bash-equivalents.md

Bash to Nushell Translation

File and Directory Operations

Bash	Nushell
ls	ls
ls -la	ls --long --all or ls -la
ls -d */	ls | where type == dir
find . -name "*.rs"	glob **/*.rs or ls **/*.rs
mkdir -p path	mkdir path (creates parents automatically)
touch file	touch file
cp src dst	cp src dst
cp -r src dst	cp -r src dst
mv old new	mv old new
rm file	rm file
rm -rf dir	rm -r dir
cat file	open --raw file
head -5 file	open --raw file | lines | first 5
tail -5 file	open --raw file | lines | last 5
wc -l file	open --raw file | lines | length

Output Redirection

Bash	Nushell
> file	o> file or | save file
>> file	o>> file or | save --append file
> /dev/null	| ignore
> /dev/null 2>&1	o+e>| ignore
2>&1	o+e>| ...
cmd | tee log | cmd2	cmd | tee { save log } | cmd2

Text Processing

Bash	Nushell
grep pattern	where $it =~ pattern or find pattern
grep -r pattern .	open --raw file | lines | where $it =~ pattern
sed 's/old/new/'	str replace 'old' 'new'
sed 's/old/new/g'	str replace --all 'old' 'new'
awk '{print $1}'	split column ' ' | get column0
sort	sort
sort -u	sort | uniq
uniq	uniq
cut -d: -f1	split column ':' | get column0
tr '[:upper:]' '[:lower:]'	str downcase

Variables and Environment

Bash	Nushell
VAR=value	let var = "value"
export VAR=value	$env.VAR = "value"
echo $VAR	$env.VAR
echo $HOME	$env.HOME
echo $PATH	$env.PATH (list on macOS/Linux)
echo $?	$env.LAST_EXIT_CODE
unset VAR	hide-env VAR
${VAR:-default}	$env.VAR? | default "value"
export PATH=$PATH:/new	$env.PATH = ($env.PATH | append "/new")
FOO=bar cmd	FOO=bar cmd (same syntax)

Command Execution

Bash	Nushell
cmd1 && cmd2	cmd1; cmd2
cmd1 || cmd2	try { cmd1 } catch { cmd2 }
$(command)	(command)
`command`	(command)
command &	job spawn { command }
jobs	job list
kill %1	job kill $id
type cmd	which cmd
man cmd	help cmd
bash -c 'code'	nu -c 'code'
source script.sh	source script.nu

Control Flow

Bash	Nushell
if [ cond ]; then ... fi	if $cond { ... }
[ -f file ]	"file" | path exists
[ -d dir ]	("dir" | path exists) and ("dir" | path type) == "dir"
for f in *.md; do echo $f; done	ls *.md | each { $in.name }
for i in $(seq 1 10); do ...; done	for i in 1..10 { ... }
while read line; do ...; done < file	open file | lines | each {|line| ... }
case $x in ... esac	match $x { pattern => result, ... }

Pipes and Subshells

Bash	Nushell
cmd | head -5	cmd | first 5
cmd | tail -5	cmd | last 5
\ (line continuation)	( wrap in parens )
read var	let var = (input)
read -s secret	let secret = (input -s)

History

Bash	Nushell
!!	!! (inserts, doesn't execute)
!$	!$
Ctrl+R	Ctrl+R

Key Behavioral Differences

1. Structured vs text: Nushell pipelines pass tables/records, not text streams
2. Immutable by default: let is immutable; use mut when needed
3. No word splitting: Nushell doesn't split variables on whitespace
4. No glob expansion in variables: Globs only expand in command position
5. Static parsing: Code is parsed before execution; no eval equivalent
6. Implicit return: Last expression is the return value; no echo needed
7. > is comparison: Use o> or save for file redirection