Asterisk func filter

Synopsis:

Filter the string to include only the allowed characters

Description:

FILTER(<allowed-chars>,<string>) – Asterisk 1.6 and later
FILTER(<allowed-chars>|<string>) – Asterisk 1.4

 

Notes

• *CLI> show function FILTER

 

Return value

Returns the resulting string.

Examples

exten => s,1,Set(foo=${FILTER(0-9,${cdrnum})}) – Asterisk 1.6 and later
exten => s,1,Set(foo=${FILTER(0123456789|${cdrnum})}) – Asterisk 1.4

Note: ISDN (Q.931) only permits ASCII characters (more precisely: the IA5 character set) as CallerID name.

Starting with Asterisk 1.6.0, FILTER permits the use of a range, as well as hexadecimal (specified as \xNN), octal (specified as \0NNN), and the usual control characters (\t, \r, and \n). A literal dash may be used either by prefixing it with a backslash or by encoding it in hexadecimal (\x2d) or octal (\055). A literal comma can likewise be encoded as \x2C or \054.

See also

• Asterisk variables
• Asterisk functions

---

• Asterisk – documentation of application commands