textops Module

Andrei Pelinescu-Onciul

   FhG FOKUS
   <pelinescu-onciul@fokus.fraunhofer.de>

Edited by

Andrei Pelinescu-Onciul

   <pelinescu-onciul@fokus.fraunhofer.de>

Edited by

Daniel-Constantin Mierla

   <miconda@gmail.com>

   Copyright © 2003 FhG FOKUS
   Revision History
   Revision $Revision: 6144 $ $Date: 2009-07-21 10:45:05 +0300
                              (Tue, 21 Jul 2009) $
     __________________________________________________________

   Table of Contents

   1. Admin Guide

        1.1. Overview

              1.1.1. Known Limitations

        1.2. Dependencies

              1.2.1. OpenSIPS Modules
              1.2.2. External Libraries or Applications

        1.3. Exported Functions

              1.3.1. search(re)
              1.3.2. search_body(re)
              1.3.3. search_append(re, txt)
              1.3.4. search_append_body(re, txt)
              1.3.5. replace(re, txt)
              1.3.6. replace_body(re, txt)
              1.3.7. replace_all(re, txt)
              1.3.8. replace_body_all(re, txt)
              1.3.9. replace_body_atonce(re, txt)
              1.3.10. subst('/re/repl/flags')
              1.3.11. subst_uri('/re/repl/flags')
              1.3.12. subst_user('/re/repl/flags')
              1.3.13. subst_body('/re/repl/flags')
              1.3.14. filter_body(content_type)
              1.3.15. append_to_reply(txt)
              1.3.16. append_hf(txt)
              1.3.17. append_hf(txt, hdr)
              1.3.18. insert_hf(txt)
              1.3.19. insert_hf(txt, hdr)
              1.3.20. append_urihf(prefix, suffix)
              1.3.21. is_present_hf(hf_name)
              1.3.22. append_time()
              1.3.23. is_method(name)
              1.3.24. remove_hf(hname)
              1.3.25. has_body(), has_body(mime)
              1.3.26. is_privacy(privacy_type)
              1.3.27. strip_body()
              1.3.28. add_body(body_text, new_content_type)
              1.3.29. codec_exists (name [,clock] )
              1.3.30. codec_delete (name [,clock] )
              1.3.31. codec_move_up (name [,clock] )
              1.3.32. codec_move_down (name [,clock] )
              1.3.33. codec_exists_re ( regexp )
              1.3.34. codec_delete_re ( regexp )
              1.3.35. codec_move_up_re ( regexp )
              1.3.36. codec_move_down_re ( regexp )

        1.4. Known Limitations

   List of Examples

   1.1. search usage
   1.2. search_body usage
   1.3. search_append usage
   1.4. search_append_body usage
   1.5. replace usage
   1.6. replace_body usage
   1.7. replace_all usage
   1.8. replace_body_all usage
   1.9. replace_body_atonce usage
   1.10. subst usage
   1.11. subst_uri usage
   1.12. subst usage
   1.13. subst_body usage
   1.14. filter_body usage
   1.15. append_to_reply usage
   1.16. append_hf usage
   1.17. append_hf usage
   1.18. insert_hf usage
   1.19. insert_hf usage
   1.20. append_urihf usage
   1.21. is_present_hf usage
   1.22. append_time usage
   1.23. is_method usage
   1.24. remove_hf usage
   1.25. has_body usage
   1.26. is_privacy usage
   1.27. is_privacy usage
   1.28. add_body usage
   1.29. codec_exists usage
   1.30. codec_delete usage
   1.31. codec_move_up usage
   1.32. codec_move_down usage
   1.33. codec_move_down usage
   1.34. codec_exists_re usage
   1.35. codec_delete_re usage
   1.36. codec_move_up_re usage
   1.37. codec_move_down_re usage
   1.38. codec_move_down usage

Chapter 1. Admin Guide

1.1. Overview

   The module implements text based operations over the SIP
   message processed by OpenSIPS. SIP is a text based protocol and
   the module provides a large set of very useful functions to
   manipulate the message at text level, e.g., regular expression
   search and replace, Perl-like substitutions, checks for method
   type, header presence, insert of new header and date, etc.

1.1.1. Known Limitations

   search ignores folded lines. For example,
   search("(From|f):.*@foo.bar") doesn't match the following From
   header field:
From: medabeda
 <sip:medameda@foo.bar>;tag=1234

1.2. Dependencies

1.2.1. OpenSIPS Modules

   The following modules must be loaded before this module:
     * No dependencies on other OpenSIPS modules.

