provided by bat -A, or in pipelines where adding a pager would break things.
• less/more: For arbitrary paging; bat uses them internally anyway.