6.8. Ruby environment variable

发布时间 :2023-10-24 23:00:07 UTC      

The Ruby interpreter uses the following environment variables to control its behavior. The ENV object contains a list of all currently set environment variables.

Variable

Description

DLN_LIBRARY_PATH

Dynamically loads the path that the module searches for.

HOME

The directory to move to when no parameters are passed to Dir::chdir. Also used in File::expand_path to extend “~”.

LOGDIR

The directory to move to when no parameters are passed to Dir::chdir and the environment variable HOME is not set.

PATH

Execute the search path for the child process, and the search path for the Ruby program after the-S option is specified. Each path is separated by a colon (semicolon in DOS and Windows).

RUBYLIB

The search path to the library. Each path is separated by a colon (semicolonin DOS and Windows).

RUBYLIB_PREFIX

Used to modify the RUBYLIB search path, replacing the library prefix path1 with path2 by using the format path1;path2 or path1path2.

RUBYOPT

Command line options passed to the Ruby interpreter. Ignored in taint mode (where $SAFE is greater than 0).

RUBYPATH

The search path of the Ruby program after the-S option is specified. Priority is higher than PATH. Ignored in taint mode (where $SAFE is greater than 0).

RUBYSHELL

Specifies the shell to be used when executing the command. If the environment variable is not set, SHELL or COMSPEC is used.

For Unix, use the env command to view a list of all environment variables.

HOSTNAME=ip-72-167-112-17.ip.secureserver.net
RUBYPATH=/usr/bin
SHELL=/bin/bash
TERM=xterm
HISTSIZE=1000
SSH_CLIENT=122.169.131.179 1742 22
SSH_TTY=/dev/pts/1
USER=amrood
JRE_HOME=/usr/java/jdk/jre
J2RE_HOME=/usr/java/jdk/jre
PATH=/usr/local/bin:/bin:/usr/bin:/home/guest/bin
MAIL=/var/spool/mail/guest
PWD=/home/amrood
INPUTRC=/etc/inputrc
JAVA_HOME=/usr/java/jdk
LANG=C
HOME=/root
SHLVL=2
JDK_HOME=/usr/java/jdk
LOGDIR=/usr/log/ruby
LOGNAME=amrood
SSH_CONNECTION=122.169.131.179 1742 72.167.112.17 22
LESSOPEN=|/usr/bin/lesspipe.sh %s
RUBYLIB=/usr/lib/ruby
G_BROKEN_FILENAMES=1
_=/bin/env

Principles, Technologies, and Methods of Geographic Information Systems  102

In recent years, Geographic Information Systems (GIS) have undergone rapid development in both theoretical and practical dimensions. GIS has been widely applied for modeling and decision-making support across various fields such as urban management, regional planning, and environmental remediation, establishing geographic information as a vital component of the information era. The introduction of the “Digital Earth” concept has further accelerated the advancement of GIS, which serves as its technical foundation. Concurrently, scholars have been dedicated to theoretical research in areas like spatial cognition, spatial data uncertainty, and the formalization of spatial relationships. This reflects the dual nature of GIS as both an applied technology and an academic discipline, with the two aspects forming a mutually reinforcing cycle of progress.