Bash code design

rejeep · 08-14-2007, 01:37 PM

Hi!

I am creating a Bash script. In the script I have about 7-10 functions.

How would you make the design? I don't like that the functions have to be defined before you call it. So I want to avoid having all functions in the beginning of the code.

Is there any way you can declare them like in C and maybe even put the functions in a different file?

How would you do it? The total amount of rows will be when then script is done about 200-300.

Thanks!

rubadub · 08-14-2007, 01:38 PM

Put each function in a file of it's own...

rejeep · 08-14-2007, 01:43 PM

Quote:

Originally Posted by rubadub

Put each function in a file of it's own...

Hmm... That seems a little to much?

Can you say why I would do it like this?

And how would I make the functions visible for the main script file?

thebouv · 08-14-2007, 01:52 PM

Quote:

Originally Posted by rejeep

Hmm... That seems a little to much?

Can you say why I would do it like this?

And how would I make the functions visible for the main script file?

Putting each function in its own file is bad advice in my opinion since you're trying to design a full bash app with X functionality.

Create a source file, say called myfunctions.sh, and in your main program you mention above, simple do this first:

source myfunctions.sh

Basically that 'source' command embeds the code in myfunctions.sh into your main script first, as if you had typed them there. Therefore, your functions are defined before they are called, just as you requested.

rejeep · 08-14-2007, 02:02 PM

Quote:

Originally Posted by thebouv

Putting each function in its own file is bad advice in my opinion since you're trying to design a full bash app with X functionality.

"with X functionality". From where did you get that? =)

Quote:

Originally Posted by thebouv

Create a source file, say called myfunctions.sh, and in your main program you mention above, simple do this first:

source myfunctions.sh

Basically that 'source' command embeds the code in myfunctions.sh into your main script first, as if you had typed them there. Therefore, your functions are defined before they are called, just as you requested.

Having all functions in one file makes more sense to me.

How then would you recommend me organize my files?

I must put the main file in a folder defined in $PATH. But I guess I don't want to make the "myfunctions.sh" runnable as it gets.

How would I solve this best?

thebouv · 08-14-2007, 02:25 PM

Quote:

Originally Posted by rejeep

"with X functionality". From where did you get that? =)

My bad, I didn't really mean X functionality, as in X windows system. I mean X as in .. a variable .. as in I should have said that different. Ignore that part.

I could have just said "with blahblahblah functionality". Nevermind.

Quote:

Having all functions in one file makes more sense to me.

How then would you recommend me organize my files?

I must put the main file in a folder defined in $PATH. But I guess I don't want to make the "myfunctions.sh" runnable as it gets.

How would I solve this best?

Well your source command can be an absolute path such as:

source /path/to/myfunctions.sh

Or perhaps you want to make a folder such as /home/yourname/library and put your file in there, and whenever you want to use those functions, you can use something like:

source $HOME/library/myfunctions.sh

This way you build yourself a little library of bash source code for reuse.

Sound good?

rejeep · 08-15-2007, 04:13 AM

Quote:

Originally Posted by thebouv

My bad, I didn't really mean X functionality, as in X windows system. I mean X as in .. a variable .. as in I should have said that different. Ignore that part.

I could have just said "with blahblahblah functionality". Nevermind.

Haha

Quote:

Originally Posted by thebouv

Well your source command can be an absolute path such as:

source /path/to/myfunctions.sh

Or perhaps you want to make a folder such as /home/yourname/library and put your file in there, and whenever you want to use those functions, you can use something like:

source $HOME/library/myfunctions.sh

This way you build yourself a little library of bash source code for reuse.

Sound good?

Sounds like of course! Why didn't I think of that! =)

Thanks a lot!

bigearsbilly · 08-15-2007, 05:31 AM

you can put all the functions in a separate file, say funcs.sh
then in the script:

Code:

#!/bin/bash -u
. funcs.sh

# they are now defined

edit: oops sorry didn't read all posts properly

makyo · 08-15-2007, 09:36 AM

Hi.

There is an argument for placing the functions in separate files. The Korn shell has a feature, autoload, which allows functions to be loaded from files when they are invoked (provided they can be found in FPATH). This is also available in pdksh.

There are also demonstration functions of an autoload feature in the bash documentation files (not the man page).

I have not used either extensively, but it might be useful for situations where portability is not an important consideration ... cheers, makyo