Struct Hook 

pub struct Hook { /* private fields */ }

Available on crate feature shell-init only.

A command of the CLI that the shell runs once, in the foreground, before its first prompt.

It runs as <bin> <subcommand>, and only when the environment variable variable is set to a non-empty value and bin is on PATH. Each shell removes the hook before running the command, so a later prompt never runs it again.

In bash, another tool, such as bash-preexec, can rewrite PROMPT_COMMAND so that the removal misses. So bash’s hook also sets a variable it checks first.

Every part is one word the shell reads without quoting, which Hook::new checks once.

Implementations

impl Hook

pub fn new( bin: &str, subcommand: &str, variable: &str, ) -> Result<Self, HookError>

Declare the hook that runs bin subcommand when variable is set.

Errors

Returns a HookError naming the first part that is not a plain word.

• bin and subcommand take letters, digits, -, and _, and start with a letter or digit.
• variable takes letters, digits, and _, and does not start with a digit.

pub fn script(&self, shell: Shell) -> Script

The script that installs this hook in shell.

bash runs it from PROMPT_COMMAND, as a string or, from bash 5.1, an array. zsh runs it from precmd_functions, and fish on the fish_prompt event. The bash hook returns the exit status it found, so a prompt command after it still reads the status of the user’s last command.

Trait Implementations

impl Clone for Hook

fn clone(&self) -> Self

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Hook

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Eq for Hook

impl PartialEq for Hook

fn eq(&self, other: &Self) -> bool

Equality operator ==.

fn ne(&self, other: &Rhs) -> bool

Inequality operator !=.

impl StructuralPartialEq for Hook