1.2.2. External Libraries or Applications

   The following libraries or applications must be installed
   before running OpenSIPS with this module loaded:
     * None.

1.3. Exported Functions

1.3.1.  search(re)

   Searches for the re in the message.

   Meaning of the parameters is as follows:
     * re - Regular expression.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.1. search usage
...
if ( search("[Ss][Ii][Pp]") ) { /*....*/ };
...

1.3.2.  search_body(re)

   Searches for the re in the body of the message.

   Meaning of the parameters is as follows:
     * re - Regular expression.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.2. search_body usage
...
if ( search_body("[Ss][Ii][Pp]") ) { /*....*/ };
...

1.3.3.  search_append(re, txt)

   Searches for the first match of re and appends txt after it.

   Meaning of the parameters is as follows:
     * re - Regular expression.
     * txt - String to be appended.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.3. search_append usage
...
search_append("[Oo]pen[Ss]er", " SIP Proxy");
...

1.3.4.  search_append_body(re, txt)

   Searches for the first match of re in the body of the message
   and appends txt after it.

   Meaning of the parameters is as follows:
     * re - Regular expression.
     * txt - String to be appended.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.4. search_append_body usage
...
search_append_body("[Oo]pen[Ss]er", " SIP Proxy");
...

1.3.5.  replace(re, txt)

   Replaces the first occurrence of re with txt.

   Meaning of the parameters is as follows:
     * re - Regular expression.
     * txt - String.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.5. replace usage
...
replace("opensips", "Open SIP Server");
...

1.3.6.  replace_body(re, txt)

   Replaces the first occurrence of re in the body of the message
   with txt.

   Meaning of the parameters is as follows:
     * re - Regular expression.
     * txt - String.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.6. replace_body usage
...
replace_body("opensips", "Open SIP Server");
...

1.3.7.  replace_all(re, txt)

   Replaces all occurrence of re with txt.

   Meaning of the parameters is as follows:
     * re - Regular expression.
     * txt - String.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.7. replace_all usage
...
replace_all("opensips", "Open SIP Server");
...

1.3.8.  replace_body_all(re, txt)

   Replaces all occurrence of re in the body of the message with
   txt. Matching is done on a per-line basis.

   Meaning of the parameters is as follows:
     * re - Regular expression.
     * txt - String.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.8. replace_body_all usage
...
replace_body_all("opensips", "Open SIP Server");
...

1.3.9.  replace_body_atonce(re, txt)

   Replaces all occurrence of re in the body of the message with
   txt. Matching is done over the whole body.

   Meaning of the parameters is as follows:
     * re - Regular expression.
     * txt - String.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.9. replace_body_atonce usage
...
# strip the whole body from the message:
if(has_body() && replace_body_atonce("^.+$", ""))
        remove_hf("Content-Type");
...

1.3.10.  subst('/re/repl/flags')

   Replaces re with repl (sed or perl like).

   Meaning of the parameters is as follows:
     * '/re/repl/flags' - sed like regular expression. flags can
       be a combination of i (case insensitive), g (global) or s
       (match newline don't treat it as end of line).
       're' - is regular expresion
       'repl' - is replacement string - may contain
       pseudo-varibales
       'flags' - substitution flags (i - ignore case, g - global)

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.10. subst usage
...
# replace the uri in to: with the message uri (just an example)
if ( subst('/^To:(.*)sip:[^@]*@[a-zA-Z0-9.]+(.*)$/t:\1\u\2/ig') ) {};

# replace the uri in to: with the value of avp sip_address (just an exam
ple)
if ( subst('/^To:(.*)sip:[^@]*@[a-zA-Z0-9.]+(.*)$/t:\1$avp(sip_address)\
2/ig') ) {};

...

1.3.11.  subst_uri('/re/repl/flags')

   Runs the re substitution on the message uri (like subst but
   works only on the uri)

   Meaning of the parameters is as follows:
     * '/re/repl/flags' - sed like regular expression. flags can
       be a combination of i (case insensitive), g (global) or s
       (match newline don't treat it as end of line).
       're' - is regular expresion
       'repl' - is replacement string - may contain
       pseudo-varibales
       'flags' - substitution flags (i - ignore case, g - global)

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.11. subst_uri usage
...
# adds 3463 prefix to numeric uris, and save the original uri (\0 match)
# as a parameter: orig_uri (just an example)
if (subst_uri('/^sip:([0-9]+)@(.*)$/sip:3463\1@\2;orig_uri=\0/i')){$

# adds the avp 'uri_prefix' as prefix to numeric uris, and save the orig
inal
# uri (\0 match) as a parameter: orig_uri (just an example)
if (subst_uri('/^sip:([0-9]+)@(.*)$/sip:$avp(uri_prefix)\1@\2;orig_uri=\
0/i')){$

...

