Core Variables
OpenSIPS provides multiple types of variables to be used in the routing script. The difference between the types of variables comes from:
- its context - a variable is attached to a context, like the context of a SIP message, of a SIP transaction or dialog. The variable will be visible all the time within that context (across all the script routes where the context is present)
- read-write status - some types of variables are read-only
- number of values - some variables may keep multiple values at the same time
The OpenSIPS variables can be easily identified in the script as all their names (or notations) start with the $ sign.
Syntax:
The complete syntax for a pseudo variable is:
$(<context>name(subname)[index]{transformation})
The fields written in italics are optional. The fields meaning is:
- name(mandatory) - the pseudo-variable name(type).
Ex: var, avp, ru, DLG_status, etc. - subname - the identifier of a certain pv of a given type.
Ex: hdr(From), avp(name). - index - a pv can store more than one value - it can refer to a list of values. You can access a certain value from the list if you specify its index. You can also specify indexes with negative values, -1 means the last inserted, -2 the value before the previous inserted one.
- transformation - a series of processing actions can be applied on pseudo-variable. You can find the whole list of possible transformations here. The transformations can be cascaded, using the output of one transformation as the input of another.
- context - the context in which the pseudo0variable will be evaluated. Now there are 2 pv contexts: reply and request. The reply context can be used in the failure route to request for the pseudo-variable to be evaluated in the context of the reply message. The request context can be used if in a reply route is desired for the pv to be evaluated in the context of the corresponding request.
Usage examples:
- Only name:
$ru - Name and ‘subname:
$hdr(Contact) - Name and index:
$(ct[0]) - Name, subname and index:
$(avp(caller_dids)[2]) - Context
$(<request>ru)from a reply route will get the Request-URI from the request$(<reply>hdr(Contact))context can be used from failure route to access information from the reply
Types of variables:
-
script variables - as the name says, these variables are strictly bound to the script routes.
-
AVP - Attribute Value Pair - the AVPs are dynamic variables (as name) that can be created and attached to a SIP message or transaction (if stateful processing is used). So, you may see them as transaction level variables.
-
reference variables - variables to provide access to information from the current context - the current SIP message, transaction, dialog, or from the current process (non SIP information).
-
escape sequences - escape sequences used to format the strings; they are actually not variables, but rather formatters.
Script variables
Section titled “Script variables”Naming: $var(name)
These variables are attached to the script, being persistent to the whole execution of a top route (including all its sub-routes). Once the execution of the top route ended, the script variables are lost, not to be used again. Also, be careful and initialize them when used for the first time (in a top route) as you may inherite garbage. Script variables are read write and they can have integer or string values. A script variable can only hold a single value. A new assignment (or write operation) will overwrite the existing value.
Hints:
- if you want to start using a script variable in a route, better initialize it with same value (or reset it), otherwise you may inherit a value from a previous route that was executed by the same process.
- a script variable can only hold one value.
Example of usage:
$var(a) = 2; # sets the value of variable 'a' to integer '2'$var(a) = "2"; # sets the value of variable 'a' to string '2'$var(a) = 3 + (7&(~2)); # arithmetic and bitwise operation$var(a) = "sip:" + $au + "@" + $fd; # compose a value from authentication username and From URI domain
# using a script variable for testsif( [ $var(a) & 4 ] ) { xlog("var a has third bit set\n");}AVP variables
Section titled “AVP variables”Naming: $avp(name) or $(avp(name)[N])
A message or a transaction will initially (when received or created) have an empty list of AVPS attached to it. During the routing script, the script directly or functions called from script may create new AVPS that will automatically attached to the message/transaction. The AVPS will be visible in all routes where any message (reply or request) of the transaction will be processed - branch_route , failure_route, onreply_route (for this last route you need to enable the TM parameter onreply_avp_mode).
AVPs are read write and an existing AVP can be even deleted (removed).
