From 3e932d5e5f59b1b0348ae7749020ec78d9182ca4 Mon Sep 17 00:00:00 2001
From: Lilleman auf Larv <lilleman@larvit.se>
Date: Wed, 7 Oct 2026 21:47:27 +0200
Subject: [PATCH] Answer architecture round 5, stability round 4 and
 product-owner round 4: an argument that is a lone reference is echoed back,
 and a hint for a template holding a backslash pipes it through printf

---
 cmd/fejkdata/main.go      | 17 ++++++++++++++---
 cmd/fejkdata/main_test.go |  3 ++-
 2 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/cmd/fejkdata/main.go b/cmd/fejkdata/main.go
index 620b640..af9bfb8 100644
--- a/cmd/fejkdata/main.go
+++ b/cmd/fejkdata/main.go
@@ -292,10 +292,12 @@ func operandError(arg string) error {
 		return fmt.Errorf("%s; read a file from stdin: fejkdata < %s", unexpected, shellQuoted(arg))
 	}
 	example := pipeHint
-	if inline, err := fejkdata.IsTemplate(arg); inline {
-		example = "echo " + shellQuoted(arg) + " | fejkdata"
+	if _, lone := loneReference(arg); lone {
+		example = piped(arg)
+	} else if inline, err := fejkdata.IsTemplate(arg); inline {
+		example = piped(arg)
 	} else if _, lone := loneReference("{/" + arg + "}"); lone && err == nil {
-		example = "echo " + shellQuoted("{/"+arg+"}") + " | fejkdata"
+		example = piped("{/" + arg + "}")
 	}
 	return fmt.Errorf("%s; the template is read from stdin: %s", unexpected, example)
 }
@@ -492,6 +494,15 @@ func spacedReference(template string, err error) error {
 	return err
 }
 
+// piped is the command piping template to fejkdata; some shells' echo reads a backslash
+// as an escape, so a template holding one goes through printf.
+func piped(template string) string {
+	if strings.ContainsRune(template, '\\') {
+		return "printf '%s' " + shellQuoted(template) + " | fejkdata"
+	}
+	return "echo " + shellQuoted(template) + " | fejkdata"
+}
+
 // shellQuoted is s as a shell reads it back: bare where it holds nothing a shell expands.
 func shellQuoted(s string) string {
 	if s != "" && !strings.ContainsAny(s, " \t\r\n'\"$`\\*?[]{}()<>|&;#~!") {
diff --git a/cmd/fejkdata/main_test.go b/cmd/fejkdata/main_test.go
index 0aaef6c..a08e81b 100644
--- a/cmd/fejkdata/main_test.go
+++ b/cmd/fejkdata/main_test.go
@@ -249,10 +249,11 @@ func TestRunTakesNoOperand(t *testing.T) {
 		want string
 	}{
 		{[]string{"sv_SE.person"}, "echo '{/sv_SE.person}' | fejkdata"},
-		{[]string{"{/sv_SE.person}"}, "echo '{/sv_SE.person}' | fejkdata"},
+		{[]string{"{/en_US.person}"}, "echo '{/en_US.person}' | fejkdata"},
 		{[]string{"name: {/sv_SE.person.last}"}, "echo 'name: {/sv_SE.person.last}' | fejkdata"},
 		{[]string{"geo.US.locality[O'Fallon].name"}, `echo '{/geo.US.locality[O'\''Fallon].name}' | fejkdata`},
 		{[]string{"en_US.address"}, "echo '{/en_US.address}' | fejkdata"},
+		{[]string{`C:\temp {/sv_SE.person}`}, `printf '%s' 'C:\temp {/sv_SE.person}' | fejkdata`},
 		{[]string{"-"}, "drop it"},
 		{[]string{file}, "fejkdata < " + file},
 	} {