Re: alias for commands broken in bash 2.05.0

[Paul Jarc]

"Noel L Yap" <yap_noel@jpmorgan.com> writes:
> What does ${1+"$@"} do?  Or, better yet, can you point me to a URL
> or info file that describes it?

In the case of bash, it's the same as "$@".  But some other shells
expand "$@" to "" (a single empty string) when there are no arguments;
all shells expand ${1+"$@"} to nothing when there are no arguments, so
it's a good habit to get into.  From the bash man page:
       bash tests for a parameter that is unset or null; omitting the
       colon results in a test only for a parameter that is unset.
...
       ${parameter:+word}
              Use  Alternate  Value.   If  parameter  is  null or
              unset, nothing is substituted, otherwise the expan­
              sion of word is substituted.

So if $1 is set (possibly empty), you get "$@"; otherwise, you get
nothing.


paul