An AVP may contain multiple values - a new assignment (or write operation) will add a new value to the AVP; the values are kept in “last added first to be used” order (stack).
When using the index “N” you can force the AVP to return a certain value (the N-th value). If no index is given, the first value will be returned.
A special index append is defined to allow you to add a new value at the end of the list (at the bottom of the stack) - $(avp(name)[append]) = “last value”;
Hints:
- to enable AVPs in onreply_route, use “modparam(“tm”, “onreply_avp_mode”, 1)”
- if multiple values are used for a single AVP, the values are index in revert order than added
- AVPs are part of the transaction context, so they will be visible everywhere where the transaction is present.
- the value of an AVP can be deleted
Example of usage:
- Transaction persistence example
# enable avps in onreply routemodparam("tm", "onreply_avp_mode", 1)...route{...$avp(tmp) = $Ts ; # store the current time (at request processing)...t_onreply("handle_reply");t_relay();...}
onreply_route[handle_reply] { if (t_check_status("200")) { # calculate the setup time $var(setup_time) = $Ts - $avp(tmp); }}- Multiple values example
$avp(demo) = "one";# we have a single value
$avp(demo) = "two";# we have two values ("two","one")
$avp(demo) = "three";# we have three values ("three","two","one")
xlog("accessing values with no index: $avp(demo)\n");# this will print the first value, which is the last added value -> "three"
xlog("accessing values with no index: $(avp(demo)[2])\n");# this will print the index 2 value (third one), -> "one"
# remove the first value of the avp (lastly added one); if there is only one value, the AVP itself will be destroyed$avp(demo) = NULL;
# delete all values and destroy the AVPavp_delete("$avp(demo)/g");
# delete the value located at a certain index$(avp(demo)[1]) = NULL;
# overwrite the value at a certain index$(avp(demo)[0]) = "zero";The AVPOPS module provides a lot of useful functions to operate AVPs (like checking values, pushing values into different other locations, deleting AVPs, etc).
Reference Variables
Section titled “Reference Variables”Naming: $name
They provide access to information from the SIP message/transaction/dialog or OpenSIPS internals.
For example, a reference variable may allow access to the processed SIP message (headers, RURI, transport level info, and so on) or from OpenSIPS internals (time values, process PID, return code of a function). Depending of what info they provide, the PVs are either bound to the message, either to nothing (global).
Most of the reference variables are read-only and only several allow write operations. The reference variables may return several values or only one, depending of the referred info (if can have multiple values or not).
Standard reference variables are read-only and return a single value (if not otherwise documented).
Hints:
- most of reference variables are made available by OpenSIPS core, but there are also module exporting such variables (to make available info specific to that module) - check the modules documentation.
- the reference variables are also known as pseudo-variables or PV. This is an old terminology.
Predefined (provided by core) PVs are listed in alphabetical order:
URI in SIP Request’s P-Asserted-Identity header - $ai
Section titled “URI in SIP Request’s P-Asserted-Identity header - $ai”$ai - reference to URI in request’s P-Asserted-Identity header (see RFC 3325)
Authentication Digest URI - $adu
Section titled “Authentication Digest URI - $adu”$adu - URI from Authorization or Proxy-Authorization header. This URI is used when calculating the HTTP Digest Response.
