FreeSWITCH 1.8

variables' substrings

You can select a portion of a variable's value, (just like a substr function in many programming languages) by wrapping the variable in ${var:offset:length} tags. The arguments are:

• var: A string variable. It can be a literal string or a variable such as ${caller_id}.
• offset: The location to start copying data. The value 0 indicates the first character.
• length: How many characters to select. It is optional and if omitted, the remainder of the string is copied.

Some examples of the arguments are as follows:

set data="varname=1234567890" 
${varname:offset:length}  
${varname:0:1}  // 1 
${varname:1}    // 234567890 
${varname:-4}   // 7890 
${varname:-4:2} // 78 
${varname:4:2}  // 56 

An extension showing a variable and its substring: ...