4.4 /usr/bin : Most user commands #
4.4.1 Purpose #
This is the primary directory of executable commands on the system.
4.4.2 Requirements #
There must be no subdirectories in /usr/bin.
4.4.3 Specific Options #
The following files, or symbolic links to files, must be in
/usr/bin, if the corresponding subsystem is
installed:
| Command | Description |
|---|---|
perl | The Practical Extraction and Report Language (optional) |
python | The Python interpreted language (optional) |
tclsh | Simple shell containing Tcl interpreter (optional) |
wish | Simple Tcl/Tk windowing shell (optional) |
expect | Program for interactive dialog (optional) |
Tip: Rationale
In many executable scripts, the interpreter to be invoked to
execute the script is specified using
#!path_to_interpreter
on the first line of a script.
To make such scripts portable among different systems,
it is advantageous to standardize the interpreter locations.
The shell interpreter is already
fixed in /bin by this specification,
but interpreters for Perl, Python, Tcl and expect may be installed
in various places. The locations specified here may be implemented
as symbolic links to the physical location of the interpreters.