diff --git a/lua-npge-dev-1.rockspec b/lua-npge-dev-1.rockspec
index 29014b5..bc2d850 100644
--- a/lua-npge-dev-1.rockspec
+++ b/lua-npge-dev-1.rockspec
@@ -67,7 +67,9 @@ build = {
         ['npge.util.trim'] = 'src/npge/util/trim.lua',
         ['npge.util.unique'] = 'src/npge/util/unique.lua',
         ['npge.util.unpack'] = 'src/npge/util/unpack.lua',
+        ['npge.util.execute'] = 'src/npge/util/execute.lua',
         ['npge.util.writeIt'] = 'src/npge/util/writeIt.lua',
+        ['npge.util.writeFile'] = 'src/npge/util/writeFile.lua',
         ['npge.util.threads'] = 'src/npge/util/threads.lua',
         ['npge.util.mapItems'] = 'src/npge/util/mapItems.lua',
         ['npge.util.textToIt'] = 'src/npge/util/textToIt.lua',
diff --git a/spec/util/execute_spec.lua b/spec/util/execute_spec.lua
new file mode 100644
index 0000000..a7e8f2c
--- /dev/null
+++ b/spec/util/execute_spec.lua
@@ -0,0 +1,17 @@
+-- lua-npge, Nucleotide PanGenome explorer (Lua module)
+-- Copyright (C) 2014-2016 Boris Nagaev
+-- See the LICENSE file for terms of use.
+
+describe("npge.util.execute", function()
+    it("executes a program", function()
+        local tmpName = require 'npge.util.tmpName'
+        local tmp_fname = tmpName()
+        os.remove(tmp_fname)
+        local nullName = require 'npge.util.nullName'
+        local cmd = ('mkdir %s 2> %s'):format(tmp_fname, nullName())
+        local execute = require 'npge.util.execute'
+        assert.truthy(execute(cmd))
+        assert.falsy(execute(cmd))
+        os.remove(tmp_fname)
+    end)
+end)
diff --git a/spec/util/writeFile_spec.lua b/spec/util/writeFile_spec.lua
new file mode 100644
index 0000000..0b6f770
--- /dev/null
+++ b/spec/util/writeFile_spec.lua
@@ -0,0 +1,15 @@
+-- lua-npge, Nucleotide PanGenome explorer (Lua module)
+-- Copyright (C) 2014-2016 Boris Nagaev
+-- See the LICENSE file for terms of use.
+
+describe("npge.util.writeFile", function()
+    it("writes string to file", function()
+        local writeFile = require 'npge.util.writeFile'
+        local tmpName = require 'npge.util.tmpName'
+        local tmp_fname = tmpName()
+        writeFile(tmp_fname, "42")
+        local readFile = require 'npge.util.readFile'
+        assert.equal(readFile(tmp_fname), "42")
+        os.remove(tmp_fname)
+    end)
+end)
diff --git a/src/npge/util/execute.lua b/src/npge/util/execute.lua
new file mode 100644
index 0000000..246f93a
--- /dev/null
+++ b/src/npge/util/execute.lua
@@ -0,0 +1,12 @@
+-- lua-npge, Nucleotide PanGenome explorer (Lua module)
+-- Copyright (C) 2014-2016 Boris Nagaev
+-- See the LICENSE file for terms of use.
+
+return function(cmd)
+    if _VERSION == 'Lua 5.1' then
+        return os.execute(cmd) == 0
+    else
+        -- Lua >= 5.2
+        return os.execute(cmd)
+    end
+end
diff --git a/src/npge/util/init.lua b/src/npge/util/init.lua
index d8997b6..3d6f66f 100644
--- a/src/npge/util/init.lua
+++ b/src/npge/util/init.lua
@@ -5,6 +5,7 @@
 return {
     split = require 'npge.util.split',
     unpack = require 'npge.util.unpack',
+    execute = require 'npge.util.execute',
     loadstring = require 'npge.util.loadstring',
     arraysEqual = require 'npge.util.arraysEqual',
     arraysLess = require 'npge.util.arraysLess',
@@ -19,6 +20,7 @@ return {
     endsWith = require 'npge.util.endsWith',
     trim = require 'npge.util.trim',
     writeIt = require 'npge.util.writeIt',
+    writeFile = require 'npge.util.writeFile',
     fileExists = require 'npge.util.fileExists',
     sandbox = require 'npge.util.sandbox',
     readFile = require 'npge.util.readFile',
diff --git a/src/npge/util/writeFile.lua b/src/npge/util/writeFile.lua
new file mode 100644
index 0000000..175fd0c
--- /dev/null
+++ b/src/npge/util/writeFile.lua
@@ -0,0 +1,9 @@
+-- lua-npge, Nucleotide PanGenome explorer (Lua module)
+-- Copyright (C) 2014-2016 Boris Nagaev
+-- See the LICENSE file for terms of use.
+
+return function(fname, text)
+    local f = io.open(fname, 'w')
+    f:write(text)
+    f:close()
+end