10a8c90248264a8b26970b4473770bcc3df8515fJosh Gao"""Execute shell commands via os.popen() and return status, output.
20a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
30a8c90248264a8b26970b4473770bcc3df8515fJosh GaoInterface summary:
40a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
50a8c90248264a8b26970b4473770bcc3df8515fJosh Gao       import commands
60a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
70a8c90248264a8b26970b4473770bcc3df8515fJosh Gao       outtext = commands.getoutput(cmd)
80a8c90248264a8b26970b4473770bcc3df8515fJosh Gao       (exitstatus, outtext) = commands.getstatusoutput(cmd)
90a8c90248264a8b26970b4473770bcc3df8515fJosh Gao       outtext = commands.getstatus(file)  # returns output of "ls -ld file"
100a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
110a8c90248264a8b26970b4473770bcc3df8515fJosh GaoA trailing newline is removed from the output string.
120a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
130a8c90248264a8b26970b4473770bcc3df8515fJosh GaoEncapsulates the basic operation:
140a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
150a8c90248264a8b26970b4473770bcc3df8515fJosh Gao      pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r')
160a8c90248264a8b26970b4473770bcc3df8515fJosh Gao      text = pipe.read()
170a8c90248264a8b26970b4473770bcc3df8515fJosh Gao      sts = pipe.close()
180a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
190a8c90248264a8b26970b4473770bcc3df8515fJosh Gao [Note:  it would be nice to add functions to interpret the exit status.]
200a8c90248264a8b26970b4473770bcc3df8515fJosh Gao"""
210a8c90248264a8b26970b4473770bcc3df8515fJosh Gaofrom warnings import warnpy3k
220a8c90248264a8b26970b4473770bcc3df8515fJosh Gaowarnpy3k("the commands module has been removed in Python 3.0; "
230a8c90248264a8b26970b4473770bcc3df8515fJosh Gao         "use the subprocess module instead", stacklevel=2)
240a8c90248264a8b26970b4473770bcc3df8515fJosh Gaodel warnpy3k
250a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
260a8c90248264a8b26970b4473770bcc3df8515fJosh Gao__all__ = ["getstatusoutput","getoutput","getstatus"]
270a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
280a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Module 'commands'
290a8c90248264a8b26970b4473770bcc3df8515fJosh Gao#
300a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Various tools for executing commands and looking at their output and status.
310a8c90248264a8b26970b4473770bcc3df8515fJosh Gao#
320a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# NB This only works (and is only relevant) for UNIX.
330a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
340a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
350a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Get 'ls -l' status for an object into a string
360a8c90248264a8b26970b4473770bcc3df8515fJosh Gao#
370a8c90248264a8b26970b4473770bcc3df8515fJosh Gaodef getstatus(file):
380a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    """Return output of "ls -ld <file>" in a string."""
390a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    import warnings
400a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    warnings.warn("commands.getstatus() is deprecated", DeprecationWarning, 2)
410a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    return getoutput('ls -ld' + mkarg(file))
420a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
430a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
440a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Get the output from a shell command into a string.
450a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# The exit status is ignored; a trailing newline is stripped.
460a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Assume the command will work with '{ ... ; } 2>&1' around it..
470a8c90248264a8b26970b4473770bcc3df8515fJosh Gao#
480a8c90248264a8b26970b4473770bcc3df8515fJosh Gaodef getoutput(cmd):
490a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    """Return output (stdout or stderr) of executing cmd in a shell."""
500a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    return getstatusoutput(cmd)[1]
510a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
520a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
530a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Ditto but preserving the exit status.
540a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Returns a pair (sts, output)
550a8c90248264a8b26970b4473770bcc3df8515fJosh Gao#
560a8c90248264a8b26970b4473770bcc3df8515fJosh Gaodef getstatusoutput(cmd):
570a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    """Return (status, output) of executing cmd in a shell."""
580a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    import os
590a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    pipe = os.popen('{ ' + cmd + '; } 2>&1', 'r')
600a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    text = pipe.read()
610a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    sts = pipe.close()
620a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    if sts is None: sts = 0
630a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    if text[-1:] == '\n': text = text[:-1]
640a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    return sts, text
650a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
660a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
670a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Make command argument from directory and pathname (prefix space, add quotes).
680a8c90248264a8b26970b4473770bcc3df8515fJosh Gao#
690a8c90248264a8b26970b4473770bcc3df8515fJosh Gaodef mk2arg(head, x):
700a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    import os
710a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    return mkarg(os.path.join(head, x))
720a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
730a8c90248264a8b26970b4473770bcc3df8515fJosh Gao
740a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Make a shell command argument from a string.
750a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Return a string beginning with a space followed by a shell-quoted
760a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# version of the argument.
770a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# Two strategies: enclose in single quotes if it contains none;
780a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# otherwise, enclose in double quotes and prefix quotable characters
790a8c90248264a8b26970b4473770bcc3df8515fJosh Gao# with backslash.
800a8c90248264a8b26970b4473770bcc3df8515fJosh Gao#
810a8c90248264a8b26970b4473770bcc3df8515fJosh Gaodef mkarg(x):
820a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    if '\'' not in x:
830a8c90248264a8b26970b4473770bcc3df8515fJosh Gao        return ' \'' + x + '\''
840a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    s = ' "'
850a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    for c in x:
860a8c90248264a8b26970b4473770bcc3df8515fJosh Gao        if c in '\\$"`':
870a8c90248264a8b26970b4473770bcc3df8515fJosh Gao            s = s + '\\'
880a8c90248264a8b26970b4473770bcc3df8515fJosh Gao        s = s + c
890a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    s = s + '"'
900a8c90248264a8b26970b4473770bcc3df8515fJosh Gao    return s
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