Authentication realm - $ar
Section titled “Authentication realm - $ar”$ar - realm from Authorization or Proxy-Authorization header
Auth username user - $au
Section titled “Auth username user - $au”$au - user part of username from Authorization or Proxy-Authorization header
Auth username domain - $ad
Section titled “Auth username domain - $ad”$ad - domain part of username from Authorization or Proxy-Authorization header
Auth nonce - $an
Section titled “Auth nonce - $an”$an - the nonce from Authorization or Proxy-Authorization header
Auth response - $auth.resp
Section titled “Auth response - $auth.resp”$auth.resp - the authentication response from Authorization or Proxy-Authorization header
Auth nonce - $auth.nonce
Section titled “Auth nonce - $auth.nonce”$auth.nonce - the nonce string from Authorization or Proxy-Authorization header
Auth cnonce - $auth.cnonce
Section titled “Auth cnonce - $auth.cnonce”$auth.cnonce - the client nonce string from Authorization or Proxy-Authorization header
Auth opaque - $auth.opaque
Section titled “Auth opaque - $auth.opaque”$auth.opaque - the opaque string from Authorization or Proxy-Authorization header
Auth algorithm - $auth.alg
Section titled “Auth algorithm - $auth.alg”$auth.alg - the algorithm string from Authorization or Proxy-Authorization header
Auth QOP - $auth.qop
Section titled “Auth QOP - $auth.qop”$auth.qop - the value of qop parameter from Authorization or Proxy-Authorization header
Auth nonce count (nc) - $auth.nc
Section titled “Auth nonce count (nc) - $auth.nc”$auth.nc - the value of nonce count parameter from Authorization or Proxy-Authorization header
Auth whole username - $aU
Section titled “Auth whole username - $aU”$aU - whole username from Authorization or Proxy-Authorization header
Acc username - $Au
Section titled “Acc username - $Au”$Au - username for accounting purposes. It’s a selective pseudo variable (inherited from acc module). It returns $au if it exists or From username otherwise.
Argument options - $argv
Section titled “Argument options - $argv”$argv - provides access to command line arguments specified with ‘-o’ option.
Examples:
# for option '-o foo=0' xlog("foo is $argv(foo) \n");Branch flags list - $bf
Section titled “Branch flags list - $bf”$bf - displays a list with the branch flags set for the current SIP request
Branch - $branch
Section titled “Branch - $branch”$branch - this variable is used for creating new branches by writing into it the value of a SIP URI.
Examples:
# creates a new branch $branch = "sip:new@doamin.org"; # print its URI xlog("last added branch has URI $(branch(uri)[-1]) \n");Branch fields - $branch(field)
Section titled “Branch fields - $branch(field)”$branch() - this variable provides read/write access to all fields/attributes of an already existing branch (prior created with append_branch() ). The fields of the branch are:
- uri - the RURI of the branch (string value)
- duri - destination URI of the branch (outbound proxy of the branch) (string value)
- q - q value of the branch (int value)
- path - the PATH string for this branch (string value)
- flags - the branch flags of this branch (int value)
- socket - the local socket to be used for relaying this branch (string value)
The variable accepts also index
$(branch(uri)[1])for accessing a specific branch (multiple branches can be defined at a moment). The index starts from 0 (first branch). If the index is negative, it is considered the n-th branch from the end ( index -1 means the last branch).
To get all branches, use the * index - $(branch(uri)[*]).
Examples:
# creates the first branch append_branch(); # creates the second branch force_send_socket(udp:193.468.1.12:5060); $du = "sip:193.468.3.40"; append_branch("sip:foo@bar.com","0.5");
# display branches xlog("----- branch 0: $(branch(uri)[0]) , $(branch(q)[0]), $(branch(duri)[0]), $(branch(path)[0]), $(branch(flags)[0]), $(branch(socket)[0]) \n"); xlog("----- branch 1: $(branch(uri)[1]) , $(branch(q)[1]), $(branch(duri)[1]), $(branch(path)[1]), $(branch(flags)[1]), $(branch(socket)[1]) \n");
# do some changes over the branches $branch(uri) = "sip:user@domain.ro"; # set URI for the first branch $(branch(q)[0]) = 1000; # set to 1.00 for the first branch $(branch(socket)[1]) = NULL; # reset the socket of the second branch $branch(duri) = NULL; # reset the destination URI or the first branchBranch flag - $branch.flag()
Section titled “Branch flag - $branch.flag()”$(branch.flag(flag_name)[branch]) - this variable provides read/write access to the value of a single certain branch flag (identified by name). The values accepted for writing are 1 (set) and 0 (unset). The returned values are 1/”true” (set) and 0/”false” (unset). An index is accepted, in order to access the flag for a certain branch. By default the 0 (or current) branch accessed (for more on index, see the the branch.fields variable) - note that ”*” is not accepted.
