Version 0.4.0: Add script which.py

[ppu.git] / ppu / find_executable.py

diff --git a/ppu/find_executable.py b/ppu/find_executable.py
new file mode 100755 (executable)
index 0000000..0c4720c
--- /dev/null
+++ b/ppu/find_executable.py
@@ -0,0 +1,48 @@
+#!/usr/bin/env python
+
+
+# https://gist.github.com/4368898
+# Public domain code by anatoly techtonik <techtonik@gmail.com>
+# AKA Linux `which` and Windows `where`
+
+
+import os
+import sys
+
+
+def find_executable(executable, path=None):
+    """Find if 'executable' can be run. Looks for it in 'path'
+    (string that lists directories separated by 'os.pathsep';
+    defaults to os.environ['PATH']). Checks for all executable
+    extensions. Returns full path or None if no command is found.
+    """
+    if path is None:
+        path = os.environ['PATH']
+    paths = path.split(os.pathsep)
+    extlist = ['']
+    if os.name == 'os2':
+        (base, ext) = os.path.splitext(executable)
+        # executable files on OS/2 can have an arbitrary extension, but
+        # .exe is automatically appended if no dot is present in the name
+        if not ext:
+            executable = executable + ".exe"
+    elif sys.platform == 'win32':
+        pathext = os.environ['PATHEXT'].lower().split(os.pathsep)
+        (base, ext) = os.path.splitext(executable)
+        if ext.lower() not in pathext:
+            extlist = pathext
+    for ext in extlist:
+        execname = executable + ext
+        if os.path.isfile(execname):
+            return execname
+        else:
+            for p in paths:
+                f = os.path.join(p, execname)
+                if os.path.isfile(f):
+                    return f
+    else:
+        return None
+
+
+if __name__ == '__main__':
+    print(find_executable('git'))