This command is part of the [TclX] package.
    :   '''system''' ''cmdstr1'' ?''cmdstr2 ...''?
Concatenates ''cmdstr1'', ''cmdstr2'' etc. with space separators (see the [concat] command) into a single command and then evaluates the command using the standard system shell. On Unix systems, this is `/bin/sh` and on Windows it is `command.com` or `cmd.exe` (depending on version). The exit code of the command is returned.

This command differs from the [exec] command in that system doesn't return the executed command's standard output as the result string (instead, it returns a return code of the command that was executed), and system goes through the Unix shell to provide wildcard expansion, redirection, etc, as is normal from an [sh] command line.

One example is:
======
$ tclsh8.5
% package require Tclx
8.4
% system fgrep lvirden /etc/motd
1
% exec fgrep lvirden /etc/motd
child process exited abnormally
% set rc [system fgrep Sun /etc/motd]
Sun Microsystems Inc.   SunOS 5.8       Generic Patch   December 2002
% puts $rc
0
%
======

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%| [Category Command] | [Category TclX] |%
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