Linux/windows View SET environment variable directives

First, Linux:

1. View instructions for all environment variables

Method 1:$:export (Export command is to display, set, or delete Linux environment variables ;)

Method 2:$:env

2. View a specified environment variable

Method 1:$:export PATH

Method 2:$:echo $PATH

3. Modify the settings for an environment variable:

1) temporarily modify an environment variable, the next time after power-on invalid

Method A:$:echo "xxx to append content xxxx" >> $PATH

Method B:$:export path= "xxx to modify the content of XXXX"

Method c:$: Export path= $PATH:/usr/xxxx The path to append ( where colon is a delimiter between directories )

Method d:$: path= "xxx to modify the content of XXXX"

2) Add path to/etc/profile, this method permanently modifies an environment variable for all users

$: Export path= $PATH:/usr/xxxx The path to append (where colons are delimiters between directories)

$: Sourcr/etc/profile

3) Add path to the current ~/.bash_profile, which is permanently active for the current user. Similar to the second step, replace the profile with Bash_profile.

$: Export path= $PATH:/usr/xxxx The path to append (where colons are delimiters between directories)

$: Source ~/.bash_profile

Second, window: (The use of set is similar to the use of export in Linux, but in Windows it is not the $ variable name, but the% variable name%)

1. View instructions for all environment variables

$:set (the SET command is to display, set, or delete Windows environment variables ;)

2. View a specified environment variable

Method a:$:P Ath (directly enter an environment variable name, Eg:path)

Method B:$:echo%Path%

Method C:$:set%Path%

3. Modify the settings for an environment variable:

Third, Linux will add instructions to start the boot

Add the instructions in the/etc/rc.local

1	/usr/local/webserver/mongodb/bin/mongod --dbpath=/data0/mongodb/data --logpath=/data0/mongodb/logs --logappend  --port=27017

Similarities and differences between 3,/etc/rc.local and/etc/rc.d/

The/etc/rc.local script is executed after the system initialization level script runs, so you can safely add scripts that you want to execute after the system starts. The/etc/rc.local is connected to the/etc/rc.d/rc.local soft connection and is actually a thing.

The/etc/rc.d/directory contains many system startup and stop scripts for various services, which control all kinds of transactions from Acpid to X11-common, similar to the registry for Windows. The contents of the/etc/rc.d/directory are as follows:

(1) init.d/: Binary files directory for various servers and programs.
(2) rcx.d/: The Executing program connection directory at each boot level. Everything inside is a soft connection pointing to the init.d/. Specific behind the narration.
(3) There are three more scripts: Rc.sysinit, RC, rc.local.

Linux/windows View SET environment variable directives