How to run 'cd' in shell script and stay t

问题:

I used 'change directory' in my shell script (bash)

#!/bin/bash
alias mycd='cd some_place'
mycd
pwd

pwd prints some_place correctly, but after the script finished my current working directory doesn't change.

Is it possible to change my path by script?

回答1:

You need to source the file as:

. myfile.sh

or

source myfile.sh

Without sourcing the changes will happen in the sub-shell and not in the parent shell which is invoking the script. But when you source a file the lines in the file are executed as if they were typed at the command line.

回答2:

The script is run in a separate subshell. That subshell changes directory, not the shell you run it in. A possible solution is to source the script instead of running it:

# Bash
source yourscript.sh
# or POSIX sh
. yourscript.sh

回答3:

While sourcing the script you want to run is one solution, you should be aware that this script then can directly modify the environment of your current shell. Also it is not possible to pass arguments anymore.

Another way to do, is to implement your script as a function in bash.

function cdbm() {
    cd whereever_you_want_to_go
     echo arguments to the functions were $1, $2, ...
}

This technique is used by autojump: http://github.com/joelthelion/autojump/wiki to provide you with learning shell directory bookmarks.

回答4:

It can be achieved by sourcing. Sourcing is basically execute the script in the same shell whereas normal execution(sh test.sh or ./test.sh) will create sub shell and execute script there.

test.sh

cd development/
ls
# Do whatever you want.

Execute test.sh by

source test.sh

. is shortest notation for source. So you can also do by

. test.sh

This will execute the script and change the directory of current shell to development/.

回答5:

whenever you run a script on your login shell, a new subprocess is spawned and the script execution is done in a subshell.Once the script completes, the subshell exits and you are returned to the login shell.Hence whenever you do a cd through a script,the directory is changed to the path specified by cd, but by the time script finishes you come back to your login shell to the working directory from where you started the script.

The way to overcome this is use,

source yourscript.sh

what source does is it executes the script as TCL script, i.e it has the same effect as when you typed each line on the command line of your login shell and it executed from there. So this way when the script finishes after cd , it stays in that directory.