1.3.12.  subst_user('/re/repl/flags')

   Runs the re substitution on the message uri (like subst_uri but
   works only on the user portion of the uri)

   Meaning of the parameters is as follows:
     * '/re/repl/flags' - sed like regular expression. flags can
       be a combination of i (case insensitive), g (global) or s
       (match newline don't treat it as end of line).
       're' - is regular expresion
       'repl' - is replacement string - may contain
       pseudo-varibales
       'flags' - substitution flags (i - ignore case, g - global)

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.12. subst usage
...
# adds 3463 prefix to uris ending with 3642 (just an example)
if (subst_user('/3642$/36423463/')){$

...
# adds avp 'user_prefix' as prefix to username in r-uri ending with 3642
if (subst_user('/(.*)3642$/$avp(user_prefix)\13642/')){$

...

1.3.13.  subst_body('/re/repl/flags')

   Replaces re with repl (sed or perl like) in the body of the
   message.

   Meaning of the parameters is as follows:
     * '/re/repl/flags' - sed like regular expression. flags can
       be a combination of i (case insensitive), g (global) or s
       (match newline don't treat it as end of line).
       're' - is regular expresion
       'repl' - is replacement string - may contain
       pseudo-varibales
       'flags' - substitution flags (i - ignore case, g - global)

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.13. subst_body usage
...
if ( subst_body('/^o=(.*) /o=$fU ') ) {};

...

1.3.14.  filter_body(content_type)

   Filters multipart body by leaving out all other body parts
   except the first body part of given type.

   Meaning of the parameters is as follows:
     * content_type - Content type to be left in the body.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.14. filter_body usage
...
if (has_body("multipart/mixed")) {
    if (filter_body("application/sdp") {
        remove_hf("Content-Type");
        append_hf("Content-Type: application/sdp\r\n");
    } else {
        xlog("Body part application/sdp not found\n");
    }
}
...

1.3.15.  append_to_reply(txt)

   Append txt as header to the reply.

   Meaning of the parameters is as follows:
     * txt - String which may contains pseudo-variables.

   This function can be used from REQUEST_ROUTE, BRANCH_ROUTE,
   ERROR_ROUTE.

   Example 1.15. append_to_reply usage
...
append_to_reply("Foo: bar\r\n");
append_to_reply("Foo: $rm at $Ts\r\n");
...

1.3.16.  append_hf(txt)

   Appends 'txt' as header after the last header field.

   Meaning of the parameters is as follows:
     * txt - Header field to be appended. The value can contain
       pseudo-variables which will be replaced at run time.

   Note: Headers which are added in main route cannot be removed
   in further routes (e.g. failure routes). So, the idea is not to
   add there any headers that you might want to remove later. To
   add headers temporarely use the branch route because the
   changes you do there are per-branch.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.16. append_hf usage
...
append_hf("P-hint: VOICEMAIL\r\n");
append_hf("From-username: $fU\r\n");
...

1.3.17.  append_hf(txt, hdr)

   Appends 'txt' as header after first 'hdr' header field.

   Meaning of the parameters is as follows:
     * txt - Header field to be appended. The value can contain
       pseudo-variables which will be replaced at run time.
     * hdr - Header name after which the 'txt' is appended.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.17. append_hf usage
...
append_hf("P-hint: VOICEMAIL\r\n", "Call-ID");
append_hf("From-username: $fU\r\n", "Call-ID");
...

1.3.18.  insert_hf(txt)

   Inserts 'txt' as header before the first header field.

   Meaning of the parameters is as follows:
     * txt - Header field to be inserted. The value can contain
       pseudo-variables which will be replaced at run time.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.18. insert_hf usage
...
insert_hf("P-hint: VOICEMAIL\r\n");
insert_hf("To-username: $tU\r\n");
...

1.3.19.  insert_hf(txt, hdr)

   Inserts 'txt' as header before first 'hdr' header field.

   Meaning of the parameters is as follows:
     * txt - Header field to be inserted. The value can contain
       pseudo-variables which will be replaced at run time.
     * hdr - Header name before which the 'txt' is inserted.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.19. insert_hf usage
...
insert_hf("P-hint: VOICEMAIL\r\n", "Call-ID");
insert_hf("To-username: $tU\r\n", "Call-ID");
...

