We take logger as a function to receive a record and output to a stream, and elecPen is a simple logger creator.
elecPen(writable, prefix, dateFormat)
| Param | Description |
|---|---|
| writables | One or an array of writable stream for logging |
| prefix | The prefix of the record |
| dateFormat | Date format for logger or pass true to use the default format |
A set of logger is provided by a default logger creator which provide some useful logger like info or error.
| Option | Type | Description |
|---|---|---|
| infoFile | string, function | File name for logging info and verbose |
| errFile | string, function | File name for logging error and warning |
| timestamp | string, boolean | Date format for logger or pass true to use the default format |
| append | boolean | If file exists, append new entries to it instead of truncating |
| logToConsole | boolean | Output the message to console, it will be default to true in dev mode |
- logger.verbose
- logger.info
- logger.warning
- logger.error
You can you a set of default logger:
// use default logger
const opts = {
infoFile: 'info.log', // record info and verbose
errFile: 'err.log', // record error and warning
timestamp: true,
append: true // default to true
}
const http = requrie('http')
const logger = require('elecpen').defaultLogger(opts)
http.createServer((req, res) => {
logger.info('Recieve a request. Path: %s', req.path)
res.end('Hello world.')
})
.listen(4000, _ => {
logger.info('Server listening...')
})Dynamic file name is supported, and it is useful to record log by separated file.
const opts = {
infoFile () {
const now = new Date()
return `log-${now.getFullYear()}-${now.getMonth() + 1}`
},
errFile: 'err.log'
}
const logger = require('elecpen').defaultLogger(opts)
logger.info('Hello World!')Or create you own logger:
const fs = require('fs')
const elecpen = require('elecpen')
const recorder = elecpen.streamRecorder()
const log = function (msg) {
// dynamic stream
const stream = recorder(
_ => `log-${Date.now()}.log`,
name => fs.createWriteStream(name, { flags: 'a' })
)
stream && elecpen(stream, 'Message', timestamp)(msg)
}
log('Hello World!')MIT
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