Adding method get_command() to class PpApplication

diff --git a/pp_lib/app.py b/pp_lib/app.py
index f63ed9c1a796350c65e4ae86e45967fdfe9adc76..1fe1172c6956ec1375ab3ea0e2f6426df3aa60f2 100644 (file)
--- a/pp_lib/app.py
+++ b/pp_lib/app.py
@@ -28,12 +28,13 @@ from .global_version import __version__ as __global_version__
 from .errors import FunctionNotImplementedError, PpAppError
 
 from .common import pp, terminal_can_colors, to_bytes
+from .common import caller_search_path
 
 from .colored import ColoredFormatter, colorstr
 
 from .obj import PpBaseObjectError, PpBaseObject
 
-__version__ = '0.3.2'
+__version__ = '0.3.3'
 LOG = logging.getLogger(__name__)
 
 
@@ -743,6 +744,61 @@ class PpApplication(PpBaseObject):
             return msg
         return colorstr(msg, color)
 
+    # -------------------------------------------------------------------------
+    def get_command(self, cmd, quiet=False):
+        """
+        Searches the OS search path for the given command and gives back the
+        normalized position of this command.
+        If the command is given as an absolute path, it check the existence
+        of this command.
+
+        @param cmd: the command to search
+        @type cmd: str
+        @param quiet: No warning message, if the command could not be found,
+                      only a debug message
+        @type quiet: bool
+
+        @return: normalized complete path of this command, or None,
+                 if not found
+        @rtype: str or None
+
+        """
+
+        if self.verbose > 2:
+            LOG.debug("Searching for command {!r} ...".format(cmd))
+
+        # Checking an absolute path
+        if os.path.isabs(cmd):
+            if not os.path.exists(cmd):
+                LOG.warning("Command {!r} doesn't exists.".format(cmd))
+                return None
+            if not os.access(cmd, os.X_OK):
+                msg = "Command {!r} is not executable.".format(cmd)
+                LOG.warning(msg)
+                return None
+            return os.path.normpath(cmd)
+
+        # Checking a relative path
+        for d in caller_search_path():
+            if self.verbose > 3:
+                LOG.debug("Searching command in {!r} ...".format(d))
+            p = os.path.join(d, cmd)
+            if os.path.exists(p):
+                if self.verbose > 2:
+                    LOG.debug("Found {!r} ...".format(p))
+                if os.access(p, os.X_OK):
+                    return os.path.normpath(p)
+                else:
+                    LOG.debug("Command {!r} is not executable.".format(p))
+
+        # command not found, sorry
+        if quiet:
+            if self.verbose > 2:
+                LOG.debug("Command {!r} not found.".format(cmd))
+        else:
+            LOG.warning("Command {!r} not found.".format(cmd))
+
+        return None
 
 # =============================================================================