Add option for logging only the message

Author: bcelenza

README.md

@@ -69,6 +69,12 @@ Pipe the CSV output into a markdown formatter for sharing with friends (using [`
 $ cwq --log-group MyLogGroup 'filter @type = "REPORT" | status max(@maxMemoryUsed / 1000 / 1000) as maxMemoryUsedMB by bin(5m)' | csvtomd
 ```
 
+Log only the message from the returne data (using `-m` or `--message-only`):
+
+```bash
+$ cwq --message-only --logGroup MyLogGroup 'filter @message like /ERROR'
+```
+
 ### Log Group Matching
 
 You can provide a glob expression to the `--log-group` argument to match log group names by prefix:

package-lock.json

@@ -1,6 +1,6 @@
 {
   "name": "cwq",
-  "version": "1.0.7",
+  "version": "1.0.8",
   "description": "A CLI for CloudWatch Logs Insights",
   "author": "Brian Celenza",
   "license": "Apache-2.0",

package.json

@@ -41,6 +41,12 @@ const args = yargs
     default: 'now',
     description: 'When to end the search (duration or ISO 8601 format)',
   })
+  .option('message-only', {
+    alias: 'm',
+    type: 'boolean',
+    default: false,
+    description: 'Return just the message in plain-text format (no CSV)',
+  })
   .help()
   .alias('help', 'h').argv;
 
@@ -150,14 +156,19 @@ process.on('SIGINT', async () => {
   }
 
   // Output the results in the desired format
-  switch (args.format) {
-    case 'csv':
-      console.log(new CsvParser().parse(results));
-      break;
-    case 'json':
-      console.log(JSON.stringify(results));
-      break;
+  if (args['message-only']) {
+    results.forEach((r) => console.log(r['@message']));
+  } else {
+    switch (args.format) {
+      case 'csv':
+        console.log(new CsvParser().parse(results));
+        break;
+      case 'json':
+        console.log(JSON.stringify(results));
+        break;
+    }
   }
+  
 })().catch((e: Error) => {
   console.error(`Error: ${e.message}`);
   process.exit(1);