which-first

Show which copy of a command your shell will actually run, and every other copy that exists but never will.

npm: C:\tools\npm.cmd
  shadowed: C:\Program Files\nodejs\npm.cmd
  shadowed: C:\Program Files\nodejs\npm.ps1

The problem it exists for

where npm lists every copy. It does not tell you which one wins, and on Windows the answer is not obvious: npm.cmd beats npm.exe because of PATHEXT, and the first directory on PATH beats all the later ones. People install a tool, run it, and get the old copy that happens to sit earlier on PATH. which-first prints the winner first and labels the rest shadowed.

Install

npm install which-first

Node 18 or newer. No dependencies.

Use

which-first npm
which-first node git python

Exit code 0 when every command resolves, 1 when one does not, 2 when you give it nothing to look up.

Resolution follows the shell: directories in PATH order, PATHEXT extensions in order, case-insensitive on Windows, repeated directories skipped. A directory that does not exist is ignored rather than reported as an error.