do for core

Signature

> do {flags} (closure) ...rest

Flags

• --ignore-errors, -i: ignore errors as the closure runs
• --capture-errors, -c: catch errors as the closure runs, and return them
• --env: keep the environment defined inside the command

Parameters

• closure: The closure to run.
• ...rest: The parameter(s) for the closure.

Input/output types:

Examples

Run the closure

> do { echo hello }
hello

Run a stored first-class closure

> let text = "I am enclosed"; let hello = {|| echo $text}; do $hello
I am enclosed

Run the closure and ignore both shell and external program errors

> do --ignore-errors { thisisnotarealcommand }

Abort the pipeline if a program returns a non-zero exit code

> do --capture-errors { nu --commands 'exit 1' } | myscarycommand

Run the closure with a positional, type-checked parameter

> do {|x:int| 100 + $x } 77
177

Run the closure with pipeline input

> 77 | do { 100 + $in }
177

Run the closure with a default parameter value

> 77 | do {|x=100| $x + $in }
177

Run the closure with two positional parameters

> do {|x,y| $x + $y } 77 100
177

Run the closure and keep changes to the environment

> do --env { $env.foo = 'bar' }; $env.foo
bar