fmsg: implement suspend in writer

This removes the requirement to call fmsg.Exit on every exit path, and enables direct use of the "log" package. However, fmsg.BeforeExit is still encouraged when possible to catch exit on suspended output.

Signed-off-by: Ophestra <cat@gensokyo.uk>

cmd/fpkg/main.go

@@ -2,8 +2,10 @@ package main
 
 import (
 	"flag"
+	"log"
 	"os"
 
+	"git.gensokyo.uk/security/fortify/internal"
 	"git.gensokyo.uk/security/fortify/internal/fmsg"
 )
 
@@ -11,7 +13,7 @@ const shell = "/run/current-system/sw/bin/bash"
 
 func init() {
 	if err := os.Setenv("SHELL", shell); err != nil {
-		fmsg.Fatalf("cannot set $SHELL: %v", err)
+		log.Fatalf("cannot set $SHELL: %v", err)
 	}
 }
 
@@ -24,14 +26,14 @@ func init() {
 }
 
 func main() {
-	fmsg.SetPrefix("fpkg")
+	fmsg.Prepare("fpkg")
 
 	flag.Parse()
-	fmsg.SetVerbose(flagVerbose)
+	fmsg.Store(flagVerbose)
 
 	args := flag.Args()
 	if len(args) < 1 {
-		fmsg.Fatal("invalid argument")
+		log.Fatal("invalid argument")
 	}
 
 	switch args[0] {
@@ -41,8 +43,8 @@ func main() {
 		actionStart(args[1:])
 
 	default:
-		fmsg.Fatal("invalid argument")
+		log.Fatal("invalid argument")
 	}
 
-	fmsg.Exit(0)
+	internal.Exit(0)
 }