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how to access globals in a function

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# 1  
Old 09-11-2007
how to access globals in a function
I know any globals can be directly modified in a function without passing/returning parameters- provided the function is written within the same file. However, when I wrote functions in a saparate file (so hopefully they can be re-used by multiple script programs), and then call them from the main, they no longer can access the globals.

e.g.
script updateGlobals:
#!/bin/sh
....
var1=100
var2=200
#end of updateGlobals

mainScript:
#!/bin/sh
#define globals
var1=1
var2=2
........
#calling the common script to update the globals
updateGlobals
echo $var1
echo $var2
# end of main script

It doesn't work (I get 1 & 2)- How can I get the variables updated through another script file?

Thanks for sharing your thoughts.
# 2  
Old 09-11-2007
Use the . operator to call the other script, that effectively works like "include".


Code:
. updateGlobals

# 3  
Old 09-11-2007
It's so nice to hear from you again...Thank you for all your helps!!:-)
# 4  
Old 09-11-2007
how to pass arguments to a script with operator "."
Hope this one is a bit more challenging than the previous one... how to pass parameters in the previously menioned script with operator "."

Assuming doStuff is a common script required 2 arguments, I tried both:

. doStuff parm1 parm2
. "doStuff parm1 parm2"

Nothing is working. What is the correct syntax?
Thanks
# 5  
Old 09-11-2007
How are you then addressing parm1 and parm2 in the called script?

Code:
. (source or dot operator)

SYNTAX
      . filename [arguments]

      source filename [arguments]Read and execute commands 
from the filename argument in the current shell context.

If filename does not contain a slash, the PATH variable is 
used to find filename. The current directory is searched if 
filename is not found in $PATH.

If any arguments are supplied, they become the positional
parameters when filename is executed. Otherwise the 
positional parameters are unchanged.

The return status is the exit status of the last command 
executed, or zero if no commands are executed. If filename 
is not found, or cannot be read, the return status is non-zero.

A period `.’ is a synonym for `source’

source is a bourne shell builtin and a POSIX `special’ builtin

Executing a script

[raja@AGRAJA~]$ source script_name
[raja@AGRAJA~]$ sh script_name
[raja@AGRAJA~]$ csh script_name
[raja@AGRAJA~]$ ./script_name
[raja@AGRAJA~]$ bash script_name

# 6  
Old 09-11-2007
Thanks for your prompt reply!!

I don't quite understand what "positional parameters" mean.

To be clear, DoStuff - a common wrapper script that can call a set of different scripts & do common error handing, etc- looks like this:

#!/bin/sh
if [ $# -lt 2 ]; then
echo "Usuage: DoStuff parm1 parm2. Missing parameters. Exiting..."
exit 1
else
$1 $2 # calling script $1 with parameter $2
..... # error handling etc
fi

MainScript:
...
. doStuff parm1 parm2 # how exactly the parameters should be passed here ??


If I wrote doStuff as a function within the MainScript then this would work:
doStuff parm1 parm2

However, I want doStuff to be in a saparate script so it can be shared by different script files- instead of being written in each of the files.

Many thanks!!
Last edited by bluemoon1; 09-11-2007 at 09:45 PM..
# 7  
Old 09-11-2007
Quote:
Originally Posted by bluemoon1
I don't quite understand what "positional parameters" mean.
$1 $2 $3 $4 ...
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