UNIX for Dummies Questions & Answers

For anyone have work in bash shell scripting before know the if and then statement
it work like this
if (condition); then

I have create a mini shell in C, and I want to make it a bit more tolerable than the normal bash shell where you do not need the ';' between if and then if they are in the same line so it will work like this
if(condition) then
And when the user write shell script x = 7 it will be the same with x=7. I have worked with shell scripting before and it drove me crazy where i miss a space.
Does anyone at least have the bash script so i can look at for some reference because i am kind of stuck.

There are reasons why a shell syntax works in an specific way, in this case
to force the use of ; (semi-colon) between two directives in the same line.

It is possible to change a language syntax rules, but you will always have
to pass your source code through your pre-processor before the script runs.

What if other people tried to maintain your code?
Will they keep it in your off syntax way?

After you get used to writing it in your way, what will happen if you go work
to another company that for sure will not have your pre-processor?

My experience, is that it is always best to learn the rules as they are.

Not try to change what has been already established by a group of high level thinkers.

Eventually, it will come to be very easy to you and you will make less and
less syntax mistakes.

Look at this line. What do you think it does?

Code:

http_proxy="hostname:3128" wget http://somesite.com/

It temporarily exports the http_proxy environment variable, setting it to hostname:3128, before running wget to retrieve a webpage. wget sees this variable and uses this proxy. Nothing else in the script sees the http_proxy variable change. It's a very handy ability considering how so many programs use environment vars like these.

You can also do

Code:

http_proxy= wget http://sometime.com/

to prevent wget from seeing an http_proxy something else exported globally. A shell which allowed spaces after the = wouldn't ever be able to do this.

You might have heard of an attempt at creating a 'better shell' with a less shell-like syntax, called the C shell. It's one of the worst shells there is because of its poorly chosen syntax which was built on convenience, leaving many inconsistent parts, parsing bugs that are impossible to fix, and many basic features which the syntax didn't leave any way to add.

There really is a reason the shell does a lot of things the way it does.