export vs env vs set commands

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Operating Systems Solaris export vs env vs set commands
# 1  
Old 06-18-2011
export vs env vs set commands


I'm trying to understand variable scopes in solaris10.
It is said that to display env variables we use 3 commands :
- env
- set
- export

What is the difference between them ?

thx for help.

---------- Post updated at 11:00 AM ---------- Previous update was at 10:50 AM ----------

I understand this :

To list all shell vars with their current values perform set cmd.
# set


To make a value of variable known to a subshell export it using the export cmd.
# export
export LOGNAME
export PATH
export REMOTE

Now I understand the difference between set and export cmds but don't understand the meaning of env command ?
What does it mean to make a value of variable known to a sub-shell ?

Last edited by presul; 06-18-2011 at 08:06 AM..
# 2  
Old 06-18-2011
Originally Posted by presul
What does it mean to make a value of variable known to a sub-shell ?
[root@linux ~]# x=5                       <= here variable is set without export command
[root@linux ~]# echo $x
[root@linux ~]# bash                      <= subshell creation
[root@linux ~]# echo $x                   <= subshell doesnt know $x variable value

[root@linux ~]# exit                      <= exit from subshell
[root@linux ~]# echo $x                   <= parent shell still knows $x variable
[root@linux ~]# export x=5                <= specify $x variable value using export command
[root@linux ~]# echo $x                   <= parent shell doesn't see any difference from the first declaration
[root@linux ~]# bash                      <= create subshell again
[root@linux ~]# echo $x                   <= now the subshell knows $x variable value
[root@linux ~]#

# 3  
Old 06-18-2011
ok @bartus11 I understand now the difference but have one more question :

Command set shows all declared variables, command export shows only declared and exported variables but what shows env command ?
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