From: Jeffrey Schwab <jeff@...>
Date: 2006-10-06T02:50:08+09:00
Subject: Re: ENV shows partial environment only

ara.t.howard@noaa.gov wrote:
> On Thu, 5 Oct 2006, Eero Saynatkari wrote:
> 
>> Hi!
>>
>> It seems that Ruby is not picking up the complete environment
>> to be accessible through ENV--and I seem to recall this is by
>> design. Cursory poking-around in {hash,ruby,eval}.c did not
>> reveal anything particularly enlightening. Could someone shed
>> light on this if it indeed is done intentionally by Ruby and
>> not due to some strangeness in the C env functions?
>>
>> An example session:
>>
>> 18:28:43 ruerue@yawn > ruby -v
>> ruby 1.8.5 (2006-08-25) [amd64-freebsd6]
>>
>> 18:28:51 ruerue@yawn > set | ruby -e 'p ARGF.readlines.map {|l|
>> l.split("=").first if l =~ /^[A-Z]/}.compact'
>>
>> ["BASH", "BASH_ARGC", "BASH_ARGV", "BASH_LINENO", "BASH_SOURCE",
>> "BASH_VERSINFO", "BASH_VERSION", "BLOCKSIZE", "COLUMNS", "DIRSTACK",
>> "DISPLAY", "EDITOR", "EUID", "FTP_PASSIVE_MODE", "GROUPS", "HISTFILE",
>> "HISTFILESIZE", "HISTSIZE", "HOME", "HOSTNAME", "HOSTTYPE", "IFS",
>> "LINES", "LOGNAME", "MACHTYPE", "MAIL", "MAILCHECK", "OPTERR", "OPTIND",
>> "OSTYPE", "PATH", "PIPESTATUS", "PPID", "PR_BROWN", "PR_CLEAR",
>> "PR_LTGREY", "PS1", "PS2", "PS4", "PWD", "RS_EMAIL", "RS_NAME", "SHELL",
>> "SHELLOPTS", "SHLVL", "TERM", "TERMCAP", "UID", "USER", "WINDOWID",
>> "XAUTHORITY", "XTERM_SHELL", "XTERM_VERSION"]
>>
>> 18:28:54 ruerue@yawn > ruby -e 'p ENV.keys'
>>
>> ["SHELL", "TERM", "WINDOWID", "XTERM_SHELL", "RS_NAME", "USER",
>> "TERMCAP", "FTP_PASSIVE_MODE", "PATH", "MAIL", "BLOCKSIZE", "PWD",
>> "EDITOR", "XTERM_VERSION", "HOME", "SHLVL", "LOGNAME", "RS_EMAIL",
>> "DISPLAY", "XAUTHORITY", "_"]
> 
> it's been a while, but are you confusing shell vars with env vars?  i think
> 'set' only reports the former:
> 
>   harp:~ > export FOO=ENV_BAR
> 
>   harp:~ > set FOO=SHELL_BAR
> 
>   harp:~ > sh
> 
>   harp:~ > echo $FOO
>   ENV_BAR

You're using Bash/ksh syntax, but just so you know, the greater-than 
symbol (>) is usually reserved to mean csh or tcsh.  $ is the canonical 
non-root bash prompt.  Switching them up makes examples like this one a 
little confusing, and can be frustrating when you have to use someone 
else's machine for a second (e.g. to provide tech support through a VNC 
session) and some commands fail for no apparent reason.