I have very little experience working with bash. With that being said I need to create a bash script that takes your current directory path and saves it to a shell variable. I then need to be able to type "echo $shellvariable" and have that output the directory that I saved to that variable in the bash script. This is what I have so far.
#!/bin/bash
mypath=$(pwd)
cd $1
echo $mypath
exec bash
now when I go to command line and type "echo $mypath" it outputs nothing.
You can just run source <file_with_your_vars>, this will load your variables in yours script or command line session.
> cat source_vars.sh
my_var="value_of_my_var"
> echo $my_var
> source source_vars.sh
> echo $my_var
value_of_my_var
. (yes, a period is a valid command), but some shells like bash allow source as a synonym (with some subtle differences).'env -i' gives control what vars a shell/programm get...
#!/bin/bash
mypath=$(pwd)
cd $1
echo $mypath
env -i mypath=${mypath} exec bash
...i.e. with minimal environment.
You have to export the variable for it to exist in the newly-execed shell:
#!/bin/bash
export mypath=$(pwd)
cd $1
echo $mypath
exec bash
export is not strictly necessary. One can also do mypath=$(pwd) exec bash.I don't know if you need to start a new shell every time you run a script, don't recommend this.
I think the better solution is using source instead of bash.
Example:
$ cat script.sh
#!/bin/bash
mypath=$(pwd)
cd $1
echo $mypath
To run it: source script.sh
Now, this will update your terminal and add this variable without starting a new process.
execturns that subprocess into a new interactive shell). That new shell will be missing any (non-exported) variables from the original shell (along with any special modes set in that shell). If you run the script five times, you'll wind up 5 levels deep in subprocesses. Then, as you exit those shells it'll drop back to the parent shells one level by one. This is probably not what you want.