feat(#61): support multiple configurations (#67)

Author: hedhyw

README.md

@@ -49,6 +49,7 @@ The application is designed to help in visualization, navigation, and analyzing
 
 ```sh
 jlv file.json
+jlv -config .jlv.jsonc file.json
 ```
 
 | Key    | Action         |
@@ -104,77 +105,11 @@ The application will look for the config `.jlv.jsonc` in the working directory o
 - `$PWD/.jlv.jsonc`;
 - `$HOME/.jlv.jsonc`.
 
+It's also possible to define the path to the configuration using "-config" flag.
+
 The Json path supports the described in [yalp/jsonpath](https://github.com/yalp/jsonpath#jsonpath-quick-intro) syntax.
 
-Example configuration:
-```jsonc
-{
-    // Comments are allowed.
-    "fields": [
-        {
-            "title": "Time", // Max length is 32.
-            // Kind affects rendering. There are:
-            // * time;
-            // * numerictime;
-            // * secondtime;
-            // * millitime;
-            // * microtime;
-            // * level;
-            // * message;
-            // * any.
-            "kind": "numerictime",
-            "ref": [
-                // The application will display the first matched value.
-                "$.timestamp",
-                "$.time",
-                "$.t",
-                "$.ts"
-            ],
-            "width": 30
-        },
-        {
-            "title": "Level",
-            "kind": "level",
-            "ref": [
-                "$.level",
-                "$.lvl",
-                "$.l"
-            ],
-            "width": 10
-        },
-        {
-            "title": "Message",
-            "kind": "message",
-            "ref": [
-                "$.message",
-                "$.msg",
-                "$.error",
-                "$.err"
-            ],
-            "width": 0 // The width will be calculated automatically.
-        },
-        {
-            "title": "Custom",
-            "kind": "any",
-            "ref": [
-                "$.custom"
-            ],
-            "width": 0
-        },
-    ],
-    // Mapping of log level.
-    // Possible values: none, trace, debug, info, warn, error, panic, fatal.
-    "customLevelMapping": {
-        // Replace "10" to "trace" in log level.
-        "10": "trace",
-        "20": "debug",
-        "30": "info",
-        "40": "warn",
-        "50": "error",
-        "60": "fatal"
-    }
-}
-```
+Example configuration: [example.jlv.jsonc](example.jlv.jsonc).
 
 ### Time Formats
 JSON Log Viewer can handle a variety of datetime formats when parsing your logs.

cmd/jlv/main.go

@@ -1,6 +1,7 @@
 package main
 
 import (
+	"flag"
 	"fmt"
 	"os"
 	"path"
@@ -14,16 +15,19 @@ import (
 const configFileName = ".jlv.jsonc"
 
 func main() {
-	if len(os.Args) != 2 {
+	configPath := flag.String("config", "", "Path to the config")
+	flag.Parse()
+
+	if flag.NArg() != 1 {
 		fatalf("Invalid arguments, usage: %s file.log\n", os.Args[0])
 	}
 
-	cfg, err := readConfig()
+	cfg, err := readConfig(*configPath)
 	if err != nil {
 		fatalf("Error reading config: %s\n", err)
 	}
 
-	appModel := app.NewModel(os.Args[1], cfg)
+	appModel := app.NewModel(flag.Args()[0], cfg)
 	program := tea.NewProgram(appModel, tea.WithAltScreen())
 
 	if _, err := program.Run(); err != nil {
@@ -38,9 +42,13 @@ func fatalf(message string, args ...any) {
 
 // readConfig tries to read config from working directory or home directory.
 // If configs are not found, then it returns a default configuration.
-func readConfig() (*config.Config, error) {
+func readConfig(configPath string) (*config.Config, error) {
 	paths := []string{}
 
+	if configPath != "" {
+		paths = append(paths, configPath)
+	}
+
 	workDir, err := os.Getwd()
 	if err == nil {
 		paths = append(paths, path.Join(workDir, configFileName))

example.jlv.jsonc

@@ -0,0 +1,66 @@
+{
+    // Comments are allowed.
+    "fields": [
+        {
+            "title": "Time", // Max length is 32.
+            // Kind affects rendering. There are:
+            // * time;
+            // * numerictime;
+            // * secondtime;
+            // * millitime;
+            // * microtime;
+            // * level;
+            // * message;
+            // * any.
+            "kind": "numerictime",
+            "ref": [
+                // The application will display the first matched value.
+                "$.timestamp",
+                "$.time",
+                "$.t",
+                "$.ts"
+            ],
+            "width": 30
+        },
+        {
+            "title": "Level",
+            "kind": "level",
+            "ref": [
+                "$.level",
+                "$.lvl",
+                "$.l"
+            ],
+            "width": 10
+        },
+        {
+            "title": "Message",
+            "kind": "message",
+            "ref": [
+                "$.message",
+                "$.msg",
+                "$.error",
+                "$.err"
+            ],
+            "width": 0 // The width will be calculated automatically.
+        },
+        {
+            "title": "Custom",
+            "kind": "any",
+            "ref": [
+                "$.custom"
+            ],
+            "width": 0
+        }
+    ],
+    // Mapping of log level.
+    // Possible values: none, trace, debug, info, warn, error, panic, fatal.
+    "customLevelMapping": {
+        // Replace "10" to "trace" in log level.
+        "10": "trace",
+        "20": "debug",
+        "30": "info",
+        "40": "warn",
+        "50": "error",
+        "60": "fatal"
+    }
+}