Shell Programming and Scripting

Hi ,

i have few doubts about the braces and spaces which are quite often used:

for instance:

when i try the belo command it will not work

Code:

export variable=  cat filename

rather when i try the cat command without any space it works fine

export variable=cat filename

Code:

and what is the significance of the {} braces???

for instance:

Code:

find . -name "*" {} -print 
what is the need of double braces like in if condition [[ ]]???

Code:

and also, could you please let me know some good references for scripting so that i could refer that in future?

Thanks in advance.

Cheers,
Waseem

Here is good tutorial which can answer most of your queries:
http://www.awprofessional.com/articl...&seqNum=3&rl=1

About Shell quotes, check here:
http://www.grymoire.com/Unix/Quote.html

About Shell Tutorial, check Tutorials section at FAQs.

Regards,
Tayyab

Hey tayyab,

thanks for your reply. Howerver, I was looking for something else, like why doesnt unix ignore the space that i gave before the cat command? and also, what is the difference between () braces and {} braces used in variables? and when do we use [] braces and () braces in conditions? and why do we use [[ ]] braces in conditions? and why do we use empty {} braces in commands??????


and also, finally, i was looking for some good e-learning material like some pdf's or online reference or anything of that sort, since, i aint got enough money to buy books

Cheers.
Waseem

Simply becasue it is a language and you have to follow the "grammar", if you don't it doesn't understand you.

The {} braces are part of the syntax of the find command.