setbflag("X"); xlog("---- flag value is $branch.flag(X) \n"); $branch.flag(X) = off; xlog("---- flag value is $branch.flag(X) \n");Call-Id - $ci
Section titled “Call-Id - $ci”$ci - reference to body of call-id header
Content-Length - $cl
Section titled “Content-Length - $cl”$cl - reference to body of content-length header
CSeq number - $cs
Section titled “CSeq number - $cs”$cs - reference to cseq number from cseq header
Contact instance - $ct
Section titled “Contact instance - $ct”$ct - reference to contact instance/body from the contact header. A contact instance is display_name + URI + contact_params. As a Contact header may contain multiple Contact instances and a message may contain multiple Contact headers, an index was added to the $ct variable:
$ct-first contact instance from message$(ct[n])- the n-th contact instance form the beginning of message, starting with index 0$(ct[-n])- the n-th contact instance form the end of the message, starting with index -1 (the last contact instance)
Fields of a contact instance - $ct.fields(field)
Section titled “Fields of a contact instance - $ct.fields(field)”$ct.fields() - reference to the fields of a contact instance/body (see above). Supported fields are:
- name - display name
- uri - contact uri
- q - q param (value only)
- expires - expires param (value only)
- methods - methods param (value only)
- received - received param (value only)
- params - all params (including names)
Examples:
$ct.fields(uri)- the URI of the first contact instance$(ct.fields(name)[1])- the display name of the second contact instance
Content-Type - $cT
Section titled “Content-Type - $cT”$cT - reference to body of Content-Type header and also the content-type headers inside a multi-part body
$cT- the main Content-Type of the message; the one inside the headers$(cT[n])- the n-th Content-Type inside a multi-part body from the beginning of message, starting with index 0$(cT[-n])- the n-th Content-Type inside a multi-part body from the end of the message, starting with index -1 (the last contact instance)$(cT[*])- all the Content-Type headers including the main one and the ones from the multi-part body
Domain of destination URI - $dd
Section titled “Domain of destination URI - $dd”$dd - reference to domain of destination uri
Diversion header URI - $di
Section titled “Diversion header URI - $di”$di - reference to Diversion header URI
Diversion “privacy” parameter - $dip
Section titled “Diversion “privacy” parameter - $dip”$dip - reference to Diversion header “privacy” parameter value
Diversion “reason” parameter - $dir
Section titled “Diversion “reason” parameter - $dir”$dir - reference to Diversion header “reason” parameter value
Port of destination URI - $dp
Section titled “Port of destination URI - $dp”$dp - reference to port of destination uri
Transport protocol of destination URI - $dP
Section titled “Transport protocol of destination URI - $dP”$dP - reference to transport protocol of destination uri
Destination set - $ds
Section titled “Destination set - $ds”$ds - reference to destination set
Destination URI - $du
Section titled “Destination URI - $du”$du - reference to destination uri (outbound proxy to be used for sending the request)
If loose_route() returns TRUE a destination uri is set according to the first Route header.
