Trying to copy/paste long script with multiple EOFs, Terminal starts running half-way through

Question

Was trying to create a text block that I could just copy and paste into a Terminal window to accomplish something (in this case, create a systemd script to do maintenance on MySQL dbs, create a timer file to run that script weekly, and to enable the script).

When pasting it into a Terminal, it displays half of the script (up until the first EOF), prompts for the password through read, and then copies the typed password, along with the rest of the script in the spot where $pass is in the first file.

This is the block:

sudo sync && echo 'Enter MySQL password for Maintenance user' && read pass && sudo bash -s -c 'cat > "/usr/lib/systemd/system/db-m.service"' << "EOF"
[Service]
Type=oneshot
ExecStart='/usr/bin/mysqlcheck' --auto-repair --optimize --all-databases --force -u'maintenance' -p'$pass'
ExecStart='/usr/bin/sync'
EOF
sudo bash -c 'cat > "/usr/lib/systemd/system/db-m.timer"' << EOF
[Unit]
Description=Weekly database repair and maintenance

[Timer]
OnCalendar=weekly
Persistent=true

[Install]
WantedBy=timers.target
EOF
sudo systemctl daemon-reload && sudo systemctl enable 'db-m.timer' && sudo systemctl start 'db-m' 'db-m.timer' && sudo systemctl status 'db-m' -l

I recently added the "read pass" and the '$pass' variable that occurs 3 lines later; without those two things, I can copy and paste the entire block no problem.

Answer 1

The shell running in the terminal receives the script that you're pasting on its standard input, and your script itself reads from standard input. There's a conflict here: your script will end up reading a bit of itself.

If you don't get a sudo prompt, then what happens is:

1. The shell reads whole lines until it has a complete command. The first line starts a here document, so the shell keeps reading the here document.
2. When the shell reaches the first EOF line, it has a complete command, so it executes it.
3. sudo sync and `echo '…' run.
4. read pass runs. It reads a line of input, which is sudo bash -c …. This sets pass.
5. sudo sync runs.
6. The shell has finished executing the commands it had read, so it reads the next line of input which is [Unit].

Don't paste complex multiline shell code into a terminal. Instead, if you really need to run the clipboard content as a shell script, use xsel or xclip under X11, or pbpaste on OSX.

eval "`xsel`"
eval "`xclip`"
eval "`pbpaste`"

But really, what you should do is put this in a script, with #!/bin/sh at the top.