1 \section{\module{commands} ---
2 Utilities for running commands}
4 \declaremodule{standard}{commands}
6 \modulesynopsis{Utility functions for running external commands.}
7 \sectionauthor{Sue Williams}{sbw@provis.com}
10 The \module{commands} module contains wrapper functions for
11 \function{os.popen()} which take a system command as a string and
12 return any output generated by the command and, optionally, the exit
15 The \module{subprocess} module provides more powerful facilities for
16 spawning new processes and retrieving their results. Using the
17 \module{subprocess} module is preferable to using the \module{commands}
20 The \module{commands} module defines the following functions:
23 \begin{funcdesc}{getstatusoutput}{cmd}
24 Execute the string \var{cmd} in a shell with \function{os.popen()} and
25 return a 2-tuple \code{(\var{status}, \var{output})}. \var{cmd} is
26 actually run as \code{\{ \var{cmd} ; \} 2>\&1}, so that the returned
27 output will contain output or error messages. A trailing newline is
28 stripped from the output. The exit status for the command can be
29 interpreted according to the rules for the C function
33 \begin{funcdesc}{getoutput}{cmd}
34 Like \function{getstatusoutput()}, except the exit status is ignored
35 and the return value is a string containing the command's output.
38 \begin{funcdesc}{getstatus}{file}
39 Return the output of \samp{ls -ld \var{file}} as a string. This
40 function uses the \function{getoutput()} function, and properly
41 escapes backslashes and dollar signs in the argument.
48 >>> commands.getstatusoutput('ls /bin/ls')
50 >>> commands.getstatusoutput('cat /bin/junk')
51 (256, 'cat: /bin/junk: No such file or directory')
52 >>> commands.getstatusoutput('/bin/junk')
53 (256, 'sh: /bin/junk: not found')
54 >>> commands.getoutput('ls /bin/ls')
56 >>> commands.getstatus('/bin/ls')
57 '-rwxr-xr-x 1 root 13352 Oct 14 1994 /bin/ls'
61 \seemodule{subprocess}{Module for spawning and managing subprocesses.}