Create file and its parent directory

touch is not able to create directories, you need mkdir for that.

However, mkdir has the useful -p/--parents option which creates a full directory structure.

From man mkdir:

   -p, --parents
          no error if existing, make parent directories as needed

So the command you need in your specific situation is:

mkdir -p ~/Desktop/a/b/c/d/e/f/g/h/ && touch ~/Desktop/a/b/c/d/e/f/g/h/1.txt

If you think you will need this more often and don't want to type the path twice every time, you can also make a Bash function or a script for it.

• Bash function (append this line to ~/.bashrc to persitently have it available to your user, otherwise it will vanish again when you exit your terminal):

  touch2() { mkdir -p "$(dirname "$1")" && touch "$1" ; }
  

  It can be simply used like this:

  touch2 ~/Desktop/a/b/c/d/e/f/g/h/1.txt
  

• Bash script (store it in /usr/local/bin/touch2 using sudo to make it available for all users, else in ~/bin/touch2 for your user only):

  #!/bin/bash
  mkdir -p "$(dirname "$1")" &&
      touch "$1"
  

  Don't forget to make the script executable using chmod +x /PATH/TO/touch2.

  After that you can also run it like this:

  touch2 ~/Desktop/a/b/c/d/e/f/g/h/1.txt
  

One can use install command with -D flag.

bash-4.3$ install -D /dev/null mydir/one/two

bash-4.3$ tree mydir
mydir
└── one
    └── two

1 directory, 1 file
bash-4.3$ 

If we have multiple files, we might want to consider using a list of items(note, remember to quote items with spaces), and iterating over them:

bash-4.3$ for i in mydir/{'subdir one'/{file1,file2},'subdir 2'/{file3,file4}} ; do 
> install -D /dev/null "$i"
> done
bash-4.3$ tree mydir
mydir
├── one
│   └── two
├── subdir 2
│   ├── file3
│   └── file4
└── subdir one
    ├── file1
    └── file2

Or alternatively with array:

bash-4.3$ arr=( mydir/{'subdir one'/{file1,file2},'subdir 2'/{file3,file4}} )
bash-4.3$ for i in "${arr[@]}"; do  install -D /dev/null "$i"; done
bash-4.3$ tree mydir
mydir
├── one
│   └── two
├── subdir 2
│   ├── file3
│   └── file4
└── subdir one
    ├── file1
    └── file2

mkdir -p parent/child && touch $_/file.txt