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author Guido van Rossum <guido@python.org>
date Thu, 17 Jul 1997 16:29:42 +0000
parents 6a218fa8ba9b
children e16994f3d102
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c29fc17d8e4f Documentation for Lib/commands.py, from Sue Williams.
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1 \section{Standard module \sectcode{commands}} % If implemented in Python
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2 \stmodindex{commands}
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3
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4 The \code{commands} module contains wrapper functions for \code{os.popen()}
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5 which take a system command as a string and return any output generated by
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6 the command, and optionally, the exit status.
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7
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8 The \code{commands} module is only usable on systems which support
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9 \code{popen()} (currently \UNIX{}).
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11 The \code{commands} module defines the following functions:
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12
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13 \renewcommand{\indexsubitem}{(in module commands)}
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14 \begin{funcdesc}{getstatusoutput}{cmd}
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15 Execute the string \var{cmd} in a shell with \code{os.popen()} and return
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16 a 2-tuple (status, output). \var{cmd} is actually run as
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6a218fa8ba9b Fix LaTeX bug found by examining the docstrings added to commands.py.
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17 \samp{\{\ cmd \} ; 2$>$\$1}, so that the returned output will contain output
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18 or error messages. A trailing newline is stripped from the output.
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19 The exit status for the command can be interpreted according to the
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20 rules for the \C{} function \code{wait()}.
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21 \end{funcdesc}
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22
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23 \begin{funcdesc}{getoutput}{cmd}
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24 Like \code{getstatusoutput()}, except the exit status is ignored and
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25 the return value is a string containing the command's output.
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26 \end{funcdesc}
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27
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28 \begin{funcdesc}{getstatus}{file}
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29 Return the output of \samp{ls -ld \var{file}} as a string. This
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30 function uses the \code{getoutput()} function, and properly escapes
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31 backslashes and dollar signs in the argument.
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32 \end{funcdesc}
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33
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34 Example:
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35
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36 \begin{verbatim}
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37 >>> import commands
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38 >>> commands.getstatusoutput('ls /bin/ls')
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39 (0, '/bin/ls')
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40 >>> commands.getstatusoutput('cat /bin/junk')
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41 (256, 'cat: /bin/junk: No such file or directory')
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42 >>> commands.getstatusoutput('/bin/junk')
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43 (256, 'sh: /bin/junk: not found')
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44 >>> commands.getoutput('ls /bin/ls')
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45 '/bin/ls'
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46 >>> commands.getstatus('/bin/ls')
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47 '-rwxr-xr-x 1 root 13352 Oct 14 1994 /bin/ls'
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48 \end{verbatim}