ssh help with scripting a remote command using redirect
 

Hoping someone can help me find a way around this.

I have a script that does a mysql dump, transfers it to a standby system then I want to import that into the remote mysql.

It's restricted to run one command that parses input for bad stuff then when satisfied it's only running mysql, runs the command which is passed as a variable.

my problem is, ssh fails to parse a redirect. eg:

ssh user@remotehost "mysql -v -pmy_password < file_I_just_scped"

I get a syntax error from mysql. I can't run bash (to parse the < correctly) because bash won't run the binary.

Anyone know of a clever way around this, besides using a script on the remote system?

Hi,

you shouldn't need to scp a sript or even the file, instead pipe it into ssh. Eg
Evo2.

Hi,

hmm, just realized that you don't even need the temp file. How about:
Evo2.

Hmm I still get a syntax error from mysql. Do I need a "<" at the end of it or should it just take the dump from the pipe?

I was able to get mysql to interpret the redirection by invoking it with sudo. I like your suggestion better though, if I can get it to work.


mysqldump -ppassw --add-drop-table --all-databases | ssh user@remotehst /usr/bin/mysql -v -ppassw

yields a syntax error from the remote mysql.

Thank you for the assistance.

I don't think it was playing nice with the pipe, for some reason unknown to me. I got it to work by running this on the remote/destination host:

mysql -v -ppassw < <(ssh user@source-host "mysqldump -ppassw --all-databases")

can anyone tell me why that works fine from the command line, but if I put it into a script I get this syntax error?:

sync_mysql.sh: line 122: syntax error near unexpected token `<'
sync_mysql.sh: line 122: `/usr/bin/mysql -v -ppass < <(ssh user@source-host "mysqldump -ppassw --add-drop-table --all-databases")'

You should put #!/bin/bash at the top of your script. The <() construct is bash specific.

yes, it's in there. That was just a snippit of a larger file

Oh, it seems like the script is being run with /bin/sh instead of /bin/bash, if you do have #!/bin/bash, maybe you are actually running the script by sh myscript.sh? Otherwise, I don't know...