SNOW-1634712 Support for toml file connection configuration

cmd/tomlfileconnection/.gitignore

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+tomlfileconnection.go

cmd/tomlfileconnection/Makefile

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+include ../../gosnowflake.mak
+CMD_TARGET=tomlfileconnection
+
+## Install
+install: cinstall
+
+## Run
+run: crun
+
+## Lint
+lint: clint
+
+## Format source codes
+fmt: cfmt
+
+.PHONY: install run lint fmt

cmd/tomlfileconnection/tomlfileconnection.go

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+// Example: How to connect to the server with the toml file configuration
+// Prerequiste: following the Snowflake doc: https://docs.snowflake.com/en/developer-guide/snowflake-cli-v2/connecting/specify-credentials
+package main
+
+import (
+	"database/sql"
+	"flag"
+	"fmt"
+	"log"
+	"os"
+
+	sf "github.com/snowflakedb/gosnowflake"
+)
+
+func main() {
+	if !flag.Parsed() {
+		flag.Parse()
+	}
+
+	os.Setenv("SNOWFLAKE_HOME", "<The directory path where the toml file exists>")
+	os.Setenv("SNOWFLAKE_DEFAULT_CONNECTION_NAME", "<DSN Name>")
+
+	cfg, err := sf.LoadConnectionConfig()
+	if err != nil {
+		log.Fatalf("failed to create Config, err: %v", err)
+	}
+	dsn, err := sf.DSN(cfg)
+	if err != nil {
+		log.Fatalf("failed to create DSN from Config: %v, err: %v", cfg, err)
+	}
+
+	db, err := sql.Open("snowflake", dsn)
+	if err != nil {
+		log.Fatalf("failed to connect. %v, err: %v", dsn, err)
+	}
+	defer db.Close()
+	query := "SELECT 1"
+	rows, err := db.Query(query) // no cancel is allowed
+	if err != nil {
+		log.Fatalf("failed to run a query. %v, err: %v", query, err)
+	}
+	defer rows.Close()
+	var v int
+	for rows.Next() {
+		err := rows.Scan(&v)
+		if err != nil {
+			log.Fatalf("failed to get result. err: %v", err)
+		}
+		if v != 1 {
+			log.Fatalf("failed to get 1. got: %v", v)
+		}
+	}
+	if rows.Err() != nil {
+		fmt.Printf("ERROR: %v\n", rows.Err())
+		return
+	}
+	fmt.Printf("Congrats! You have successfully run %v with Snowflake DB!\n", query)
+}