Evaluating Code
The-e or --evaluate flag can be used to check code.
node --eval "2 * 4"
# this will show no output
node -e "console.log(14+7)"
# 21
Print Rather Than Evaluate
node --print "4 * 5"
# 20
node -p "console.log(3 * 7)"
# 21
# undefined-pprints undefined after the console.log because the console.log does not return anything other than undefined
Importing node modules
- node "modules" come with the library/binary (fs, http, etc)
- these modules can be required directly from cmd input
- this can be useful because the core node modules are cross-platform!!
using the print flag with modules
node -p "Object.keys(require('fs'))"
# will return...
[
'appendFile', 'appendFileSync', 'access',
'accessSync', 'chown', 'chownSync',
'chmod', 'chmodSync', 'close',
'closeSync', 'copyFile', 'copyFileSync',
'createReadStream', 'createWriteStream', 'exists',
'existsSync', 'fchown', 'fchownSync',
'fchmod', 'fchmodSync', 'fdatasync',
'fdatasyncSync', 'fstat', 'fstatSync',
'fsync', 'fsyncSync', 'ftruncate',
'ftruncateSync', 'futimes', 'futimesSync',
'lchown', 'lchownSync', 'lchmod',
'lchmodSync', 'link', 'linkSync',
'lstat', 'lstatSync', 'lutimes',
'lutimesSync', 'mkdir', 'mkdirSync',
'mkdtemp', 'mkdtempSync', 'open',
'openSync', 'opendir', 'opendirSync',
'readdir', 'readdirSync', 'read',
'readSync', 'readv', 'readvSync',
'readFile', 'readFileSync', 'readlink',
'readlinkSync', 'realpath', 'realpathSync',
'rename', 'renameSync', 'rm',
'rmSync', 'rmdir', 'rmdirSync',
'stat', 'statSync', 'symlink',
'symlinkSync', 'truncate', 'truncateSync',
'unwatchFile', 'unlink', 'unlinkSync',
'utimes', 'utimesSync', 'watch',
'watchFile', 'writeFile', 'writeFileSync',
'write', 'writeSync', 'writev',
'writevSync', 'Dir', 'Dirent',
'Stats', 'ReadStream', 'WriteStream',
'FileReadStream', 'FileWriteStream', '_toUnixTimestamp',
'F_OK', 'R_OK', 'W_OK',
'X_OK', 'constants', 'promises'
]