1.3.20.  append_urihf(prefix, suffix)

   Append header field name with original Request-URI in middle.

   Meaning of the parameters is as follows:
     * prefix - string (usually at least header field name).
     * suffix - string (usually at least line terminator).

   This function can be used from REQUEST_ROUTE, FAILURE_ROUTE,
   BRANCH_ROUTE.

   Example 1.20. append_urihf usage
...
append_urihf("CC-Diversion: ", "\r\n");
...

1.3.21.  is_present_hf(hf_name)

   Return true if a header field is present in message.

Note

   The function is also able to distinguish the compact names. For
   exmaple "From" will match with "f"

   Meaning of the parameters is as follows:
     * hf_name - Header field name.(long or compact form)

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE.

   Example 1.21. is_present_hf usage
...
if (is_present_hf("From")) log(1, "From HF Present");
...

1.3.22.  append_time()

   Adds a time header to the reply of the request. You must use it
   before functions that are likely to send a reply, e.g., save()
   from 'registrar' module. Header format is: "Date: %a, %d %b %Y
   %H:%M:%S GMT", with the legend:
     * %a abbreviated week of day name (locale)
     * %d day of month as decimal number
     * %b abbreviated month name (locale)
     * %Y year with century
     * %H hour
     * %M minutes
     * %S seconds

   Return true if a header was succesfully appended.

   This function can be used from REQUEST_ROUTE, FAILURE_ROUTE,
   BRANCH_ROUTE.

   Example 1.22. append_time usage
...
append_time();
...

1.3.23.  is_method(name)

   Check if the method of the message matches the name. If name is
   a known method (invite, cancel, ack, bye, options, info,
   update, register, message, subscribe, notify, refer, prack),
   the function performs method ID testing (integer comparison)
   instead of ignore case string comparison.

   The 'name' can be a list of methods in the form of
   'method1|method2|...'. In this case, the function returns true
   if the SIP message's method is one from the list. IMPORTANT
   NOTE: in the list must be only methods defined in OpenSIPS with
   ID (invite, cancel, ack, bye, options, info, update, register,
   message, subscribe, notify, refer, prack, publish; for more
   see: http://www.iana.org/assignments/sip-parameters).

   If used for replies, the function tests the value of method
   field from CSeq header.

   Meaning of the parameters is as follows:
     * name - SIP method name

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, and BRANCH_ROUTE.

   Example 1.23. is_method usage
...
if(is_method("INVITE"))
{
    # process INVITEs here
}
if(is_method("OPTION|UPDATE"))
{
    # process OPTIONs and UPDATEs here
}
...

1.3.24.  remove_hf(hname)

   Remove from message all headers with name "hname"

   Returns true if at least one header is found and removed.

   Meaning of the parameters is as follows:
     * hname - header name to be removed.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE and BRANCH_ROUTE.

   Example 1.24. remove_hf usage
...
if(remove_hf("User-Agent"))
{
    # User Agent header removed
}
...

1.3.25.  has_body(), has_body(mime)

   The function returns true if the SIP message has a body
   attached. The checked includes also the "Content-Lenght" header
   presence and value.

   If a paramter is given, the mime described will be also checked
   against the "Content-Type" header.

   Meaning of the parameters is as follows:
     * mime - mime to be checked against the "Content-Type"
       header. If not present or 0, this check will be disabled.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE and BRANCH_ROUTE.

   Example 1.25. has_body usage
...
if(has_body("application/sdp"))
{
    # do interesting stuff here
}
...

1.3.26.  is_privacy(privacy_type)

   The function returns true if the SIP message has a Privacy
   header field that includes the given privacy_type among its
   privacy values. See
   http://www.iana.org/assignments/sip-priv-values for possible
   privacy type values.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE and BRANCH_ROUTE.

   Example 1.26. is_privacy usage
...
if(is_privacy("id"))
{
    # do interesting stuff here
}
...

1.3.27.  strip_body()

   If the message has a body, this function deletes it, correcting
   Content-Length. This function also deletes the Content-Type
   header.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.27. is_privacy usage
...
strip_body();
...

1.3.28.  add_body(body_text, new_content_type)

   This function can be used to add a body to a message. If a body
   already exists, it will be replaced with the new one. The
   second parameter is the content type of the new body. It is
   optional: in case the function is used to replace an existing
   body with a body of the same type, there is no need to set this
   parameter. If the message has no body or if the types are
   different, it is compulsory to set this parameter.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.28. add_body usage
...
add_body("Hello World!", "text/plain");
...

