"Compile" script with command line

[pedrommone]

I have a bash script like this one



#!/bin/bash

SERVER_ID=1
SERVER_NAME="Brazil-1"
SERVER_IP="123.213.123.123"
SERVER_TYPE="Privado"

// do stuff

I want to run other script called make-config.sh, it should "compile" the first script variables (set them) like this command


make-config.sh -server_id 123 server_name "name" server_ip = "123.123.123.123" server_type = "private"

The problem is that I have no idea of how do it, someone can share some tutorials about that? Thanks.

[r-senior]

Do you need to use long options, i.e. "make-config --serverid=xyz" or would short options suffice, e.g. "make-config -s xyz"?

[schragge]

You can use getopt (http://manpages.ubuntu.com/manpages/precise/en/man1/getopt.1.html) and a here-document (http://www.gnu.org/software/bash/manual/html_node/Redirections.html#Here-Documents) for it


cat <<END >~/compiled-script.bash
#!/bin/bash

SERVER_ID=$server_id
SERVER_NAME=$server_name
SERVER_IP=$server_ip
SERVER_TYPE=$server_type
END

[pedrommone]

Do you need to use long options, i.e. "make-config --serverid=xyz" or would short options suffice, e.g. "make-config -s xyz"?

Doesnt matter they size, I just want know how to do it.


You can use getopt (http://manpages.ubuntu.com/manpages/precise/en/man1/getopt.1.html) and a here-document (http://www.gnu.org/software/bash/manual/html_node/Redirections.html#Here-Documents) for it


cat <<END >~/compiled-script.bash
#!/bin/bash

SERVER_ID=$server_id
SERVER_NAME=$server_name
SERVER_IP=$server_ip
SERVER_TYPE=$server_type
END


For real, didnt get how to use it.

[r-senior]

If short options are OK, you can use the Bash getopts builtin:

http://wiki.bash-hackers.org/howto/getopts_tutorial

If you need long options, you can use the getopt program, as suggested by schragge. Here's an example: http://software.frodo.looijaard.name/getopt/docs/getopt-parse.bash

I haven't checked that either of these examples work.

[pedrommone]

If short options are OK, you can use the Bash getopts builtin:

http://wiki.bash-hackers.org/howto/getopts_tutorial

If you need long options, you can use the getopt program, as suggested by schragge. Here's an example: http://software.frodo.looijaard.name/getopt/docs/getopt-parse.bash

I haven't checked that either of these examples work.

But, how to save them into compiled-bash.sh?

[steeldriver]

You could have your getopt script create a file that exports the variables, and then source it from your other script, e.g.


$ server_id=1; server_type="Privado"
$
$ cat > servervars <<EOF
export SERVER_ID="$server_id"
export SERVER_TYPE="$server_type"
EOF
$
$ echo $SERVER_ID $SERVER_TYPE

$
$ source servervars
$ echo $SERVER_ID $SERVER_TYPE
1 Privado
$

FWIW you should probably avoid using ALL_CAPS names though as these are traditionally reserved for system variables

[schragge]

This is just a minimal example. Better check the manual page of getopt and study the example script linked by r-senior above to understand how getopt works.


script="compiled-bash.sh"
temp=`getopt -l id:,name:,address:,type: -n "$0" -- '' "$@"` || exit 1
eval set -- optname optval "$temp"
declare -A opt
while shift 2; do
case $1 in
--id|--name|--address|--type) opt[${1#--}]="$2";;
esac
done
cat <<EOF >"$script"
#!/bin/bash

SERVER_ID=${opt[id]}
SERVER_NAME=${opt[name]}
SERVER_IP=${opt[address]}
SERVER_TYPE=${opt[type]}
EOF

[pedrommone]

This is just a minimal example. Better check the manual page of getopt and study the example script linked by r-senior above to understand how getopt works.


script="compiled-bash.sh"
temp=`getopt -l id:,name:,address:,type: -n "$script" -- '' "$@"` || exit 1
eval set -- optname optval "$temp"
declare -A opt
while shift 2; do
case $1 in
--id|--name|--address|--type) opt[${1#--}]="$2";;
esac
done
cat <<EOF >"$script"
#!/bin/bash

SERVER_ID=${opt[id]}
SERVER_NAME=${opt[name]}
SERVER_IP=${opt[address]}
SERVER_TYPE=${opt[type]}
EOF


I should call it using compiler.sh --id or --name? If the script already exists, it will override it?

[schragge]

Yep. E.g.
./compiler.sh --id=1 --name 'Brazil-1' --address 1.2.3.4 --type="Privado"

[pedrommone]

Yep. E.g.
./compiler.sh --id=1 --name 'Brazil-1' --address 1.2.3.4 --type="Privado"

It will override if already exists?

[schragge]

Yes, it will overwrite the old file contents unless you put set -C or set -o noclobber before it.

[pedrommone]

Ok, thanks buddy!

[pedrommone]

It is giving one error


compile-tunnel.sh: 5: compile-tunnel.sh: declare: not found

[schragge]

Well, declare is a bash-specific builtin. Is compile-tunnel.sh a /bin/sh script? Then you cannot use associative arrays in it.

[pedrommone]

No, is bash script

[schragge]

Then you either source it from a /bin/sh script or invoke it with sh compile-tunnel.sh The error message you get is not from bash, it's from dash.

[r-senior]

The error message you get is not from bash, it's from dash.
@pedrommone: It's quite common on Debian-based systems for people to write scripts with this shebang line at the top:


#!/bin/sh

or launch them with /bin/sh and still believe they are running a Bash script because Bash is the default shell used by the terminal (/bin/bash is the shell added to /etc/passwd by default when a new user is created). But if you look at /bin/sh on a Debian-based system, including Ubuntu, you'll see that /bin/sh is linked to /bin/dash, which is the "(D)ebian (A)lmquist (Sh)ell ("https://en.wikipedia.org/wiki/Debian_Almquist_shell).


$ ls -l /bin/sh
lrwxrwxrwx 1 root root 4 Mar 29 2012 /bin/sh -> dash

So you need to take care to ensure you are invoking a Bash script if you intend to use Bash-specifics, e.g.:


#!/bin/bash

[pedrommone]

I was using sh when callling the script, now I dont 'compile' mysql commands like this one


USER_TIME=$(mysql -u $DB_USER -p$DB_PASS -h$DB_HOST $DB_NAME --disable-column-names -e "SELECT TIME_TO_SEC(TIMEDIFF(now(), online_users.updated_at)) FROM online_users WHERE user_id = $USER_ID ORDER BY updated_at ASC")

It execute them when I ran compile-tunnel.sh

[pedrommone]

How I can put my whole bash inside a 'string'? Cat is executing the script, I just want 'compile' it!