npm-exec.1

.TH "NPM\-EXEC" "1" "June 2021" "" ""
.SH "NAME"
\fBnpm-exec\fR \- Run a command from a local or remote npm package
.SS Synopsis
.P
.RS 2
.nf
npm exec \-\- <pkg>[@<version>] [args\.\.\.]
npm exec \-\-package=<pkg>[@<version>] \-\- <cmd> [args\.\.\.]
npm exec \-c '<cmd> [args\.\.\.]'
npm exec \-\-package=foo \-c '<cmd> [args\.\.\.]'
npm exec [\-\-ws] [\-w <workspace\-name] [args\.\.\.]

npx <pkg>[@<specifier>] [args\.\.\.]
npx \-p <pkg>[@<specifier>] <cmd> [args\.\.\.]
npx \-c '<cmd> [args\.\.\.]'
npx \-p <pkg>[@<specifier>] \-c '<cmd> [args\.\.\.]'
Run without \-\-call or positional args to open interactive subshell

alias: npm x, npx

common options:
\-\-package=<pkg> (may be specified multiple times)
\-p is a shorthand for \-\-package only when using npx executable
\-c <cmd> \-\-call=<cmd> (may not be mixed with positional arguments)
.fi
.RE
.SS Description
.P
This command allows you to run an arbitrary command from an npm package
(either one installed locally, or fetched remotely), in a similar context
as running it via \fBnpm run\fP\|\.
.P
Run without positional arguments or \fB\-\-call\fP, this allows you to
interactively run commands in the same sort of shell environment that
\fBpackage\.json\fP scripts are run\.  Interactive mode is not supported in CI
environments when standard input is a TTY, to prevent hangs\.
.P
Whatever packages are specified by the \fB\-\-package\fP option will be
provided in the \fBPATH\fP of the executed command, along with any locally
installed package executables\.  The \fB\-\-package\fP option may be
specified multiple times, to execute the supplied command in an environment
where all specified packages are available\.
.P
If any requested packages are not present in the local project
dependencies, then they are installed to a folder in the npm cache, which
is added to the \fBPATH\fP environment variable in the executed process\.  A
prompt is printed (which can be suppressed by providing either \fB\-\-yes\fP or
\fB\-\-no\fP)\.
.P
Package names provided without a specifier will be matched with whatever
version exists in the local project\.  Package names with a specifier will
only be considered a match if they have the exact same name and version as
the local dependency\.
.P
If no \fB\-c\fP or \fB\-\-call\fP option is provided, then the positional arguments
are used to generate the command string\.  If no \fB\-\-package\fP options
are provided, then npm will attempt to determine the executable name from
the package specifier provided as the first positional argument according
to the following heuristic:
.RS 0
.IP \(bu 2
If the package has a single entry in its \fBbin\fP field in \fBpackage\.json\fP,
or if all entries are aliases of the same command, then that command
will be used\.
.IP \(bu 2
If the package has multiple \fBbin\fP entries, and one of them matches the
unscoped portion of the \fBname\fP field, then that command will be used\.
.IP \(bu 2
If this does not result in exactly one option (either because there are
no bin entries, or none of them match the \fBname\fP of the package), then
\fBnpm exec\fP exits with an error\.

.RE
.P
To run a binary \fIother than\fR the named binary, specify one or more
\fB\-\-package\fP options, which will prevent npm from inferring the package from
the first command argument\.
.SS \fBnpx\fP vs \fBnpm exec\fP
.P
When run via the \fBnpx\fP binary, all flags and options \fImust\fR be set prior to
any positional arguments\.  When run via \fBnpm exec\fP, a double\-hyphen \fB\-\-\fP
flag can be used to suppress npm's parsing of switches and options that
should be sent to the executed command\.
.P
For example:
.P
.RS 2
.nf
$ npx foo@latest bar \-\-package=@npmcli/foo
.fi
.RE
.P
In this case, npm will resolve the \fBfoo\fP package name, and run the
following command:
.P
.RS 2
.nf
$ foo bar \-\-package=@npmcli/foo
.fi
.RE
.P
Since the \fB\-\-package\fP option comes \fIafter\fR the positional arguments, it is
treated as an argument to the executed command\.
.P
In contrast, due to npm's argument parsing logic, running this command is
different:
.P
.RS 2
.nf
$ npm exec foo@latest bar \-\-package=@npmcli/foo
.fi
.RE
.P
In this case, npm will parse the \fB\-\-package\fP option first, resolving the
\fB@npmcli/foo\fP package\.  Then, it will execute the following command in that
context:
.P
.RS 2
.nf
$ foo@latest bar
.fi
.RE
.P
The double\-hyphen character is recommended to explicitly tell npm to stop
parsing command line options and switches\.  The following command would
thus be equivalent to the \fBnpx\fP command above:
.P
.RS 2
.nf
$ npm exec \-\- foo@latest bar \-\-package=@npmcli/foo
.fi
.RE
.SS Configuration
<!\-\- AUTOGENERATED CONFIG DESCRIPTIONS START \-\->
<!\-\- automatically generated, do not edit manually \-\->
.SS \fBpackage\fP
.RS 0
.IP \(bu 2
Default:
.IP \(bu 2
Type: String (can be set multiple times)

