Source code for commands

"""Execute shell commands via os.popen() and return status, output.

Interface summary:

       import commands

       outtext = commands.getoutput(cmd)
       (exitstatus, outtext) = commands.getstatusoutput(cmd)
       outtext = commands.getstatus(file)  # returns output of "ls -ld file"

A trailing newline is removed from the output string.

Encapsulates the basic operation:

      pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r')
      text = pipe.read()
      sts = pipe.close()

 [Note:  it would be nice to add functions to interpret the exit status.]
"""
from warnings import warnpy3k
warnpy3k("the commands module has been removed in Python 3.0; "
         "use the subprocess module instead", stacklevel=2)
del warnpy3k

__all__ = ["getstatusoutput","getoutput","getstatus"]

# Module 'commands'
#
# Various tools for executing commands and looking at their output and status.
#
# NB This only works (and is only relevant) for UNIX.


# Get 'ls -l' status for an object into a string
#
[docs]def getstatus(file): """Return output of "ls -ld <file>" in a string.""" import warnings warnings.warn("commands.getstatus() is deprecated", DeprecationWarning, 2) return getoutput('ls -ld' + mkarg(file))
# Get the output from a shell command into a string. # The exit status is ignored; a trailing newline is stripped. # Assume the command will work with '{ ... ; } 2>&1' around it.. #
[docs]def getoutput(cmd): """Return output (stdout or stderr) of executing cmd in a shell.""" return getstatusoutput(cmd)[1]
# Ditto but preserving the exit status. # Returns a pair (sts, output) #
[docs]def getstatusoutput(cmd): """Return (status, output) of executing cmd in a shell.""" import os pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r') text = pipe.read() sts = pipe.close() if sts is None: sts = 0 if text[-1:] == '\n': text = text[:-1] return sts, text
# Make command argument from directory and pathname (prefix space, add quotes). #
[docs]def mk2arg(head, x): import os return mkarg(os.path.join(head, x))
# Make a shell command argument from a string. # Return a string beginning with a space followed by a shell-quoted # version of the argument. # Two strategies: enclose in single quotes if it contains none; # otherwise, enclose in double quotes and prefix quotable characters # with backslash. #
[docs]def mkarg(x): if '\'' not in x: return ' \'' + x + '\'' s = ' "' for c in x: if c in '\\$"`': s = s + '\\' s = s + c s = s + '"' return s