Substring of string in tag + shell script

linux_man · 02-04-2010, 04:17 AM

Hi,

Please help me solve the following as I am new to scripting

I have a string variable

var1=<default>111</default>

I want the value between default tags 111 in this case.

I treid to use ${var1:10:3}
But the execution gived "bad substitution' error.

If the tags are removed and substring is fetched it works fine.
Please help me.
Is there any other was to get substring in a string with tags.
Thanks i advance

AngTheo789 · 02-04-2010, 04:42 AM

Indexing is zerobased, so it should be ${var:9:3}. Otherwise it works on my bash shell.

catkin · 02-04-2010, 04:54 AM

You need quotes to assign the string:

Code:

c:~$ var1=<default>111</default>
bash: syntax error near unexpected token `111'

Now with quotes and showing a way to parse the value from between the tags

Code:

c:~$ var1='<default>111</default>'
c:~$ var1="${var1#<default>}"
c:~$ var1="${var1%</default>}"
c:~$ echo $var1
111

AngTheo789 · 02-04-2010, 05:58 AM

Quotes are needed indeed!

linux_man · 02-04-2010, 09:04 PM

Thanks for ur reply...

Can you please tell me a way to extract 111 from <default>111</default> using SED command.
I do not want to hard code the character position to get the value.

catkin · 02-04-2010, 10:32 PM

Quote:

Originally Posted by linux_man

I do not want to hard code the character position to get the value.

The technique shown above using bash parameter expansion does not hard code the character position and runs faster than using sed.