Go to main content

man pages section 1: User Commands

Exit Print View

Updated: Wednesday, February 9, 2022
 
 

npx (1)

Name

npx - Run a command from a local or remote npm package Synopsis npm exec -- <pkg>[@<version>] [args...] npm exec --package=<pkg>[@<version>] -- <cmd> [args...] npm exec -c '<cmd> [args...]' npm exec --package=foo -c '<cmd> [args...]' npx <pkg>[@<specifier>] [args...] npx -p <pkg>[@<specifier>] <cmd> [args...] npx -c '<cmd> [args...]' npx -p <pkg>[@<specifier>] -c '<cmd> [args...]' alias: npm x, npx --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) Description This command allows you to run an arbitrary command from an npm package (either one installed locally, or fetched remotely), in a similar con- text as running it via npm run. Whatever packages are specified by the --package option will be pro- vided in the PATH of the executed command, along with any locally installed package executables. The --package option may be specified multiple times, to execute the supplied command in an environment where all specified packages are available. If any requested packages are not present in the local project depen- dencies, then they are installed to a folder in the npm cache, which is added to the PATH environment variable in the executed process. A prompt is printed (which can be suppressed by providing either --yes or --no). Package names provided without a specifier will be matched with what- ever version exists in the local project. Package names with a speci- fier will only be considered a match if they have the exact same name and version as the local dependency. If no -c or --call option is provided, then the positional arguments are used to generate the command string. If no --package options are provided, then npm will attempt to determine the executable name from the package specifier provided as the first positional argument accord- ing to the following heuristic: o If the package has a single entry in its bin field in package.json, or if all entries are aliases of the same command, then that command will be used. o If the package has multiple bin entries, and one of them matches the unscoped portion of the name field, then that command will be used. o If this does not result in exactly one option (either because there are no bin entries, or none of them match the name of the package), then npm exec exits with an error. To run a binary other than the named binary, specify one or more --package options, which will prevent npm from inferring the package from the first command argument. npx vs npm exec When run via the npx binary, all flags and options must be set prior to any positional arguments. When run via npm exec, a double-hyphen -- flag can be used to suppress npm's parsing of switches and options that should be sent to the executed command. For example: $ npx foo@latest bar --package=@npmcli/foo In this case, npm will resolve the foo package name, and run the fol- lowing command: $ foo bar --package=@npmcli/foo Since the --package option comes after the positional arguments, it is treated as an argument to the executed command. In contrast, due to npm's argument parsing logic, running this command is different: $ npm exec foo@latest bar --package=@npmcli/foo In this case, npm will parse the --package option first, resolving the @npmcli/foo package. Then, it will execute the following command in that context: $ foo@latest bar 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 npx command above: $ npm exec -- foo@latest bar --package=@npmcli/foo Examples Run the version of tap in the local dependencies, with the provided arguments: $ npm exec -- tap --bail test/foo.js $ npx tap --bail test/foo.js Run a command other than the command whose name matches the package name by specifying a --package option: $ npm exec --package=foo -- bar --bar-argument # ~ or ~ $ npx --package=foo bar --bar-argument Run an arbitrary shell script, in the context of the current project: $ npm x -c 'eslint && say "hooray, lint passed"' $ npx -c 'eslint && say "hooray, lint passed"' Compatibility with Older npx Versions The npx binary was rewritten in npm v7.0.0, and the standalone npx package deprecated at that time. npx uses the npm exec command instead of a separate argument parser and install process, with some affor- dances to maintain backwards compatibility with the arguments it accepted in previous versions. This resulted in some shifts in its functionality: o Any npm config value may be provided. o To prevent security and user-experience problems from mistyping pack- age names, npx prompts before installing anything. Suppress this prompt with the -y or --yes option. o The --no-install option is deprecated, and will be converted to --no. o Shell fallback functionality is removed, as it is not advisable. o The -p argument is a shorthand for --parseable in npm, but shorthand for --package in npx. This is maintained, but only for the npx exe- cutable. o The --ignore-existing option is removed. Locally installed bins are always present in the executed process PATH. o The --npm option is removed. npx will always use the npm it ships with. o The --node-arg and -n options are removed. o The --always-spawn option is redundant, and thus removed. o The --shell option is replaced with --script-shell, but maintained in the npx executable for backwards compatibility. See Also o npm help run-script o npm help scripts o npm help test o npm help start o npm help restart o npm help stop o npm help config

Synopsis

Please see following description for synopsis

Description

NPX(1)                                                                  NPX(1)



NAME
       npx - Run a command from a local or remote npm package

   Synopsis
         npm exec -- <pkg>[@<version>] [args...]
         npm exec --package=<pkg>[@<version>] -- <cmd> [args...]
         npm exec -c '<cmd> [args...]'
         npm exec --package=foo -c '<cmd> [args...]'

         npx <pkg>[@<specifier>] [args...]
         npx -p <pkg>[@<specifier>] <cmd> [args...]
         npx -c '<cmd> [args...]'
         npx -p <pkg>[@<specifier>] -c '<cmd> [args...]'

         alias: npm x, npx

         --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)

   Description
       This command allows you to run an arbitrary command from an npm package
       (either one installed locally, or fetched remotely), in a similar  con-
       text as running it via npm run.

