[SOLVED] Bash script problem "No such file or directory"

Nominal Animal · 03-30-2011, 06:28 PM

(Check the commands in your previous post, please. I think you'll want to edit them.)

Quote:

Originally Posted by cnmoore

Code:

       STR="/bin/zcat '/home/mike/backups/$1' | /usr/bin/mysql -u username -p password '$2'"
       echo -e "$STR"
       eval "$STR"

Yes, that is what I meant. The issue is that now the mysql command part,

Quote:

Originally Posted by cnmoore

[CODE]
/usr/bin/mysql -u username -p password 'table'

fails. Have you made sure that the command

Code:

/bin/zcat '/home/mike/backups/mike_forum_110321-0100.sql.gz' | /usr/bin/mysql -u whoever -p xxxxxx 'test'

actually works?

cnmoore · 03-30-2011, 07:16 PM

Good question!

This works on command line:

Code:

/bin/gunzip <  /home/mike/backups/mike_forum_110321-0100.sql.gz |  /usr/bin/mysql -uGeorge -pxxxxx test

None of the variations introduced above work. Glad you asked!
Single quotes were in response to http://www.linuxquestions.org/questi...4/#post4308900

cnmoore · 03-30-2011, 08:08 PM

My son pointed out that even though echo -e "$STR" looks fine, $STR does not necessarily look good to the command processor. He suggested this:

Code:

if (test "$reply" == "y");  then
        echo -e "\nRestoring."
        STR="/bin/gunzip <  /home/mike/backups/$1 |  /usr/bin/mysql -umike_forum -psKeYzY4g $2"
        echo -e "$STR" > temp.sh
        chmod 777 temp.sh
        bash temp.sh
else
        exit
fi

and it works! Hooray!

Thanks to all of you for taking an interest.

cnmoore · 03-31-2011, 01:27 PM

I got to thinking more about this. My original script didn't work, but this does work:

Code:

STR="/bin/gunzip <  /home/mike/backups/$1 |  /usr/bin/mysql -uUser -pxxxx
eval $STR

Output with -x:
+ STR='/bin/gunzip < /home/mike/backups/mike_forum_110322-0100.sql.gz | /usr/bin/mysql uUser -pxxxx test'
+ eval /bin/gunzip '<' /home/mike/backups/mike_forum_110322-0100.sql.gz '|' /usr/bin/mysql uUser -pxxxx test
++ /bin/gunzip
++ /usr/bin/mysql uUser -pxxxx test

The 'eval' suggestion from Nominal Animal was right on, but when I tried it out it got tangled with a 'zcat' (which didn't work).

Thanks and apologies, Normal Animal.

cnmoore · 03-31-2011, 03:26 PM

Quote:

Originally Posted by Nominal Animal

You have a redirection and a pipe there,
so you actually need to do

Code:

eval "$STR"

Being new to scripting I was curious why this is. So I did some googling and found this nice clear explanation that variable expansion occurs after output redirecton:
http://linuxdevcenter.com/pub/a/linux/lpt/08_10.html

Quote:

Do you see what's happening? We're constructing a command that will look something like:

grep $grepopts $searchstring $file | sort $sortopts > $ofile
But the entire command is "hidden" in shell variables, including the I/O redirectors and various options. If the eval isn't there, this command will blow up in all sorts of bizarre ways. You'll see messages like | not found, because variable expansion occurs after output redirection. The "nested" variables (like $ofile, which is used inside of $output) won't be expanded either, so you'll also see $ofile not found. Putting an eval in front of the command forces the shell to process the line again, guaranteeing that the variables will be expanded properly and that I/O redirection will take place.

szboardstretcher · 03-31-2011, 03:27 PM

You are also doing in 3 lines, what can be done in 1.

cnmoore · 03-31-2011, 03:29 PM

Quote:

Originally Posted by szboardstretcher

You are also doing in 3 lines, what can be done in 1.

Please explain and suggest?

szboardstretcher · 03-31-2011, 03:33 PM

As i said before, when I re-wrote the part that was breaking...

Code:

STR="/bin/zcat '/home/mike/backups/$1' | /usr/bin/mysql -u username -p password '$2'"
echo -e "$STR"
eval "$STR"

can be done with:

Code:

/bin/zcat $1 | /usr/bin/mysql -u MyUser -pppppp $2

But thats your call. I just prefer to have less script to look at. Less is more.

Good luck and Regards.

cnmoore · 03-31-2011, 03:55 PM

Quote:

Originally Posted by szboardstretcher

As i said before, when I re-wrote the part that was breaking...

Code:

STR="/bin/zcat '/home/mike/backups/$1' | /usr/bin/mysql -u username -p password '$2'"
echo -e "$STR"
eval "$STR"

can be done with:

Code:

/bin/zcat $1 | /usr/bin/mysql -u MyUser -pppppp $2

But thats your call. I just prefer to have less script to look at. Less is more.

Good luck and Regards.

You're absolutely right. That does work and is certainly more compact and also more transparent - which I certainly think is a good thing in a script. I didn't know about zcat before - pipe built in is cool.

I got incompatible suggestion mixed up together and didn't absorb your very helpful http://www.linuxquestions.org/questi...4/#post4308837

Thanks!