[lnst] ExecCmd: Adding new parameter to exec_cmd

[Jiří Pírko]

commit 3b5c8c08c2fee5c5817d25931fd970bbc6940cfb
Author: Radek Pazdera <rpazdera(a)redhat.com&gt;
Date:   Thu Oct 11 14:51:37 2012 +0200

    ExecCmd: Adding new parameter to exec_cmd
    
    This new boolean parameter allows the caller to specify whether
    to include the stderr output of the executed command in the exception
    that is thrown.
    
    Some commands have very nice and descriptive one-line error reports
    that LNST can pass along in the exception and print to user. On the
    other hand, some different commands print huge error reportings or
    memory dumps that definitely should not be printed to the user.
    
    Signed-off-by: Radek Pazdera <rpazdera(a)redhat.com&gt;

 Common/ExecCmd.py |   13 +++++++++----
 1 files changed, 9 insertions(+), 4 deletions(-)
---
diff --git a/Common/ExecCmd.py b/Common/ExecCmd.py
index 702ad73..174ea39 100644
--- a/Common/ExecCmd.py
+++ b/Common/ExecCmd.py
@@ -17,10 +17,12 @@ class ExecCmdFail(Exception):
     _cmd = None
     _retval = None
     _stderr = None
+    _report_stderr = None
 
-    def __init__(self, cmd=None, retval=None, err=""):
+    def __init__(self, cmd=None, retval=None, err="", report_stderr=False):
         self._stderr = err
         self._retval = retval
+        self._report_stderr = report_stderr
 
     def get_cmd(self):
         return self._cmd
@@ -30,9 +32,12 @@ class ExecCmdFail(Exception):
 
     def __str__(self):
         retval = ""
+        stderr = ""
         if self._retval:
             retval = " (exited with %d)" % self._retval
-        return "Command execution failed%s" % retval
+        if self._report_stderr:
+            stderr = " [%s]" % self._stderr
+        return "Command execution failed%s%s" % (retval, stderr)
 
 def log_output(log_func, out_type, out):
     log_func("%s:\n"
@@ -41,7 +46,7 @@ def log_output(log_func, out_type, out):
              "----------------------------"
              % (out_type, out))
 
-def exec_cmd(cmd, die_on_err=True, log_outputs=True):
+def exec_cmd(cmd, die_on_err=True, log_outputs=True, report_stderr=False):
     cmd = cmd.rstrip(" ")
     logging.debug("Executing: \"%s\"" % cmd)
     subp = subprocess.Popen(cmd, shell=True, stdout=subprocess.PIPE,
@@ -58,7 +63,7 @@ def exec_cmd(cmd, die_on_err=True, log_outputs=True):
         if data_stderr:
             log_output(logging.error, "Stderr", data_stderr)
     if subp.returncode and die_on_err:
-        err = ExecCmdFail(cmd, subp.returncode, data_stderr)
+        err = ExecCmdFail(cmd, subp.returncode, data_stderr,report_stderr)
         logging.error(err)
         raise err