I seem to recall csh was semi-case-insensitive, another reason to stay away.
'PATH' is hard coded into exec(), the library path variable whatever it is on the brand in the synamic linker, MANPATH into man, and '$PWD' changes no matter how you change the working directory, so the environment has many frozen variables. I checked my local CScope web utility. Lots of include files mention PATH, but none has "PATH" -- maybe in the kernel C?
Hi!
How-to get the environment variables in GNU.
getenv() only fetches the ones that you can find under export (not the ones under declare)...
best regars .David (2 Replies)
hi,
1). i would like to know what is meant by environment variables?
2). is the number of envi variables is a constant number for unix systems?
3). how to see the list of envi variables (and the values of the envi variables)in a single command?
4). if this questions were already asked... (3 Replies)
hi,
I want to create a new EV(Environment Variable) through a c program and I done this thing through setenv() method. But the newly created EV is not permanent, i.e. when I exit from the program the EV also no longer lives. But I want to make it a permanent EV for the current user. Actually I... (6 Replies)
I have read tons of posts about how you can't set persisting environment variable in a child script of a shell and have it persist. The only way is to source a file as
% . <scriptname>
I am finding that true... but I know there is a way around it. I just don't know how. I worked for 6... (5 Replies)
Hi Experts,
Need your help in understanding the commands to setup the environment variables in hp-ux.
Beleive need to use either set,setenv or export.
I am confused between above three options, when to use which option?
On command line, I have tried both set and setenv but couldn't... (1 Reply)
1. The problem statement:
What is the mesg value set for your environment? If it is on, how would you turn off your current
session? How would you set it permanently?
3. The attempts at a solution :
Read Unix The textbook.
3rd chapter has many things like environment variables and... (5 Replies)
Hi All,
I need to understand following three environment variables and their usages in HP Unix.
_M_ARENA_OPTS
_M_CACHE_OPTS
PTHREAD_SCOPE_SYSTEM
How does these environment variables influence multi threaded applciation and how do we decide the value of these variables? Is there... (0 Replies)
Discussion started by: angshuman
0 Replies
LEARN ABOUT CENTOS
env
Env(3) User Contributed Perl Documentation Env(3)NAME
Env - perl module that imports environment variables as scalars or arrays
SYNOPSIS
use Env;
use Env qw(PATH HOME TERM);
use Env qw($SHELL @LD_LIBRARY_PATH);
DESCRIPTION
Perl maintains environment variables in a special hash named %ENV. For when this access method is inconvenient, the Perl module "Env"
allows environment variables to be treated as scalar or array variables.
The "Env::import()" function ties environment variables with suitable names to global Perl variables with the same names. By default it
ties all existing environment variables ("keys %ENV") to scalars. If the "import" function receives arguments, it takes them to be a list
of variables to tie; it's okay if they don't yet exist. The scalar type prefix '$' is inferred for any element of this list not prefixed by
'$' or '@'. Arrays are implemented in terms of "split" and "join", using $Config::Config{path_sep} as the delimiter.
After an environment variable is tied, merely use it like a normal variable. You may access its value
@path = split(/:/, $PATH);
print join("
", @LD_LIBRARY_PATH), "
";
or modify it
$PATH .= ":.";
push @LD_LIBRARY_PATH, $dir;
however you'd like. Bear in mind, however, that each access to a tied array variable requires splitting the environment variable's string
anew.
The code:
use Env qw(@PATH);
push @PATH, '.';
is equivalent to:
use Env qw(PATH);
$PATH .= ":.";
except that if $ENV{PATH} started out empty, the second approach leaves it with the (odd) value "":."", but the first approach leaves it
with ""."".
To remove a tied environment variable from the environment, assign it the undefined value
undef $PATH;
undef @LD_LIBRARY_PATH;
LIMITATIONS
On VMS systems, arrays tied to environment variables are read-only. Attempting to change anything will cause a warning.
AUTHOR
Chip Salzenberg <chip@fin.uucp> and Gregor N. Purdy <gregor@focusresearch.com>
perl v5.16.3 2013-03-02 Env(3)