function morgan(format, options) {
var fmt = format
var opts = options || {}
if (format && typeof format === 'object') {
opts = format
fmt = opts.format || 'default'
// smart deprecation message
deprecate('morgan(options): use morgan(' + (typeof fmt === 'string' ? JSON.stringify(fmt) : 'format') + ', options) instead')
}
if (fmt === undefined) {
deprecate('undefined format: specify a format')
}
// output on request instead of response
var immediate = opts.immediate
// check if log entry should be skipped
var skip = opts.skip || false
// format function
var formatLine = typeof fmt !== 'function'
? getFormatFunction(fmt)
: fmt
// stream
var buffer = opts.buffer
var stream = opts.stream || process.stdout
// buffering support
if (buffer) {
deprecate('buffer option')
// flush interval
var interval = typeof buffer !== 'number'
? DEFAULT_BUFFER_DURATION
: buffer
// swap the stream
stream = createBufferStream(stream, interval)
}
return function logger (req, res, next) {
// request data
req._startAt = undefined
req._startTime = undefined
req._remoteAddress = getip(req)
// response data
res._startAt = undefined
res._startTime = undefined
// record request start
recordStartTime.call(req)
function logRequest () {
if (skip !== false && skip(req, res)) {
debug('skip request')
return
}
var line = formatLine(morgan, req, res)
if (line == null) {
debug('skip line')
return
}
debug('log request')
stream.write(line + '\n')
};
if (immediate) {
// immediate log
logRequest()
} else {
// record response start
onHeaders(res, recordStartTime)
// log when response finished
onFinished(res, logRequest)
}
next()
}
}n/a
function compile(format) {
if (typeof format !== 'string') {
throw new TypeError('argument format must be a string')
}
var fmt = format.replace(/"/g, '\\"')
var js = ' "use strict"\n return "' + fmt.replace(/:([-\w]{2,})(?:\[([^\]]+)\])?/g, function (_, name, arg) {
var tokenArguments = 'req, res'
var tokenFunction = 'tokens[' + String(JSON.stringify(name)) + ']'
if (arg !== undefined) {
tokenArguments += ', ' + String(JSON.stringify(arg))
}
return '" +\n (' + tokenFunction + '(' + tokenArguments + ') || "-") + "'
}) + '"'
// eslint-disable-next-line no-new-func
return new Function('tokens, req, res', js)
}...
The URL of the request. This will use `req.originalUrl` if exists, otherwise `req.url`.
##### :user-agent
The contents of the User-Agent header of the request.
### morgan.compile(format)
Compile a format string into a `format` function for use by `morgan`. A format string
is a string that represents a single log line and can utilize token syntax.
Tokens are references by `:token-name`. If tokens accept arguments, they can
be passed using `[]`, for example: `:token-name[pretty]` would pass the string
`'pretty'` as an argument to the token `token-name`.
...function getDateToken(req, res, format) {
var date = new Date()
switch (format || 'web') {
case 'clf':
return clfdate(date)
case 'iso':
return date.toISOString()
case 'web':
return date.toUTCString()
}
}n/a
function developmentFormatLine(tokens, req, res) {
// get the status code if response written
var status = res._header
? res.statusCode
: undefined
// get status color
var color = status >= 500 ? 31 // red
: status >= 400 ? 33 // yellow
: status >= 300 ? 36 // cyan
: status >= 200 ? 32 // green
: 0 // no color
// get colored function
var fn = developmentFormatLine[color]
if (!fn) {
// compile
fn = developmentFormatLine[color] = compile('\x1b[0m:method :url \x1b[' +
color + 'm:status \x1b[0m:response-time ms - :res[content-length]\x1b[0m')
}
return fn(tokens, req, res)
}n/a
function format(name, fmt) {
morgan[name] = fmt
return this
}...
`'pretty'` as an argument to the token `token-name`.
The function returned from `morgan.compile` takes three arguments `tokens`, `req`, and
`res`, where `tokens` is object with all defined tokens, `req` is the HTTP request and
`res` is the HTTP response. The function will return a string that will be the log line,
or `undefined` / `null` to skip logging.
Normally formats are defined using `morgan.format(name, format)`, but for certain
advanced uses, this compile function is directly available.
## Examples
### express/connect
Simple app that will log all request in the Apache combined format to STDOUT
...function getHttpVersionToken(req) {
return req.httpVersionMajor + '.' + req.httpVersionMinor
}n/a
function getMethodToken(req) {
return req.method
}...
#### Using a custom format function
<!-- eslint-disable no-undef -->
``` js
morgan(function (tokens, req, res) {
return [
tokens.method(req, res),
tokens.url(req, res),
tokens.status(req, res),
tokens.res(req, res, 'content-length'), '-',
tokens['response-time'](req, res), 'ms'
].join(' ')
})
```
...function getReferrerToken(req) {
return req.headers['referer'] || req.headers['referrer']
}n/a
function getip(req) {
return req.ip ||
req._remoteAddress ||
(req.connection && req.connection.remoteAddress) ||
undefined
}n/a
function getRemoteUserToken(req) {
// parse basic credentials
var credentials = auth(req)
// return username
return credentials
? credentials.name
: undefined
}n/a
function getRequestToken(req, res, field) {
// get header
var header = req.headers[field.toLowerCase()]
return Array.isArray(header)
? header.join(', ')
: header
}n/a
function getResponseHeader(req, res, field) {
if (!res._header) {
return undefined
}
// get header
var header = res.getHeader(field)
return Array.isArray(header)
? header.join(', ')
: header
}...
``` js
morgan(function (tokens, req, res) {
return [
tokens.method(req, res),
tokens.url(req, res),
tokens.status(req, res),
tokens.res(req, res, 'content-length'), '-',
tokens['response-time'](req, res), 'ms'
].join(' ')
})
```
#### Options
...function getResponseTimeToken(req, res, digits) {
if (!req._startAt || !res._startAt) {
// missing request and/or response start time
return
}
// calculate diff
var ms = (res._startAt[0] - req._startAt[0]) * 1e3 +
(res._startAt[1] - req._startAt[1]) * 1e-6
// return truncated value
return ms.toFixed(digits === undefined ? 3 : digits)
}n/a
function getStatusToken(req, res) {
return res._header
? String(res.statusCode)
: undefined
}...
<!-- eslint-disable no-undef -->
``` js
morgan(function (tokens, req, res) {
return [
tokens.method(req, res),
tokens.url(req, res),
tokens.status(req, res),
tokens.res(req, res, 'content-length'), '-',
tokens['response-time'](req, res), 'ms'
].join(' ')
})
```
#### Options
...function token(name, fn) {
morgan[name] = fn
return this
}...
:method :url :status :res[content-length] - :response-time ms
```
#### Tokens
##### Creating new tokens
To define a token, simply invoke `morgan.token()` with the name and a callback function
.
This callback function is expected to return a string value. The value returned is then
available as ":type" in this case:
<!-- eslint-disable no-undef -->
```js
morgan.token('type', function (req, res) { return req.headers['content-type'] })
...function getUrlToken(req) {
return req.originalUrl || req.url
}...
<!-- eslint-disable no-undef -->
``` js
morgan(function (tokens, req, res) {
return [
tokens.method(req, res),
tokens.url(req, res),
tokens.status(req, res),
tokens.res(req, res, 'content-length'), '-',
tokens['response-time'](req, res), 'ms'
].join(' ')
})
```
...function getUserAgentToken(req) {
return req.headers['user-agent']
}n/a