spiralofhope

Projects > Bash >

The results were moved into mcd.sh, with compatibility with Dash.

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I went through a whole lot of hell to try to figure out how to make and change into a directory. My simple 4DOS mini-script wasn’t properly translating to Bash, and I didn’t understand why. So I posted this:

I’m trying to create a simple script to md + cd into a directory.

It’s much more difficult than I expect.

First, I learn that I can’t do something trivial like this.

cat > ~/script.sh
md $1
cd $1
# press control-d
chmod +x script.sh
~/script.sh

.. but this I already knew. I tried working with an alias, but I can’t figure out how to use $1 twice or how to spit out two commands with one alias.

i.e. this stuff won’t work:

alias mcd='md $1 ; cd $1'
alias mcd='md {$1} ; cd {$1}'

but even if I do this:

alias mcd='echo $1 ; echo $1'

then $1 is only usable once.

mcd testing
# => testing

Then I tried to step back and have my md+cd in a script.

I make a script which spits out the commands, like this:

cat > ~/mcd.sh
echo md $1
echo cd $1
# press control-d
chmod +x script.sh

and then I make an alias like this:

alias mcd='eval $(~/mcd.sh)'

and I run it like:

mcd testing

but this will only evaluate the first expression in ~/script.sh which makes the testing directory (but does not cd into it)

I guess my question is:

How can I make an alias do two things?

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The answer?

Either:

mcd() {
  mkdir "$1"
  cd "$1"
}

or:

mcd() { mkdir "$1" ; cd "$1" ; }