doctor: add first draft

cmd/tools/vdoctor.v

@@ -0,0 +1,61 @@
+import os
+import term
+import time
+import v.util
+import runtime
+
+fn main(){
+	mut arch_details := []string{}
+	arch_details << '${runtime.nr_cpus()} cpus'
+	if runtime.is_32bit() {
+		arch_details << '32bit'
+	}
+	if runtime.is_64bit() {
+		arch_details << '64bit'
+	}
+	if runtime.is_big_endian() {
+		arch_details << 'big endian'
+	}
+	if runtime.is_little_endian() {
+		arch_details << 'little endian'
+	}
+	line('Processor', arch_details.join(', '))
+	mut os_kind := os.user_os()
+	mut os_details := ''
+	if os_kind == 'linux' {
+		os_details = first_line_of_cmd('lsb_release -d -s')
+	}
+	line('OS', os_kind)
+	line('OS details', os_details)
+	line('CC version', first_line_of_cmd('cc --version'))
+	println(util.bold(term.h_divider('-')))
+	vexe := os.getenv('VEXE')
+	vroot := os.dir(vexe)
+	os.chdir(vroot)
+	line('vroot', vroot)
+	line('vexe', vexe)
+	line('vexe mtime', time.unix(os.file_last_mod_unix(vexe)).str())
+	is_writable_vroot := os.is_writable_folder(vroot) or { false }
+	line('is vroot writable', is_writable_vroot.str())
+	line('V full version', util.full_v_version(true))
+	println(util.bold(term.h_divider('-')))
+	line('Git version', first_line_of_cmd('git --version'))
+	line('Git vroot status', first_line_of_cmd('git describe --dirty --tags'))
+	line('.git/config present', os.is_file('.git/config').str())
+	println(util.bold(term.h_divider('-')))
+}
+
+fn first_line_of_cmd(cmd string) string {
+	x := os.exec(cmd) or {
+		return 'N/A'
+	}
+	if x.exit_code == 0 {
+		return x.output.split_into_lines()[0]
+	}
+	println('first_line_of_cmd error: $x.output')
+	return 'Error'
+}
+
+fn line(label string, value string) {
+	println('$label: ${util.bold(value)}')
+}

cmd/v/v.v

@@ -17,7 +17,7 @@ const (
 		'repl',
 		'build-tools', 'build-examples',
 		'build-vbinaries',
-		'setup-freetype', 'doc'
+		'setup-freetype', 'doc', 'doctor'
 	]
 	list_of_flags_that_allow_duplicates = ['cc', 'd', 'define', 'cf', 'cflags']
 )