oldv: use green color for tracing/diagnostic lines

cmd/tools/modules/scripting/scripting.v

@@ -1,6 +1,11 @@
 module scripting
 
 import os
+import term
+
+const (
+	term_colors = term.can_show_color_on_stdout()
+)
 
 pub fn set_verbose(on bool) {
 	// setting a global here would be the obvious solution,
@@ -13,24 +18,30 @@ pub fn set_verbose(on bool) {
 	}
 }
 
+pub fn cprintln(message string) {
+	mut omessage := message
+	omessage = if term_colors { term.green(omessage) } else { omessage }
+	println(omessage)
+}
+
 pub fn verbose_trace(label string, message string) {
 	if os.getenv('VERBOSE').len > 0 {
 		slabel := 'scripting.${label}'
-		println('# ${slabel:-25s} : $message')
+		cprintln('# ${slabel:-25s} : $message')
 	}
 }
 
 pub fn verbose_trace_exec_result(x os.Result) {
 	if os.getenv('VERBOSE').len > 0 {
-		println('#   cmd.exit_code : ${x.exit_code.str():-4s}  cmd.output:')
-		println('# ----------------------------------- #')
+		cprintln('#   cmd.exit_code : ${x.exit_code.str():-4s}  cmd.output:')
+		cprintln('# ----------------------------------- #')
 		mut lnum := 1
 		lines := x.output.split_into_lines()
 		for line in lines {
-			println('# ${lnum:3d}: $line')
+			cprintln('# ${lnum:3d}: $line')
 			lnum++
 		}
-		println('# ----------------------------------- #')
+		cprintln('# ----------------------------------- #')
 	}
 }
 

cmd/tools/oldv.v

@@ -79,7 +79,7 @@ fn main() {
 	} else {
 		context.commit_v = scripting.run('git rev-list -n1 HEAD')
 	}
-	println('#################  context.commit_v: $context.commit_v #####################')
+	scripting.cprintln('#################  context.commit_v: $context.commit_v #####################')
 	context.path_v = vgit.normalized_workpath_for_commit(context.vgo.workdir, context.commit_v)
 	context.path_vc = vgit.normalized_workpath_for_commit(context.vgo.workdir, 'vc')
 	if !os.is_dir(context.vgo.workdir) {
@@ -98,13 +98,13 @@ fn main() {
 	context.compile_oldv_if_needed()
 
 	scripting.chdir(context.path_v)
-	println('#     v commit hash: $context.commit_v_hash')
-	println('#   checkout folder: $context.path_v')
+	scripting.cprintln('#     v commit hash: $context.commit_v_hash')
+	scripting.cprintln('#   checkout folder: $context.path_v')
 	if context.cmd_to_run.len > 0 {
 		cmdres := os.exec(context.cmd_to_run) or {
 			panic(err)
 		}
-		println('#           command: ${context.cmd_to_run:-34s} exit code: ${cmdres.exit_code:-4d}  result:')
+		scripting.cprintln('#           command: ${context.cmd_to_run:-34s} exit code: ${cmdres.exit_code:-4d}  result:')
 		println(cmdres.output)
 		exit(cmdres.exit_code)
 	}