[trimming the cc a bit] On 08/03/2010 03:21 PM, Mikael Magnusson wrote: >> But it is _also_ a bug in zsh; adding zsh-workers accordingly. >> >> $ zsh -cvx 'f=" val" e=; echo "$e"$f' >> +zsh:1> f=' val' e='' >> +zsh:1> echo ' val' >> val >> >> Oops - zsh only passed one argument to echo, with a leading space, >> instead of passing an empty argument and letting echo supply the space. >> ksh93, pdksh, and dash get it right (although dash doesn't use quotes >> in -vx output, hence my use of n() to force things to tell; n() is >> another way to expose the bash and zsh bugs). > > zsh doesn't do word splitting by default, you can enable it with the = modifier: > % zsh -fcvx 'f=" val" e=; echo "$e"$=f' > +zsh:1> f=' val' e='' > +zsh:1> echo '' val > val > > does what you want Thanks for the information. > > Alternatively you can make zsh try to be closer to sh by setting > argv[0] to sh when executing it, or running 'emulate sh' as the first > command (and possibly other ways I don't know about): > % zsh -fcvx 'emulate sh;f=" val" e=; echo "$e"$f' > +zsh:1> emulate sh > +zsh:1> f=' val' e='' > +zsh:1> echo '' val > val In the context of portable shell programming, and autoconf in particular, we already _always_ force zsh into 'emulate sh' mode, so that we don't trip up on non-POSIX incompatibilities like this behavior of word splitting. So it should not be a problem for autoconf, other than to remind users that portable programming requires the use of 'emulate sh' in scripts that don't pick up autoconf's automatic shell sanitization prelude. -- Eric Blake eblake@xxxxxxxxxx +1-801-349-2682 Libvirt virtualization library http://libvirt.org
Attachment:
signature.asc
Description: OpenPGP digital signature