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50 lines
1.8 KiB
TeX
50 lines
1.8 KiB
TeX
\section{Standard module \sectcode{commands}} % If implemented in Python
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\label{module-commands}
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\stmodindex{commands}
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The \code{commands} module contains wrapper functions for \code{os.popen()}
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which take a system command as a string and return any output generated by
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the command, and optionally, the exit status.
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The \code{commands} module is only usable on systems which support
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\code{popen()} (currently \UNIX{}).
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The \code{commands} module defines the following functions:
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\renewcommand{\indexsubitem}{(in module commands)}
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\begin{funcdesc}{getstatusoutput}{cmd}
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Execute the string \var{cmd} in a shell with \code{os.popen()} and return
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a 2-tuple (status, output). \var{cmd} is actually run as
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\samp{\{\ cmd \} ; 2$>$\$1}, so that the returned output will contain output
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or error messages. A trailing newline is stripped from the output.
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The exit status for the command can be interpreted according to the
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rules for the \C{} function \code{wait()}.
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\end{funcdesc}
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\begin{funcdesc}{getoutput}{cmd}
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Like \code{getstatusoutput()}, except the exit status is ignored and
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the return value is a string containing the command's output.
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\end{funcdesc}
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\begin{funcdesc}{getstatus}{file}
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Return the output of \samp{ls -ld \var{file}} as a string. This
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function uses the \code{getoutput()} function, and properly escapes
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backslashes and dollar signs in the argument.
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\end{funcdesc}
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Example:
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\begin{verbatim}
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>>> import commands
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>>> commands.getstatusoutput('ls /bin/ls')
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(0, '/bin/ls')
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>>> commands.getstatusoutput('cat /bin/junk')
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(256, 'cat: /bin/junk: No such file or directory')
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>>> commands.getstatusoutput('/bin/junk')
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(256, 'sh: /bin/junk: not found')
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>>> commands.getoutput('ls /bin/ls')
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'/bin/ls'
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>>> commands.getstatus('/bin/ls')
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'-rwxr-xr-x 1 root 13352 Oct 14 1994 /bin/ls'
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\end{verbatim}
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