refs #67: add -o option to show.

Signed-off-by: Eric Wang <skygragon@gmail.com>

Author: skygragon

lib/commands/show.js

@@ -43,6 +43,12 @@ const cmd = {
         describe: 'Programming language of the source code',
         choices:  config.sys.langs
       })
+      .option('o', {
+        alias:    'outdir',
+        type:     'string',
+        describe: 'Where to save source code',
+        default:  '.'
+      })
       .option('q', core.filters.query)
       .option('t', core.filters.tag)
       .option('x', {
@@ -66,12 +72,22 @@ const cmd = {
   }
 };
 
-function genFileName(problem, lang) {
+function genFileName(problem, opts) {
+  const path = require('path');
+  const params = [
+    problem.id,
+    problem.slug,
+    '',
+    h.langToExt(opts.lang)
+  ];
+
   // try to use a new filename to avoid overwrite by mistake
-  let name = problem.id + '.' + problem.slug + h.langToExt(lang);
   let i = 0;
-  while (fs.existsSync(name))
-    name = problem.id + '.' + problem.slug + '.' + (i++) + h.langToExt(lang);
+  let name;
+  do {
+    name = path.join(opts.outdir, params.join('.').replace(/\.+/g, '.'));
+    params[2] = i++;
+  } while (fs.existsSync(name));
   return name;
 }
 
@@ -106,7 +122,8 @@ function showProblem(problem, argv) {
 
   let filename;
   if (argv.gen) {
-    filename = genFileName(problem, argv.lang);
+    filename = genFileName(problem, argv);
+    h.mkdir(argv.outdir);
     fs.writeFileSync(filename, code);
 
     if (argv.editor !== undefined) {

lib/commands/submission.js

@@ -30,7 +30,7 @@ const cmd = {
       .option('o', {
         alias:    'outdir',
         type:     'string',
-        describe: 'Path to save submission code',
+        describe: 'Where to save submission code',
         default:  '.'
       })
       .option('x', {