UNIX for Dummies Questions & Answers

in ksh or bash

Code:

if (( 4 + 4 == 8 )) ; then
   test1
else
   test2
fi

or in sh

Code:

#! /usr/bin/sh

if [ `expr 4 + 4` -eq 8 ] ; then
    test1
else
    test2
fi

But I agree with porter, it is better to think in terms of variables.

Ok now I guess its time to get more detailed into what I need.

I have a process that needs to load a tbl. During the process I update an audit table with a start date when i start and an end date when I finish. Because this is a database and because I am loading stage tables I need to make sure that I have the load done before I move on to the next set of data.

The logic in english is as follows:

If the audit table has a start date and a stop date populated then go to the next step.

So in Unix What I want to do is something like
start_date = db2 "select start_date from tbl where audit_job_name = "load" and audit_start_date = "predetermained in the first part of script"
end_date= "similar logic as above"

If start_date is not null and end_date is not null call :Next_Load_Function
else if start_date is null or end_date is null call:Failure_Function
end

I dont know if I am making myself clear. I am a DBA...not a script writer. All I know is the more comlicated the code the harder it is for me to understand
Let me know if i can clear up the muddy water...

I think this is what I need. Ill play with this for a few days and see what I come up with Thanks for the Help guys!

Here is a question: Can I create a function outside of a script...like create a function .sh file and then call the function from another script?

For example I need to set certain variables in every script, can I write a functoin that does that and then just call the function in every script?

You could make use of the source functionality:

Code:

source /some/path/myfunctioncontainer.sh

or

Code:

. /some/path/myfunctioncontainer.sh

depending on what shell you're making use of.

But I cannot make a .sh file with say 5 functions and then call individual functions at seperate times....

Why not?

Code:

$ cat myfunc.sh 
#!/bin/sh

f1()
{
        echo Function 1
}

f2()
{
        echo Function 2
}

f3()
{
        echo Function 3
}

f4()
{
        echo Function 4
}

f5()
{
        echo Function 5
}

Code:

$ cat tryem.sh
#!/bin/sh

source /some/path/to/myfunc.sh

f1

touch delfile.trash

f3

foo=$(ls)

f4

f2

echo $foo

f5

rm delfile.junk

Code:

$ ./tryem.sh 
Function 1
Function 3
Function 4
Function 2
delfile.trash myfunc.sh tryem.sh
Function 5
rm: cannot remove `delfile.junk': No such file or directory