In BASH, I use "pushd . " command to save the current directory on the stack. After issuing this command in couple of different directories, I have multiple directories saved on the stack which I am able to see by issuing command "dirs". For example, the output of "dirs" command in my current bash session is given below -
0 ~/eclipse/src
1 ~/eclipse
2 ~/parboil/src
Now, to switch to 0th directory, I issue a command "cd ~0". I want to create a bash alias command or a function for this command. Something like "xya 0", which will switch to 0th directory on stack. I wrote following function to achieve this -
xya(){
cd ~$1
}
Where "$1" in above function, is the first argument passed to the function "xya".
But, I am getting the following error -
-bash: cd: ~1: No such file or directory
Can you please tell what is going wrong here ?
Generally, bash parsing happens in the following order:
Thus, by the time your parameter is expanded, tilde expansion is already finished and will not take place again, without doing something explicit like use of eval
.
If you know the risks and are willing to accept them, use eval
to force parsing to restart at the beginning after the expansion of $1
is complete. The below tries to mitigate the damage should something that isn't eval
-safe is passed as an argument:
xya() {
local cmd
printf -v cmd 'cd ~%q' "$1"
eval "$cmd"
}
...or, less cautiously (which is to say that the below trusts your arguments to be eval
-safe):
xya() {
eval "cd ~$1"
}