Ubuntu – create a new script and chmod it in one command

bashcommand line

When writing answers on here, it's often necessary to create a new script and chmod +x it to make it executable. I won't go into whether this is a good thing or not, but explaining to people that they need to fire in three separate command (and teaching them to use nano!) is a bit of a waffle.

Is there anything easier?

Best Answer

Why yes there is! Let me introduce you to the install command. install is a GNU-standard application that lets you copy files around and specify certain things at the same time. The short syntax is install SOURCE DESTINATION.

However, "certain things" are important. You can specify the file mode with -m xxx (755 for writeable by owner and executable by anyone). And bash has a couple of tricks for redirecting new files and here-doc for accepting long-form data. Here's a quick example:

install -b -m 755 /dev/stdin ~/testbin << EOF
#!/bin/sh
echo "Success!"
EOF

Now you can run ~/testbin and it should echo out.

You can combine this with sudo for root-owned files or if you want to write as somebody else, you can sudo and use install's -o owner flag.

The -b flag just creates a backup if you run the command a second time. This is helpful if you're doing potentially destructive tasks.

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Although Radu's answer is absolutely correct, I feel like it's a bit incomplete for the beginner that does not know the location of certain files, so here's a step-by-step on the second method (using ~/bin). If you would like to store the files somewhere else than ~/bin, follow step 1, otherwise, ignore it and keep in mind you'll be using ~/bin as your scripts folders.

Open a terminal and run the following:
```
nano .profile
```
You should see, at the end of the file:
```
# set PATH so it includes user's private bin if it exists
if [ -d "$HOME/bin" ] ; then
    PATH="$HOME/bin:$PATH"
fi
```
If you don't see it, try using nano .bash_profile instead. Keep in mind you should be at ~/, that is, /home/YOUR_USERNAME

This tells bash where user's scripts are. The default is /home/YOUR_USERNAME/bin which is "abbreviated" as $HOME/bin or ~/bin. You can then change it to any folder you'd like to store your scripts in. Mine is ~/.bin -- the same as the original, but hidden.
If you already issued chmod +x script.sh just move your scripts to the folder in which you're going to store them - create it if it doesn't exist. Inside that folder, if you store your scripts as file.sh you'll have to run file.sh everytime, so store them as file -- no extensions.

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