/bin/true (was [TUHS] basic tools / Universal Unix)

Steffen Nurpmeso steffen at sdaoden.eu
Fri Oct 20 07:23:53 AEST 2017


Mr. Ron Natalie,

"Ron Natalie" <ron at ronnatalie.com> wrote:
 |My favorite reduction to absurdity was /bin/true.   Someone decided we
 |needed shell commands for true and false.   Easy enough to add a script that
 |said "exit 0" or exit 1" as its only line.
 |Then someone realized that the "exit 0" in /bin true was superfluous, the
 |default return was 0.  /bin/true turned into an empty, yet executable, file.

i am actively chewing on this.
These things can be found by the exec family of C functions,
as Chet Ramey points out from time to time (but i think on other
lists).  That even makes things which make no sense but as
a shell builtin a little bit understandable... maybe..
I for one am ever so fascinated of Unix!
I cannot remember what i thought once entering the Unix world,
i remember i first did not understand why and that [ etc. do exist.

 |Then the lawyers got involved.    We got a version of a packaged UNIX (I
 |think it was Interactive Systems).    Every shell script got twelve lines of
 |copyright/license boilerplate.     Including /bin true.
 |The file had nothing but useless comment in it.

Yes.  But then nonetheless quite the opposite, it was very strange
looking at Plan9 source code which does not have such a file
header, after living in the world of BSD and GNU source code for
one and a half decade.  Different to your experience, for me the
lawyers were there first.

--steffen
|
|Der Kragenbaer,                The moon bear,
|der holt sich munter           he cheerfully and one by one
|einen nach dem anderen runter  wa.ks himself off
|(By Robert Gernhardt)


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