"""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.]
"""

__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
#
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..
#
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)
#
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).
#
def mk2arg(head, x):
from warnings import warnpy3k
warnpy3k("In 3.x, mk2arg has been removed.")
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.
#
def mkarg(x):
from warnings import warnpy3k
warnpy3k("in 3.x, mkarg has been removed.")
if '\'' not in x:
return ' \'' + x + '\''
s = ' "'
for c in x:
if c in '\\$"`':
s = s + '\\'
s = s + c
s = s + '"'
return s