Alias: $duri
Error class - $err.class
Section titled “Error class - $err.class”$err.class - the class of error (now is ‘1’ for parsing errors)
Error level - $err.level
Section titled “Error level - $err.level”$err.level - severity level for the error
Error info - $err.info
Section titled “Error info - $err.info”$err.info - text describing the error
Error reply code - $err.rcode
Section titled “Error reply code - $err.rcode”$err.rcode - recommended reply code
Error reply reason - $err.rreason
Section titled “Error reply reason - $err.rreason”$err.rreason - recommended reply reason phrase
From URI domain - $fd
Section titled “From URI domain - $fd”$fd - reference to domain in URI of ‘From’ header
Alias: $from.domain
From display name - $fn
Section titled “From display name - $fn”$fn - reference to display name of ‘From’ header
From tag - $ft
Section titled “From tag - $ft”$ft - reference to tag parameter of ‘From’ header
From URI - $fu
Section titled “From URI - $fu”$fu - reference to URI of ‘From’ header
Alias: $from
From URI username - $fU
Section titled “From URI username - $fU”$fU - reference to username in URI of ‘From’ header
Alias: $from.user
OpenSIPS Log level - $log_level
Section titled “OpenSIPS Log level - $log_level”$log_level - changes the log level for the current process ; the log level can be set to a new value (see possible values or it can be reset back to the global log level.
This function is very helpful if you are tracing and debugging only a specific piece of code.
Example of usage:
log_level= -1 # errors only.....{......$log_level = 4; # set the debug level of the current process to DBGuac_replace_from(....);$log_level = NULL; # reset the log level of the current process to its default level.......}SIP message buffer - $mb
Section titled “SIP message buffer - $mb”$mb - reference to SIP message buffer
Message Flags - $mf
Section titled “Message Flags - $mf”$mf - displays a list with the message/transaction flags set for the current SIP request
SIP message ID - $mi
Section titled “SIP message ID - $mi”$mi - reference to SIP message id
SIP message length - $ml
Section titled “SIP message length - $ml”$ml - reference to SIP message length
Message flag - $msg.flag
Section titled “Message flag - $msg.flag”$msg.flag(flag_name) - this variable provides read/write access to the value of a single certain message flag (identified by name). The values accepted for writing are 1 (set) and 0 (unset). The returned values are 1/”true” (set) and 0/”false” (unset).
setflag("X"); xlog("---- flag value is $msg.flag(X) \n"); $msg.flag(X) = off; xlog("---- flag value is $msg.flag(X) \n");Message is request - $msg.is_request
Section titled “Message is request - $msg.is_request”$msg.is_request - this variable tells if the current SIP message is a request or not. The returned values are 1/”true” (request) and 0/”false” (reply).
xlog("---- this message is a request: $msg.is_request \n"); if ( $msg.is_request ) xlog("---- yes, it is a request\n");Message type - $msg.type
Section titled “Message type - $msg.type”$msg.type - this variable returns the type of the current message. The returned values are “request” (request) or “reply” (reply).
xlog("---- this message is a SIP $msg.type \n");Domain in SIP Request’s original URI - $od
Section titled “Domain in SIP Request’s original URI - $od”$od - reference to domain in request’s original R-URI
Port of SIP request’s original URI - $op
Section titled “Port of SIP request’s original URI - $op”$op - reference to port of original R-URI
Transport protocol of SIP request original URI - $oP
Section titled “Transport protocol of SIP request original URI - $oP”$oP - reference to transport protocol of original R-URI
SIP Request’s original URI - $ou
Section titled “SIP Request’s original URI - $ou”$ou - reference to request’s original URI
Alias: $ouri
Username in SIP Request’s original URI - $oU
Section titled “Username in SIP Request’s original URI - $oU”$oU - reference to username in request’s original URI
Path header - $path
Section titled “Path header - $path”$path - reference to the Path header body.
Route parameter - $param
Section titled “Route parameter - $param”$param(idx) - retrieves the parameters of the route. The index can be an integer, or a pseudo-variable (index starts at 1).
