How to run a new shell with copy of current shell declarations?

Shell Programming and Scripting
1

How to run another shell and have all current shell dectaration copied to that new shell?

I would like to have available all current declarations in a new shell. That are functions, aliases, variables.

I need to test some functions that use the 'exit', but running it in current shell on 'exit' will close the shell, which I do not like.

2 
# export thing=hello
# echo $thing
hello
# bash
# echo $thing
hello
#

I don't see the problem...

3

I had a similar issue recently and found that I could use the "return" command and it wouldn't kill my session.
ex:
return 10

This is under ksh.

4

The problem is:
The only EXPORTED variables are copyed.
I need many functions and declared not exported variables.
I am running functions which change and define variables.
Some of them need to be run in separate process, in '()': like >(funct_boo)
I do not want redeclare all functions, aliases and variables in the new process

src> alias boo="echo boo-boo"
src> foo()
> {
> echo "foo from func";
> }
src> foo
foo from func
src> boo
boo-boo
src> var=variable
src> echo $var
variable
src> hm
dca0701> bash
executing file .bashrc - starting the bash shell--
----> Start of the .myset file  <---
----> End   of the .myset file  <---
src> foo
bash: foo: command not found
src> boo
bash: boo: command not found
src> echo $var

src>

The return() I have used, but it is not cover my situation.
There is a stack of functions, if somewhere something has not-0-return I need to stop execution of all stacked function, but do not kill the shell.
Return works only for one function.

Is any other possibility exist?

5

Still have no idea how to do it.
Is it possible to run another shell and have all FUNCTIONS and ALIASES from current shell be available in new one?

6

bash has an -a option to automatically export all variables and functions, dunno if this is a bashism but I would guess it's POSIX. Try "set -a" at the top of the script.

In bash, it seems you can't export aliases. All the more reason to use functions instead of aliases.

7

Thank you, ERA, for advise, but I could not have it work.
Not sure where 'set -a' should be used:

  • in original shell, where function and variables are defined and where new shell is started
  • whith start shell command, like : >bash -a
  • in new shell after starting

I have tried all 3 way but do not have any success.

--193:/home/dca0701/develop/src> alias boo="echo boo-boo"
--193:/home/dca0701/develop/src> foo()
> { echo "foo from func";  }
--195:/home/dca0701/develop/src> var=variable
--195:/home/dca0701/develop/src> ec $var; boo; foo
variable
boo-boo
foo from func


--196:/home/dca0701/develop/src> bash -a
executing file .bashrc - starting the bash shell--

----> Start of the .myset file  <---
----> End   of the .myset file  <---
--193:/home/dca0701/develop/src> ec $var; boo; foo

bash: boo: command not found
bash: foo: command not found
--193:/home/dca0701/develop/src> exit


--197:/home/dca0701/develop/src> set -a
--198:/home/dca0701/develop/src> bash
executing file .bashrc - starting the bash shell--

----> Start of the .myset file  <---
----> End   of the .myset file  <---
--193:/home/dca0701/develop/src> ec $var; boo; foo

bash: boo: command not found
bash: foo: command not found
--193:/home/dca0701/develop/src> exit


--199:/home/dca0701/develop/src>
--199:/home/dca0701/develop/src>
--202:/home/dca0701/develop/src> bash
executing file .bashrc - starting the bash shell--

----> Start of the .myset file  <---
----> End   of the .myset file  <---
--194:/home/dca0701/develop/src> set -a
--195:/home/dca0701/develop/src> ec $var; boo; foo

bash: boo: command not found
bash: foo: command not found
--196:/home/dca0701/develop/src>
8

Possible but not easily done. Think about it, opens up all sorts of security issues.

BTW, most test suites use a combination of TCL and expect to test shell scripts.

9

How about:

$ declare > my_declarations
$ bash
$ source my_declarations

I'm not sure that's what you're looking for, but it might work... dunno

*EDIT:
no... don't even bother... declare doesn't store alias declarations

10

Works for me, but I guess you will have to set -a before you declare the ones you want exported.

vnix$ PS1='nst> '
nst> set -a
nst> fnord=foo
nst> foo () { echo foo; }
nst> alias bar='echo bar'
nst> bash
vnix$ echo "$fnord"
foo
vnix$ foo
foo
vnix$ bar
bash: bar: command not found
vnix$ exit
nst> exit