.RE
.P
The package to install for npm help \fBexec\fP
.SS \fBcall\fP
.RS 0
.IP \(bu 2
Default: ""
.IP \(bu 2
Type: String

.RE
.P
Optional companion option for \fBnpm exec\fP, \fBnpx\fP that allows for specifying a
custom command to be run along with the installed packages\.
.P
.RS 2
.nf
npm exec \-\-package yo \-\-package generator\-node \-\-call "yo node"
.fi
.RE
.SS \fBworkspace\fP
.RS 0
.IP \(bu 2
Default:
.IP \(bu 2
Type: String (can be set multiple times)

.RE
.P
Enable running a command in the context of the configured workspaces of the
current project while filtering by running only the workspaces defined by
this configuration option\.
.P
Valid values for the \fBworkspace\fP config are either:
.RS 0
.IP \(bu 2
Workspace names
.IP \(bu 2
Path to a workspace directory
.IP \(bu 2
Path to a parent workspace directory (will result to selecting all of the
nested workspaces)

.RE
.P
When set for the \fBnpm init\fP command, this may be set to the folder of a
workspace which does not yet exist, to create the folder and set it up as a
brand new workspace within the project\.
.P
This value is not exported to the environment for child processes\.
.SS \fBworkspaces\fP
.RS 0
.IP \(bu 2
Default: false
.IP \(bu 2
Type: Boolean

.RE
.P
Enable running a command in the context of \fBall\fR the configured
workspaces\.
.P
This value is not exported to the environment for child processes\.
<!\-\- AUTOGENERATED CONFIG DESCRIPTIONS END \-\->

