54 lines
1.8 KiB
TeX
54 lines
1.8 KiB
TeX
\section{\module{commands} ---
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Utilities for running commands}
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\declaremodule{standard}{commands}
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\platform{Unix}
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\modulesynopsis{Utility functions for running external commands.}
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\sectionauthor{Sue Williams}{sbw@provis.com}
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The \module{commands} module contains wrapper functions for
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\function{os.popen()} which take a system command as a string and
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return any output generated by the command and, optionally, the exit
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status.
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The \module{commands} module defines the following functions:
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\begin{funcdesc}{getstatusoutput}{cmd}
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Execute the string \var{cmd} in a shell with \function{os.popen()} and
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return a 2-tuple \code{(\var{status}, \var{output})}. \var{cmd} is
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actually run as \code{\{ \var{cmd} ; \} 2>\&1}, so that the returned
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output will contain output or error messages. A trailing newline is
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stripped from the output. The exit status for the command can be
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interpreted according to the rules for the C function
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\cfunction{wait()}.
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\end{funcdesc}
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\begin{funcdesc}{getoutput}{cmd}
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Like \function{getstatusoutput()}, except the exit status is ignored
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and 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 \function{getoutput()} function, and properly
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escapes 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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