Combining commands in bash script

[rossoreed]

I'm creating a rc.local script to create directories, empty files & permissions in a tmpfs volume, and found that I've got each command on a separate line.
Is there a way I can combine commands, similar to:
$ sudo mkdir /var/log/{redis,apache2,mysql}
(I tried that and it didn't work!)

sudo mkdir /var/log/redis
sudo mkdir /var/log/apache2
sudo mkdir /var/log/mysql
sudo touch /var/log/redis/redis-server.log
sudo touch /var/log/emoncms.log
sudo touch /var/log/mysql.log
sudo chmod 666 /var/log/redis/redis-server.log
sudo chmod 740 /var/log/apache2
sudo chmod 666 /var/log/emoncms.log
sudo chmod 666 /var/log/mysql/error.log
sudo chmod 666 /var/log/mysql.log
...and so on...

[DirkS]

Something like

Code: Select all

for i in "redis" "apache2" "mysql" ; do mkdir /var/log/"$i"; done

Double quotes should only be necessary if there are spaces in the values

[QuietZone]

The underlying point to this is that rc.local (and similar) gets executed via "/bin/sh", which is actually bash masquerading as "old/standard" sh. The brace expansion trick only works in bash (and some other shells, having originally appeared as part of csh). When bash is running in "sh mode", it doesn't recognize brace expansion.

The solutions are (in order of preference):

1) Re-write things so as not to use brace expansion.

2) Arrange for your code to be run via "bash", not "sh".

[DougieLawson]

Jessie runs it with this service file

Code: Select all

[Unit]
Description=/etc/rc.local Compatibility
ConditionFileIsExecutable=/etc/rc.local
After=network-online.target

[Service]
Type=forking
ExecStart=/etc/rc.local start
TimeoutSec=0
RemainAfterExit=yes
SysVStartPriority=99

so that mean rc.local runs with whatever shell is defined in the shebang line. Change that and you can run rc.local with bash.

[rossoreed]

Well Dirk 'S answer seems to work OK, but it seemed to get very blurred thereafter!

In (very) basic terminology, is Dirk's reply the way to go?

[rossoreed]

What if the command requires a value, such as 'chown mysql:adm' or requires sudo to execute?
I don't seem to get that working despite putting the command within double quotes ""sudo chown mysql:adm""

Paul

[DougieLawson]

A chown command isn't the sort of command you'd run at EVERY boot. Do it once and it's sticky.

If you insist on doing it in /etc/rc.local
/bin/chown mysql:adm /var/mysql/file.to.change.ownership
You do NOT need sudo, because rc.local is running with root privileges any way.

[rpdom]

A chown command isn't the sort of command you'd run at EVERY boot. Do it once and it's sticky.

However the OP is doing it to set up a tmpfs which will be empty after every boot.

I'm creating a rc.local script to create directories, empty files & permissions in a tmpfs volume

In this particular case it does need to by run at every boot. I agree it's not the usual case though.
.

[DougieLawson]

The mount options for his tmpfs must be wrong. Change those rather than mucking about with chown.

[rossoreed]

Tmpfs appears to mount ok, but the issues are that MYSQL expects to find the /var/log/mysql folder structure and also it's mysql.log & error.log files. If they are not present, MySQL cannot create them and errors. Same applies with Redis.
I want to get the logs into tmpfs to extend the life of a system which runs on a SD card, and can be subject to power outages.
It does work ok if I simply list the commands, each to a line, but I'm trying to combine commands, similar to the way suggested above by DirkS, however I'm not sure of the format when combining chown or chmod commands, as they have a value too.

[DougieLawson]

You can change those mysql directories in /etc/mysql/my.cnf

[rossoreed]

Yes I'm aware of that, but as I want the logs to be in tmpfs, I would still need to create empty log files with the correct permissions set for MySQL to write to, as it can't create them itself. Same with Redis.