Brace Expansion and Globbing Advanced

Brace expansion — text generation

echo {a,b,c}.txt          # a.txt b.txt c.txt
echo {1..5}                # 1 2 3 4 5
echo {01..05}              # 01 02 03 04 05  (zero-padded)
echo {1..10..2}            # 1 3 5 7 9       (step)
echo {a..e}                # a b c d e
mkdir -p project/{src,test,docs}/{2025,2026}

Brace expansion happens before glob expansion and runs even on paths that don't exist — perfect for creating directory trees.

Recursive globbing

ls **/*.py                # zsh; bash needs `shopt -s globstar`
ls src/**/*.{ts,tsx}       # combined with brace

** matches across directory boundaries — way faster than find -name '*.py' for everyday cases.

zsh glob qualifiers

ls *(.)                   # plain files only
ls *(/)                   # directories only
ls *(.om)                 # plain files, ordered by mtime newest first
ls *(.OL[1,5])            # 5 largest plain files
ls *(.m-1)                # plain files modified in the last day

zsh-specific. Compact and astonishingly powerful for one-liners.

extglob (bash)

shopt -s extglob
ls !(*.txt)                # everything except .txt
ls @(foo|bar).log          # exactly foo.log or bar.log
ls *(foo|bar)              # zero or more occurrences

bash equivalent of zsh's pattern alternation. Off by default, hence shopt -s extglob.