What is a command wrapper?

johnsanty · 09-21-2006, 10:27 PM

Hi All,

I came across with the term "command wrapper". What does it really mean? I've been searching the web but I still don't have a clear picture of what this term really is. Could somebody clarify me on this one...Thanks for you prompt reply..

John.

zhangmaike · 09-22-2006, 12:40 AM

In general, a wrapper extends or makes it easier to use the command that it is "wrapping" without reimplementing that command's functionality - it simply calls the original command. These are usually scripts.

primo · 09-22-2006, 01:35 AM

In the context of system's programming, a command wrapper may be a program that makes available a particular call to the user. Examples may be readlink(1), realpath(1), truncate(1), etc.

johnsanty · 09-22-2006, 06:39 AM

Quote:

Originally Posted by zhangmaike

In general, a wrapper extends or makes it easier to use the command that it is "wrapping" without reimplementing that command's functionality - it simply calls the original command. These are usually scripts.

So basically, it's a script which contains a specific command? So, for example if I want to wrap a command "ls", all I need to do is write a script and put the command "ls" in this script? Is that correct? If not, could you give me an example? Thanks for your prompt reply...

John

PTrenholme · 09-22-2006, 07:15 AM

A simple example is the KDE windowing environment where many commands are embeded in the system and executed as needed to display various windows on your screen.

xhi · 09-22-2006, 02:19 PM

Quote:

Originally Posted by johnsanty

So basically, it's a script which contains a specific command? So, for example if I want to wrap a command "ls", all I need to do is write a script and put the command "ls" in this script? Is that correct? If not, could you give me an example? Thanks for your prompt reply...

John

yeh pretty much. usually when you wrap something you usually do it because you want to change the behavior of the command, but still need the same base functionality. so with ls example, if you want to print out the current directoy that you are listing then it would be something like

Code:

#!/bin/bash
echo "listing contents of " `pwd`
ls

put that in an executable file named lspwd and you have just wrapped ls command

also in a more programming sense a wrapper is used to change an interface in some way.. but it sounds like you are looking for something like the above right..