.SS Examples
.P
Run the version of \fBtap\fP in the local dependencies, with the provided
arguments:
.P
.RS 2
.nf
$ npm exec \-\- tap \-\-bail test/foo\.js
$ npx tap \-\-bail test/foo\.js
.fi
.RE
.P
Run a command \fIother than\fR the command whose name matches the package name
by specifying a \fB\-\-package\fP option:
.P
.RS 2
.nf
$ npm exec \-\-package=foo \-\- bar \-\-bar\-argument
# ~ or ~
$ npx \-\-package=foo bar \-\-bar\-argument
.fi
.RE
.P
Run an arbitrary shell script, in the context of the current project:
.P
.RS 2
.nf
$ npm x \-c 'eslint && say "hooray, lint passed"'
$ npx \-c 'eslint && say "hooray, lint passed"'
.fi
.RE
.SS Workspaces support
.P
You may use the \fBworkspace\fP or \fBworkspaces\fP configs in order to run an
arbitrary command from an npm package (either one installed locally, or fetched
remotely) in the context of the specified workspaces\.
If no positional argument or \fB\-\-call\fP option is provided, it will open an
interactive subshell in the context of each of these configured workspaces one
at a time\.
.P
Given a project with configured workspaces, e\.g:
.P
.RS 2
.nf
\|\.
+\-\- package\.json
`\-\- packages
   +\-\- a
   |   `\-\- package\.json
   +\-\- b
   |   `\-\- package\.json
   `\-\- c
       `\-\- package\.json
.fi
.RE
.P
Assuming the workspace configuration is properly set up at the root level
\fBpackage\.json\fP file\. e\.g:
.P
.RS 2
.nf
{
    "workspaces": [ "\./packages/*" ]
}
.fi
.RE
.P
You can execute an arbitrary command from a package in the context of each of
the configured workspaces when using the \fBworkspaces\fP configuration options,
in this example we're using \fBeslint\fR to lint any js file found within each
workspace folder:
.P
.RS 2
.nf
npm exec \-\-ws \-\- eslint \./*\.js
.fi
.RE
.SS Filtering workspaces
.P
It's also possible to execute a command in a single workspace using the
\fBworkspace\fP config along with a name or directory path:
.P
.RS 2
.nf
npm exec \-\-workspace=a \-\- eslint \./*\.js
.fi
.RE
.P
The \fBworkspace\fP config can also be specified multiple times in order to run a
specific script in the context of multiple workspaces\. When defining values for
the \fBworkspace\fP config in the command line, it also possible to use \fB\-w\fP as a
shorthand, e\.g:
.P
.RS 2
.nf
npm exec \-w a \-w b \-\- eslint \./*\.js
.fi
.RE
.P
This last command will run the \fBeslint\fP command in both \fB\|\./packages/a\fP and
\fB\|\./packages/b\fP folders\.
.SS Compatibility with Older npx Versions
.P
The \fBnpx\fP binary was rewritten in npm v7\.0\.0, and the standalone \fBnpx\fP
package deprecated at that time\.  \fBnpx\fP uses the \fBnpm exec\fP
command instead of a separate argument parser and install process, with
some affordances to maintain backwards compatibility with the arguments it
accepted in previous versions\.
.P
This resulted in some shifts in its functionality:
.RS 0
.IP \(bu 2
Any \fBnpm\fP config value may be provided\.
.IP \(bu 2
To prevent security and user\-experience problems from mistyping package
names, \fBnpx\fP prompts before installing anything\.  Suppress this
prompt with the \fB\-y\fP or \fB\-\-yes\fP option\.
.IP \(bu 2
The \fB\-\-no\-install\fP option is deprecated, and will be converted to \fB\-\-no\fP\|\.
.IP \(bu 2
Shell fallback functionality is removed, as it is not advisable\.
.IP \(bu 2
The \fB\-p\fP argument is a shorthand for \fB\-\-parseable\fP in npm, but shorthand
for \fB\-\-package\fP in npx\.  This is maintained, but only for the \fBnpx\fP
executable\.
.IP \(bu 2
The \fB\-\-ignore\-existing\fP option is removed\.  Locally installed bins are
always present in the executed process \fBPATH\fP\|\.
.IP \(bu 2
The \fB\-\-npm\fP option is removed\.  \fBnpx\fP will always use the \fBnpm\fP it ships
with\.
.IP \(bu 2
The \fB\-\-node\-arg\fP and \fB\-n\fP options are removed\.
.IP \(bu 2
The \fB\-\-always\-spawn\fP option is redundant, and thus removed\.
.IP \(bu 2
The \fB\-\-shell\fP option is replaced with \fB\-\-script\-shell\fP, but maintained
in the \fBnpx\fP executable for backwards compatibility\.

.RE
.SS A note on caching
.P
The npm cli utilizes its internal package cache when using the package
name specified\.  You can use the following to change how and when the
cli uses this cache\. See npm help \fBcache\fP for more on
how the cache works\.
.SS prefer\-online
.P
Forces staleness checks for packages, making the cli look for updates
immediately even if the package is already in the cache\.
.SS prefer\-offline
.P
Bypasses staleness checks for packages\.  Missing data will still be
requested from the server\. To force full offline mode, use \fBoffline\fP\|\.
.SS offline
.P
Forces full offline mode\. Any packages not locally cached will result in
an error\.
.SS workspace
.RS 0
.IP \(bu 2
Default:
.IP \(bu 2
Type: String (can be set multiple times)

.RE
.P
Enable running a command in the context of the configured workspaces of the
current project while filtering by running only the workspaces defined by
this configuration option\.
.P
Valid values for the \fBworkspace\fP config are either:
.RS 0
.IP \(bu 2
Workspace names
.IP \(bu 2
Path to a workspace directory
.IP \(bu 2
Path to a parent workspace directory (will result to selecting all of the
nested workspaces)

.RE
.P
This value is not exported to the environment for child processes\.
.SS workspaces
.RS 0
.IP \(bu 2
Alias: \fB\-\-ws\fP
.IP \(bu 2
Type: Boolean
.IP \(bu 2
Default: \fBfalse\fP

.RE
.P
Run scripts in the context of all configured workspaces for the current
project\.
.SS See Also
.RS 0
.IP \(bu 2
npm help run\-script
.IP \(bu 2
npm help scripts
.IP \(bu 2
npm help test
.IP \(bu 2
npm help start
.IP \(bu 2
npm help restart
.IP \(bu 2
npm help stop
.IP \(bu 2
npm help config
.IP \(bu 2
npm help workspaces

.RE