bin2v: allow direct file output

cmd/tools/vbin2v.v

@@ -2,9 +2,10 @@ module main
 
 import os
 import flag
+import strings
 
 const (
-	tool_version = '0.0.3'
+	tool_version = '0.0.4'
 	tool_description = 'Converts a list of arbitrary files into a single v module file.'
 )
 
@@ -14,12 +15,15 @@ mut:
 	prefix      string
 	show_help   bool
 	module_name string
+	write_file  bool
 }
 
-fn (context Context) header() {
-	println('module ${context.module_name}')
-	println('')
+fn (context Context) header() string {
+	mut header_s := ''
+	header_s += 'module ${context.module_name}\n'
+	header_s += '\n'
 	allfiles := context.files.join(' ')
+
 	mut options := []string{}
 	if context.prefix.len > 0 {
 		options << '-p ${context.prefix}'
@@ -27,39 +31,48 @@ fn (context Context) header() {
 	if context.module_name.len > 0 {
 		options << '-m ${context.module_name}'
 	}
+	if context.write_file {
+		options << '-w'
+	}
 	soptions := options.join(' ')
-	println('// File generated by:')
-	println('//    v bin2v ${allfiles} ${soptions}')
-	println('// Please, do not edit this file.')
-	println('// Your changes may be overwritten.')
-	println('')
-	println('const (')
+
+	header_s += '// File generated by:\n'
+	header_s += '//    v bin2v ${allfiles} ${soptions}\n'
+	header_s += '// Please, do not edit this file.\n'
+	header_s += '// Your changes may be overwritten.\n'
+	header_s += '\n'
+	header_s += 'const (\n'
+
+	return header_s
 }
 
-fn (context Context) footer() {
-	println(')')
+fn (context Context) footer() string {
+	return ')\n'
 }
 
-fn (context Context) file2v(file string) {
+fn (context Context) file2v(file string) string {
+	mut sb := strings.new_builder(1000)
 	fname := os.file_name(file)
 	fname_no_dots := fname.replace('.', '_')
 	byte_name := '${context.prefix}${fname_no_dots}'
 	fbytes := os.read_bytes(file) or {
 		eprintln('Error: $err')
-		return
+		return ''
 	}
 	fbyte := fbytes[0]
-	println('  ${byte_name}_len = ${fbytes.len}')
-	print('  ${byte_name} = [ byte(${fbyte}), \n  ')
+	sb.write('  ${byte_name}_len = ${fbytes.len}\n')
+	sb.write('  ${byte_name} = [ byte(${fbyte}), \n  ')
 	for i := 1; i < fbytes.len; i++ {
 		b := int(fbytes[i]).str()
-		print('${b:4s}, ')
+		sb.write('${b:4s}, ')
 		if 0 == i % 16 {
-			print('\n  ')
+			sb.write('\n  ')
 		}
 	}
-	println('\n]!!')
-	println('')
+	sb.write('\n]!!\n')
+	sb.write('\n')
+
+	return sb.str()
 }
 
 fn main() {
@@ -70,8 +83,9 @@ fn main() {
 	fp.description(tool_description)
 	fp.arguments_description('FILE [FILE]...')
 	context.show_help = fp.bool('help', `h`, false, 'Show this help screen.')
-	context.module_name = fp.string('module', `m`, 'binary', 'Name of the generated module.\n')
-	context.prefix = fp.string('prefix', `p`, '', 'A prefix put before each resource name.\n')
+	context.module_name = fp.string('module', `m`, 'binary', 'Name of the generated module.')
+	context.prefix = fp.string('prefix', `p`, '', 'A prefix put before each resource name.')
+	context.write_file = fp.bool('write', `w`, false, 'Write directly to a file. The module name is used as filename.')
 	if context.show_help {
 		println(fp.usage())
 		exit(0)
@@ -86,9 +100,20 @@ fn main() {
 		exit(0)
 	}
 	context.files = real_files
-	context.header()
-	for file in real_files {
-		context.file2v(file)
+
+	if context.write_file {
+		mut out_file := os.create('${context.module_name}.v') or { panic(err) }
+		out_file.write(context.header())
+		for file in real_files {
+			out_file.write(context.file2v(file))
+		}
+		out_file.write(context.footer())
+	}
+	else {
+		println(context.header())
+		for file in real_files {
+			println(context.file2v(file))
+		}
+		println(context.footer())
 	}
-	context.footer()
 }

cmd/v/help/bin2v.txt

@@ -1,9 +1,9 @@
-Usage: 
+Usage:
 v bin2v [options] FILE [FILE]...
 
 Converts a list of arbitrary files into a single v module file.
 
-You can use this tool to embed binary files, like pictures or fonts inside 
+You can use this tool to embed binary files, like pictures or fonts inside
 the executable of a v program, such that it would not need access to external
 resources during runtime, and it would be as self-contained as possible.
 
@@ -11,3 +11,4 @@ Options:
   -h, --help                Show this help screen.
   -m, --module <string>     Name of the generated module.
   -p, --prefix <string>     A prefix put before each resource name.
+  -w, --write               Write directly to a file. The module name is used as filename.