add dependency checks for #225

dotdrop/dotdrop.py

@@ -16,7 +16,7 @@ from dotdrop.installer import Installer
 from dotdrop.updater import Updater
 from dotdrop.comparator import Comparator
 from dotdrop.utils import get_tmpdir, remove, strip_home, \
-    run, uniq_list, patch_ignores
+    run, uniq_list, patch_ignores, dependencies_met
 from dotdrop.linktypes import LinkTypes
 from dotdrop.exceptions import YamlException
 
@@ -648,6 +648,13 @@ def main():
     if o.debug:
         LOG.dbg('\n\n')
 
+    # check dependencies are met
+    try:
+        dependencies_met()
+    except Exception as e:
+        LOG.err(e)
+        return False
+
     ret = True
     try:
 

dotdrop/utils.py

@@ -12,7 +12,7 @@ import uuid
 import fnmatch
 import inspect
 import importlib
-from shutil import rmtree
+from shutil import rmtree, which
 
 # local import
 from dotdrop.logger import Logger
@@ -224,3 +224,12 @@ def get_module_from_path(path):
     loader = importlib.machinery.SourceFileLoader(module_name, path)
     mod = loader.load_module()
     return mod
+
+
+def dependencies_met():
+    """make sure all dependencies are met"""
+    deps = ['file', 'diff', 'mkdir', 'cp']
+    err = 'The tool \"{}\" was not found in the PATH!'
+    for dep in deps:
+        if not which(dep):
+            raise Exception(err.format(dep))