Regid Ichira writes:
> I am a perl beginner. I stambled upon a perl line
>
> if (system("command -v wget >/dev/null 2>&1") == 0)
>
>I was able to find perl's documentation for system. But where is
>the documentation for command?
The command, command is a shell builtin. On Debian you can find
information about it in:
$ man 7 builtins
or
$ man 7 bash-builtins.
If you install man posix manpages:
$ sudo apt-get install manpages-posix manpages-posix-dev
You should find further information about it under
$ man 1p command
> Am I right that that line tests whether wget is installed in the
>system? How does it do that?
- From the man page:
``The command utility shall cause the shell to treat the arguments as a
simple command, suppressing the shell function lookup that is described
in Command Search and Execution, item 1b.''
So, basically it will run the wget, ignoring some shell functions
and builtins. This is used often as a security measure.
/mek
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