parsing strings

[prad87]

what is the best command to use to parse strings?
I have a variable $str and need to parse this string.
Can you provide an example of the command used to get a substring of $str based on the index values of start and end

[Cabhan]

This is a feature built into Bash. See this page:
Manipulating Strings

Go to the section called "Substring Extraction".

[prad87]

is there any other command. that I could use?...the expr is giving me lot of syntax issues....i just copied n pasted many different examples and most of them gave me a syntax error

[Cabhan]

For a positional substring, you shouldn't need expr at all...

bricka@eagle ~ $ string="foobar"; echo ${string:3}; echo ${string:2:2}
bar
ob

You can use the ${STRING:START:LENGTH} syntax to accomplish this.