is there any way (what is the easiest way in bash) to combine the following:
mkdir foo
cd foo
The manpage for mkdir does not describe anything like that, maybe there is a fancy version of mkdir? I know that cd has to be shell builtin, so the same would be true for the fancy mkdir...
Aliasing?
I think creating a function is the most appropriate way to do this, but just for listing all alternative ways, you could write:
mkdir foo && cd "$_"
$_is a special parameter that holds the last argument of the previous command. The quote around $_ make sure it works even if the folder name contains spaces.
In some shells, such as zsh, the double quotes surrounding the $_ are not necessary even when the directory name contains spaces. They are required for this command to work in bash, however.
For example, running this command in bash 3.2.57 on macOS 10.13.6:
mkdir "my directory" && cd $_
results in this output:
bash: cd: my: No such file or directory
However, if we surround $_ with double quotes, the command returns successfully.
bash-3.2$ mkdir "my directory" && cd "$_"
bash-3.2$ echo $?
0
bash-3.2$
$!, in this case, is !#:1. i.e. "$_" can be replaced with !#:1.
– antak
Dec 07 '16 at 05:33
bash --norc, but when config is active then echo $_ echoes $_, while echo ${_} works. I couldn't find the reason.
Probably ${_} is more safe variation and should be used in the answer?
– MarSoft
Feb 02 '17 at 22:18
--norc, this command echo abc; echo def; echo $_ echoes abc def $_ (each on new line). When using --norc, the same command yields abc def def (each on new line).
– MarSoft
Feb 02 '17 at 22:23
bash? It works for me under bash 4.3.46 whether if I supply --norc or not. I would be curious to see what your bashrc looks like if it works when starting the shell without config, even though I don't think you can modify special parameters like _.
– Zajn
Feb 02 '17 at 23:18
git-prompt script. Yet to determine how does it achieve such behaviour :) Probably any PROMPT_COMMAND will influence the $_?
– MarSoft
Feb 06 '17 at 17:58
$_'s value will be foo in this example. If I had instead typed mkdir workspace, the value of $_ would have been workspace, and cd "$_" would change our current directory to the newly created workspace. Does that make sense?
– Zajn
Feb 23 '17 at 15:56
bash. I've tried it in zsh and confirmed that it works without the double quotes, but since the question was tagged with bash, I answered accordingly.
– Zajn
Aug 10 '17 at 03:03
mkdir "test folder" && cd $_ in bash and see the result. I should have specified in my last comment that this pertains to directories with spaces in their names.
– Zajn
Aug 10 '17 at 03:09
bash when creating a directory that contains spaces. Since the question is tagged for bash, I answered accordingly.
– Zajn
Oct 02 '18 at 18:52
bash: cd: my: No such file or directory. I mean, it shows that the cd is being invoked and my is the argument but pwd && mkdir thisdir && cd $_ && pwd demonstrates the point without an error. All the same, TIL about the $_ command. Thanks!
– harperville
Jan 15 '19 at 20:01
$_ in certain shells, namely bash. Perhaps I should re-word that section to more clearly state that without the "$_", that is the error you will see.
– Zajn
Jan 15 '19 at 20:52
Function?
mkcdir ()
{
mkdir -p -- "$1" &&
cd -P -- "$1"
}
Put the above code in the ~/.bashrc, ~/.zshrc or another file sourced by your shell. Then source it by running e.g. source ~/.bashrc to apply changes.
After that simply run mkcdir foo or mkcdir "nested/path/in quotes".
Notes:
"$1" is the first argument of the mkcdir command. Quotes around it protects the argument if it has spaces or other special characters.-- makes sure the passed name for the new directory is not interpreted as an option to mkdir or cd, giving the opportunity to create a directory that starts with - or --.-p used on mkdir makes it create extra directories if they do not exist yet, and -P used makes cd resolve symbolic links.source-ing the rc, you may also restart the terminal emulator/shell.
-- is used to make sure that the following parameters are not parsed as a options to modify the behaviour of the command. In this case it makes sure the passed name for the new directory is not interpreted as an option to mkdir or cd, giving the option to create a directory that starts with - or -- .
– immeëmosol
Jan 04 '17 at 11:12
-P used makes cd resolve symbol links. The -p used on mkdir makes it create extra directories if they do not exists yet.
– immeëmosol
Jan 04 '17 at 11:14
export <name_of_my_function>. Thensource ~/.bashrc` or restart terminal, and the function will be available as a command. I really think the comments should be integrated into the answer, but I don't want to intrude to someone else's answer.
– Asotos
Mar 24 '18 at 10:26
|| exit following the cd?
e.g. mkdir -p -- "$1" && cd -P -- "$1" || exit
take defined, so you can use something like take somenewdir . The function looks like this: take () { mkdir -p $@ && cd ${@:$#} }
– qwertz
Jun 09 '21 at 10:06
Bash (using word designators):
/tmp/bug$ mkdir "some dir"
/tmp/bug$ cd !$
cd "some dir"
/tmp/bug/some dir$
!$ expands to the last argument of the previous line in the history. If you have parameters in between, then you can use !:1 for the first argument, !:2 forthe second argument, etc.
From bash(1):
Event Designators
An event designator is a reference to a command line entry in the history list. Unless the reference is absolute, events are relative to the current position in the history list.
!Start a history substitution, except when followed by a blank, newline, carriage return,=or((when the extglob shell option is enabled using the shopt builtin).[..]
Word Designators
Word designators are used to select desired words from the event. A
:separates the event specification from the word designator. [..][..]
n The n-th word.
^The first argument. That is, word 1.
$The last word. This is usually the last argument, but will expand to the zeroth word if there is only one word in the line.
!:1, but it is an option if you have a path with a non-unique prefix.
– Lekensteyn
Apr 18 '14 at 14:34
!$ is shorter and easier to type on many keyboards. See also <Alt-.> or <Alt-_>
– Stéphane Chazelas
Apr 18 '14 at 14:51
!$ instead.
– Lekensteyn
Apr 18 '14 at 15:06
These other lads are just making life complicated, here it is:
eval {mkdir,cd}\ FOLDER\;
'FOLDER && rm ../something'. But eval won't let me :*( Tragically, may have to choose complicated in the battle of complicated vs evil.
–
Apr 19 '14 at 02:14
eval with user input is generally a bad idea and eval will process FOLDER && rm ../something in place of FOLDER without complaint. Or for another variant, how about "FOLDER && rm -r $HOME"
–
Apr 19 '14 at 17:28
eval with user input, so it's fine. Don't cargo cult.
– mrr
Jan 30 '16 at 06:56
FOLDER, sure, this is fine. That's not the point, if you use it with variable input (which you almost certainly are going to), the results for weird directory names can at best cause unexpected results, at worst pose a security risk.
–
Feb 01 '16 at 01:36