How to concatenate output of two commands to a file

starmonche · 05-01-2009, 12:19 PM

I have a file called "query.sql" that looks like this:

SELECT
field1,field2,field3
FROM
sometable
WHERE
oldcondition

And I have a script called "maxdate.php" that returns this:

newcondition

I'm looking to replace the last line of the file "query.sql" with the output from the command "maxdate.php".

This command drops the last line of the file:
$ sed -e '$d' query.sql

And this gives me what I want to put in its place:
$ ./maxdate.php

How in the world can I combine the output of both commands and dump it into "query.sql"?

oddsocks · 05-01-2009, 12:28 PM

I might be misunderstanding what you're trying to do, or the reasons why but what about:

sed -i '$d' query.sql ; ./maxdate.php >> query.sql

MensaWater · 05-01-2009, 12:31 PM

sed -e s/oldcondition/`maxdate.php`/ query.sql

Note the symbols around maxdate.php are back ticks not single quotes. They tell the command line to execute maxdate.php and use its result (newcondition).

The sed line says substitute that result (newcondition) for oldcondition. It will output to screen. You'll have to redirect into a new file then copy the new file back over the original. (Ideally you'll also save a copy of original before doing that so you can recover if you need to do so.)

forrestt · 05-01-2009, 12:33 PM

I think you really want

Code:

(sed -e '$d' query.sql;./maxdate.php) > query.sql

HTH

Forrest