       Whatever  packages  are  specified by the --package option will be pro-
       vided in the PATH of the  executed  command,  along  with  any  locally
       installed  package  executables.  The --package option may be specified
       multiple times, to execute the supplied command in an environment where
       all specified packages are available.

       If  any  requested packages are not present in the local project depen-
       dencies, then they are installed to a folder in the npm cache, which is
       added  to  the  PATH  environment  variable in the executed process.  A
       prompt is printed (which can be suppressed by providing either --yes or
       --no).

       Package  names  provided without a specifier will be matched with what-
       ever version exists in the local project.  Package names with a  speci-
       fier  will  only be considered a match if they have the exact same name
       and version as the local dependency.

       If no -c or --call option is provided, then  the  positional  arguments
       are  used  to generate the command string.  If no --package options are
       provided, then npm will attempt to determine the executable  name  from
       the package specifier provided as the first positional argument accord-
       ing to the following heuristic:

       o If the package has a single entry in its bin field  in  package.json,
         or  if all entries are aliases of the same command, then that command
         will be used.

       o If the package has multiple bin entries, and one of them matches  the
         unscoped portion of the name field, then that command will be used.

       o If  this  does not result in exactly one option (either because there
         are no bin entries, or none of them match the name of  the  package),
         then npm exec exits with an error.


       To  run  a  binary  other  than  the  named binary, specify one or more
       --package options, which will prevent npm from  inferring  the  package
       from the first command argument.

   npx vs npm exec
       When run via the npx binary, all flags and options must be set prior to
       any positional arguments.  When run via npm exec,  a  double-hyphen  --
       flag can be used to suppress npm's parsing of switches and options that
       should be sent to the executed command.

       For example:

         $ npx foo@latest bar --package=@npmcli/foo

       In this case, npm will resolve the foo package name, and run  the  fol-
       lowing command:

         $ foo bar --package=@npmcli/foo

       Since  the --package option comes after the positional arguments, it is
       treated as an argument to the executed command.

       In contrast, due to npm's argument parsing logic, running this  command
       is different:

         $ npm exec foo@latest bar --package=@npmcli/foo

       In  this case, npm will parse the --package option first, resolving the
       @npmcli/foo package.  Then, it will execute the  following  command  in
       that context:

         $ foo@latest bar

       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 npx command above:

         $ npm exec -- foo@latest bar --package=@npmcli/foo

   Examples
       Run  the  version  of  tap in the local dependencies, with the provided
       arguments:

         $ npm exec -- tap --bail test/foo.js
         $ npx tap --bail test/foo.js

       Run a command other than the command whose  name  matches  the  package
       name by specifying a --package option:

         $ npm exec --package=foo -- bar --bar-argument
         # ~ or ~
         $ npx --package=foo bar --bar-argument

       Run an arbitrary shell script, in the context of the current project:

         $ npm x -c 'eslint && say "hooray, lint passed"'
         $ npx -c 'eslint && say "hooray, lint passed"'

   Compatibility with Older npx Versions
       The  npx  binary  was  rewritten  in npm v7.0.0, and the standalone npx
       package deprecated at that time.  npx uses the npm exec command instead
       of  a  separate  argument  parser and install process, with some affor-
       dances to  maintain  backwards  compatibility  with  the  arguments  it
       accepted in previous versions.

       This resulted in some shifts in its functionality:

       o Any npm config value may be provided.

       o To prevent security and user-experience problems from mistyping pack-
         age names, npx prompts before  installing  anything.   Suppress  this
         prompt with the -y or --yes option.

       o The --no-install option is deprecated, and will be converted to --no.

       o Shell fallback functionality is removed, as it is not advisable.

       o The  -p argument is a shorthand for --parseable in npm, but shorthand
         for --package in npx.  This is maintained, but only for the npx  exe-
         cutable.

       o The  --ignore-existing option is removed.  Locally installed bins are
         always present in the executed process PATH.

       o The --npm option is removed.  npx will always use the  npm  it  ships
         with.

       o The --node-arg and -n options are removed.

       o The --always-spawn option is redundant, and thus removed.

       o The --shell option is replaced with --script-shell, but maintained in
         the npx executable for backwards compatibility.


   See Also
       o npm help run-script

       o npm help scripts

       o npm help test

       o npm help start

       o npm help restart

       o npm help stop

       o npm help config




ATTRIBUTES
       See attributes(7) for descriptions of the following attributes:


       +---------------+--------------------------+
       |ATTRIBUTE TYPE |     ATTRIBUTE VALUE      |
       +---------------+--------------------------+
       |Availability   | runtime/nodejs/nodejs-16 |
       +---------------+--------------------------+
       |Stability      | Pass-thru volatile       |
       +---------------+--------------------------+

NOTES
       Source code for open source software components in Oracle  Solaris  can
       be found at https://www.oracle.com/downloads/opensource/solaris-source-
       code-downloads.html.

       This    software    was    built    from    source     available     at
       https://github.com/oracle/solaris-userland.    The  original  community
       source   was   downloaded   from     https://github.com/nodejs/node/ar-
       chive/v16.11.1.zip.

       Further information about this software can be found on the open source
       community website at https://github.com/nodejs/node.



                                 October 2021                           NPX(1)