Example:
route { ... $var(debug) = "DBUG:" route(PRINT_VAR, $var(debug), "param value"); ... }
route[PRINT_VAR] { $var(index) = 2; xlog("$param(1): The parameter value is <$param($var(index))>\n"); }Domain in SIP Request’s P-Preferred-Identity header URI - $pd
Section titled “Domain in SIP Request’s P-Preferred-Identity header URI - $pd”$pd - reference to domain in request’s P-Preferred-Identity header URI (see RFC 3325)
Display Name in SIP Request’s P-Preferred-Identity header - $pn
Section titled “Display Name in SIP Request’s P-Preferred-Identity header - $pn”$pn - reference to Display Name in request’s P-Preferred-Identity header (see RFC 3325)
Process id - $pp
Section titled “Process id - $pp”$pp - reference to process id (pid)
User in SIP Request’s P-Preferred-Identity header URI - $pU
Section titled “User in SIP Request’s P-Preferred-Identity header URI - $pU”$pU - reference to user in request’s P-Preferred-Identity header URI (see RFC 3325)
URI in SIP Request’s P-Preferred-Identity header - $pu
Section titled “URI in SIP Request’s P-Preferred-Identity header - $pu”$pu - reference to URI in request’s P-Preferred-Identity header (see RFC 3325)
Domain in SIP Request’s URI - $rd
Section titled “Domain in SIP Request’s URI - $rd”$rd - reference to domain in request’s URI
Alias: $ruri.domain
Body of request/reply - $rb
Section titled “Body of request/reply - $rb”$rb - reference to the body or a body part of the SIP message
$rb- the whole body of the message (with all the parts)$(rb[*])- same as$rb$(rb[n])- the n-th body belonging to a multi-part body from the beginning of message, starting with index 0$(rb[-n])- the n-th body belonging to a multi-part body from the end of the message, starting with index -1 (the last contact instance)$rb(application/sdp)- get the first SDP body part$(rb(application/isup)[-1])- get the last ISUP body part
Returned code - $rc
Section titled “Returned code - $rc”$rc - reference to returned code by last invoked function
$retcode - same as $rc
Remote-Party-ID header URI - $re
Section titled “Remote-Party-ID header URI - $re”$re - reference to Remote-Party-ID header URI
SIP request’s method - $rm
Section titled “SIP request’s method - $rm”$rm - reference to request’s method
SIP request’s port - $rp
Section titled “SIP request’s port - $rp”$rp - reference to port of R-URI
Transport protocol of SIP request URI - $rP
Section titled “Transport protocol of SIP request URI - $rP”$rP - reference to transport protocol of R-URI
SIP reply’s reason - $rr
Section titled “SIP reply’s reason - $rr”$rr - reference to reply’s reason
SIP reply’s status - $rs
Section titled “SIP reply’s status - $rs”$rs - reference to reply’s status
Refer-to URI - $rt
Section titled “Refer-to URI - $rt”$rt - reference to URI of refer-to header
SIP Request’s URI - $ru
Section titled “SIP Request’s URI - $ru”$ru - reference to request’s URI
Alias: $ruri
Username in SIP Request’s URI - $rU
Section titled “Username in SIP Request’s URI - $rU”$rU - reference to username in request’s URI
Alias: $ruri.user
Q value of the SIP Request’s URI - $ru_q
Section titled “Q value of the SIP Request’s URI - $ru_q”$ru_q - reference to q value of the R-URI
IP source address - $si
Section titled “IP source address - $si”$si - reference to IP source address of the message
Alias: $src_ip
Socket inbound - $socket_in / $socket_in(field)
Section titled “Socket inbound - $socket_in / $socket_in(field)”$socket_in - read-only variable to get the description (proto:ip:port format) of the inbound socket (used for receiving the message).
The variable also offers detailed read-only access to various attributes/sub-fields of the socket, as $socket_in(). The sub-fields of the socket are:
- ip - the IP part of the socket
- port - the port part of the socket
- proto - the name of the protocol of the socket (as “UDP”, “TCP”, etc)
- advertised_ip - the advertised IP part of the socket (it may be NULL if no advertising is done on this particular socket)
- advertised_port - the advertised port part of the socket (it may be NULL if no advertising is done on this particular socket)
- tag - the socket internal tag/alias
- anycast - if the socket uses an anycast IP or not (returns 0 if not, 1 if yes)
- af - the address family of the socket’s IP. It’s value is “INET” if IPv4 or “INET6” if IPv6. For more details on the meaning of these sub-fields, please also read about the socket definition.
