topic Re: How to extract char from string in $variable? in Operating System - Linux

How to extract char from string in $variable?

Andrew Yip — Tue, 02 May 2006 01:34:29 GMT

Hi,

How do i extract certain characters from a string stored in a $variable?

For example:

set text = "01L"

i want to extract and store "01" only into another $variable. Thanks!

Re: How to extract char from string in $variable?

Rajeev Shukla — Tue, 02 May 2006 01:44:36 GMT

try
echo $text|cut -c 1,2
or
echo $text|cut -c 1-2 (to any digits you want to cut)

Re: How to extract char from string in $variable?

Rajeev Shukla — Tue, 02 May 2006 01:47:17 GMT

say your assign the value to $valiable as
export variable="01L"
var1=`echo $variable|cut -c 1,2`
echo $var1

Re: How to extract char from string in $variable?

Andrew Yip — Tue, 02 May 2006 01:58:37 GMT

Thanks Raj!
I've got it!

Re: How to extract char from string in $variable?

Steven E. Protter — Tue, 02 May 2006 02:14:11 GMT

Shalom,

http://www.google.com/url?sa=t&ct=res&cd=2&url=http%3A%2F%2Fwww.dreamsyssoft.com%2Funix-shell-scripting%2Fadvanced-tutorial.php&ei=ef5WRJHWI7_SwgHy1OT5Bw&sig2=IZ1E-i7ZUt4wAbup0PpOR

http://www.google.com/url?sa=t&ct=res&cd=1&url=http%3A%2F%2Fwww.cactus.org%2F~dak%2Fshellscript.html&ei=ef5WRJHWI7_SwgHy1OT5Bw&sig2=KsUK1AlA6rlf7qHRH5ZgvQ

Perhaps these links will help.

SEP

Re: How to extract char from string in $variable?

Hein van den Heuvel — Tue, 02 May 2006 06:41:55 GMT

Andrew,

I'm glad you found a solution.
However, it involves a fork of a utility where it seems that a native shell command can do the trick.
For onesies-twosies it does not matter, for commands executed in a tight loop it can make a critical difference in execution performance.

The shell has several editing operations.
In your case i woudl consider 'tail end pattern deletion'

For example:

# text="01L"
# other=${text%[A-Z]}
# echo $other
01

from "man ksh"
:
${parameter%pattern}
:
If the shell pattern matches the end of the value of parameter, the value of parameter with the matched part is deleted; otherwise substitute the value of parameter. In the former, the smallest matching pattern is deleted; in the latter, the largest matching pattern is deleted.

hth,
Hein.