add 'errorfmt' option to format error messages

Related #154

complete.go

@@ -118,6 +118,7 @@ var (
 		"period",
 		"scrolloff",
 		"tabstop",
+		"errorfmt",
 		"filesep",
 		"ifs",
 		"previewer",

doc.go

@@ -117,6 +117,7 @@ The following options can be used to customize the behavior of lf:
     period          integer  (default 0) (zero to disable periodic loading)
     scrolloff       integer  (default 0)
     tabstop         integer  (default 8)
+    errorfmt        string   (default "\033[7;31;47m%s\033[0m")
     filesep         string   (default "\n")
     ifs             string   (default '') (not exported if empty)
     previewer       string   (default '') (not filtered if empty)

docstring.go

@@ -120,6 +120,7 @@ The following options can be used to customize the behavior of lf:
     period          integer  (default 0) (zero to disable periodic loading)
     scrolloff       integer  (default 0)
     tabstop         integer  (default 8)
+    errorfmt        string   (default "\033[7;31;47m%s\033[0m")
     filesep         string   (default "\n")
     ifs             string   (default ”) (not exported if empty)
     previewer       string   (default ”) (not filtered if empty)

eval.go

@@ -205,6 +205,8 @@ func (e *setExpr) eval(app *app, args []string) {
 			return
 		}
 		gOpts.tabstop = n
+	case "errorfmt":
+		gOpts.errorfmt = e.val
 	case "filesep":
 		gOpts.filesep = e.val
 	case "ifs":

lf.1

@@ -132,6 +132,7 @@ The following options can be used to customize the behavior of lf:
     period          integer  (default 0) (zero to disable periodic loading)
     scrolloff       integer  (default 0)
     tabstop         integer  (default 8)
+    errorfmt        string   (default "\e033[7;31;47m%s\e033[0m")
     filesep         string   (default "\en")
     ifs             string   (default ”) (not exported if empty)
     previewer       string   (default ”) (not filtered if empty)

opts.go

@@ -43,6 +43,7 @@ var gOpts struct {
 	period         int
 	scrolloff      int
 	tabstop        int
+	errorfmt       string
 	filesep        string
 	ifs            string
 	previewer      string
@@ -75,6 +76,7 @@ func init() {
 	gOpts.period = 0
 	gOpts.scrolloff = 0
 	gOpts.tabstop = 8
+	gOpts.errorfmt = "\033[7;31;47m%s\033[0m"
 	gOpts.filesep = "\n"
 	gOpts.promptfmt = "\033[32;1m%u@%h\033[0m:\033[34;1m%w/\033[0m\033[1m%f\033[0m"
 	gOpts.shell = gDefaultShell

ui.go

@@ -499,7 +499,7 @@ func (ui *ui) echomsgf(format string, a ...interface{}) {
 }
 
 func (ui *ui) echoerr(msg string) {
-	ui.msg = fmt.Sprintf("\033[7;31;47m%s\033[0m", msg)
+	ui.msg = fmt.Sprintf(gOpts.errorfmt, msg)
 	log.Printf("error: %s", msg)
 }