Is it possible to have too many $PATHs set in OS X?
I've been learning about gems lately, and one error I get is:
WARNING: Installing to ~/.gem since /Library/Ruby/Gems/1.8 and
/usr/bin aren't both writable.
WARNING: You don't have /Users/Alex/.gem/ruby/1.8/bin in your PATH,
gem exec开发者_如何学运维utables will not run.
ERROR: Error installing rubygame:
ffi requires rake (>= 0.8.7, runtime)
I understand that UNIX (bash, more specifically) uses this .bash_profile file to know where to look for executables when I run a script/command, and that it does so "in order".
My question is: Can I just keep tacking directories on the end as I need them, and does doing this open me up to... anything?
(for what it's worth, I re-ran the command as "sudo gem..." and it still said "ERROR: Error installing rubygame:
ffi requires rake (>= 0.8.7, runtime)
)
You can add stuff to the end (or to the top) of PATH until you reach the length limit for a variable. Which is loooooong.
But it slows command searches. Every time you type a command the the executable is searched everywhere the PATH tells it to search until found. Commands typos may lead to non-existing files and those could get slow to sort out.
I believe bash caches the location of executables, so even if you have a long PATH it shouldn't take longer to run programs.
You could try sudo gem update rake
for that last error...
I don't know of any limits of how long the $PATH var or any one env var can be. But I guess there is a limit on environment variables in general, something like 65KB total. Still not sure.
精彩评论