1.3.29.  codec_exists (name [,clock] )

   This function can be used to verify if a codec exists inside an
   sdp payload. It will search for the codec inside all streams
   from all sdp sessions. If it is found anywhere it will return
   TRUE otherwise it will return FALSE. The second parameter is
   optional, if it is not supplied any clockrate will match.
   Parameters are CASE INSENSITIVE.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.29. codec_exists usage
...
codec_exists("speex");
or
codec_exists("GSM","8000");
...

1.3.30.  codec_delete (name [,clock] )

   This function can be used to delete a codec from inside an sdp
   payload. It will search for the codec inside all streams from
   all sdp sessions. If it is found anywhere it will be deleted
   from the mapping ("a=...") and from the list of indexes
   ("m=..."). Returns TRUE if any deletion occured otherwise it
   will return FALSE. The second parameter is optional, if it is
   not supplied any clockrate will match and all will be deleted.
   Parameters are CASE INSENSITIVE.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.30. codec_delete usage
...
codec_delete("speex");
or
codec_delete("GSM","8000");
...

1.3.31.  codec_move_up (name [,clock] )

   This function can be used to move a codec up in the list of
   indexes ("m=..."). It will search for the codec inside all
   streams from all sdp sessions. If it is found anywhere it will
   be moved to the top of the index list. Returns TRUE if any
   moves occured otherwise it will return FALSE. The second
   parameter is optional, if it is not supplied any clockrate will
   match and all codecs will be moved to the front while
   preserving their original ordering. Parameters are CASE
   INSENSITIVE.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.31. codec_move_up usage
...
codec_move_up("speex");
or
codec_move_up("GSM","8000");
...

1.3.32.  codec_move_down (name [,clock] )

   This function can be used to move a codec down in the list of
   indexes ("m=..."). It will search for the codec inside all
   streams from all sdp sessions. If it is found anywhere it will
   be moved to the back of the index list. Returns TRUE if any
   moves occured otherwise it will return FALSE. The second
   parameter is optional, if it is not supplied any clockrate will
   match and all codecs will be moved to the back while preserving
   their original ordering. Parameters are CASE INSENSITIVE.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.32. codec_move_down usage
...
codec_move_down("speex");
or
codec_move_down("GSM","8000");
...

   Example 1.33. codec_move_down usage
...
/*
  This example will move speex with 8000 codec to the back of the list,
  then it will erase GSM with 8000 clock, and then it will bring all
  speex codecs to the front of the list. Speex/8000 will be behind any
  other speex.
*/
codec_move_down("speex","8000");
codec_delete("GSM","8000");
codec_move_up("speex");
...

1.3.33.  codec_exists_re ( regexp )

   This function has the same effect as codec_exists ( without the
   clock parameter ) the only difference is that it takes a POSIX
   regular expression as a parameter.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.34. codec_exists_re usage
...
codec_exists_re("sp[a-z]*");
...

1.3.34.  codec_delete_re ( regexp )

   This function has the same effect as codec_delete ( without the
   clock parameter ) the only difference is that it takes a POSIX
   regular expression as a parameter.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.35. codec_delete_re usage
...
codec_delete_re("PCMA|PCMU");
...


1.3.35.  codec_move_up_re ( regexp )

   This function has the same effect as codec_move_up ( without
   the clock parameter ) the only difference is that it takes a
   POSIX regular expression as a parameter.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.36. codec_move_up_re usage
...
codec_move_up_re("sp[a-z]*");
...

1.3.36.  codec_move_down_re ( regexp )

   This function has the same effect as codec_move_down ( without
   the clock parameter ) the only difference is that it takes a
   POSIX regular expression as a parameter.

   This function can be used from REQUEST_ROUTE, ONREPLY_ROUTE,
   FAILURE_ROUTE, BRANCH_ROUTE and LOCAL_ROUTE.

   Example 1.37. codec_move_down_re usage
...
codec_move_down_re("sp[a-z]*");
...

   Example 1.38. codec_move_down usage
...
/*
  This example will move speex with 8000 codec to the back of the list,
  then it will erase GSM with 8000 clock, and then it will bring all
  speex codecs to the front of the list. Speex/8000 will be behind any
  other speex.
*/
codec_move_down("speex","8000");
codec_delete("GSM","8000");
codec_move_up("speex");
...

1.4. Known Limitations

   Search functions are applied to the current message so
   modifications made to the sdp will be visible to the
   codec_exists functions( e.g. after calling
   codec_delete("speex") , codec_exists("speex") will return false
   ).
