OpenBSD sh and ksh differences?

UNIX BSD
1

Hi,

I am running OpenBSD 3.7, my first attempt with this OS. I noticed that both /bin/sh and /bin/ksh are both really the pdksh. Yet each has its own manpage. I was wondering what are the differences b/w the two programs on OpenBSD. I.e., has the team configured pdksh to function one way if invoked as "ksh", while functionning differntly if invoked as "sh". (Compare GHU bash, which behaves slightly differntly when invoked as "sh".)

Thanks,

2

See the table in this artice UNIX shell differences and how to change your shell (Monthly Posting)

3

That's not what I was after. But I did find this in OpenBSD's sh man page:

So it indeed does function like bash, insofar that OpenBSD's modified version of pdksh checks if it has been invoked as "sh" or as "ksh", and adjusts accordingly. The only thing now is determning what presicely are those features that are disabled from their pdksh when it is invoked as sh. They should list them in the man page, but in fact they don't. One feature difference that I have spotted so far is that "sh" mode that does not support (( )) style arithmetic; you have to us let. (Though $(( )) arithmeatic expansion does work in "sh".)

4

Indeed, here is a snippet OpenBSD's code (@ http://www.openbsd.org/cgi-bin/cvsweb/src/bin/ksh/main.c\):