Socket outbound - $socket_out / $socket_out(field)
Section titled “Socket outbound - $socket_out / $socket_out(field)”$socket_out - read-write variable for reading or changing the outbound socket of the message. Originally (before being written/changed) it will return the same socket description as $socket_in (the inbound socket will be used as outbound socket also).
The variable also offers detailed read-only access to various attributes/sub-fields of the socket, as $socket_out(). It provides the same sub-fields as the $socket_in variable.
$socket_out = "udp:11.11.11.11:5060"; xlog("The outbound port is $socket_out(port)\n");Source port - $sp
Section titled “Source port - $sp”$sp - reference to the source port of the message
To URI Domain - $td
Section titled “To URI Domain - $td”$td - reference to domain in URI of ‘To’ header
Alias: $to.domain
To display name - $tn
Section titled “To display name - $tn”$tn - reference to display name of ‘To’ header
To tag - $tt
Section titled “To tag - $tt”$tt - reference to tag parameter of ‘To’ header
To URI - $tu
Section titled “To URI - $tu”$tu - reference to URI of ‘To’ header
Alias: $to
To URI Username - $tU
Section titled “To URI Username - $tU”$tU - reference to username in URI of ‘To’ header
Alias: $to.user
Formatted date and time - $time
Section titled “Formatted date and time - $time”$time(format) - returns the string formatted time according to UNIX date (see: man date).
Branch index - $T_branch_idx
Section titled “Branch index - $T_branch_idx”$T_branch_idx - the index (starting with 1 for the first branch) of the branch for which is executed the branch_route[]. If used outside of branch_route[] block, the value is ‘0’. This is exported by TM module.
String formatted time - $Tf
Section titled “String formatted time - $Tf”$Tf - reference string formatted time
Current unix time stamp in seconds - $Ts
Section titled “Current unix time stamp in seconds - $Ts”$Ts - reference to current unix time stamp in seconds
Current microseconds of the current second - $Tsm
Section titled “Current microseconds of the current second - $Tsm”$Tsm - reference to current microseconds of the current second
Startup unix time stamp - $TS
Section titled “Startup unix time stamp - $TS”$TS - reference to startup unix time stamp
User agent header - $ua
Section titled “User agent header - $ua”$ua - reference to user agent header field
SIP Headers - $hdr
Section titled “SIP Headers - $hdr”$(hdr(name)[N]) - represents the body of the N-th header identified by ‘name’. If [N] is omitted then the body of the first header is printed. The first header is retrieved when N=0, for the second N=1, and so on. To print the last header of that type, use -1, no other negative values are supported now. No white spaces are allowed inside the specifier (before }, before or after {, [, ] symbols). When N=’*’, all headers of that type are printed.
The module should identify most of compact header names (the ones recognized by OpenSIPS which should be all at this moment), if not, the compact form has to be specified explicitly. It is recommended to use dedicated specifiers for headers (e.g., %ua for user agent header), if they are available — they are faster.
$(hdr_name[N]) - returns the name of the N-th header. The first header name is obtained for N=0, the second for N=1, and so on. To print the last header name use -1, the second-to-last -2 and so on. No white spaces are allowed inside the specifier (before }, before or after {, [, ] symbols). When N=’*’, all header names are printed.
$(hdrcnt(name)) — returns number of headers of type given by ‘name’. Uses same rules for specifying header names as $hdr(name) above. Many headers (e.g., Via, Path, Record-Route) may appear more than once in the message. This variable returns the number of headers of a given type.
Note that some headers (e.g., Path) may be joined together with commas and appear as a single header line. This variable counts the number of header lines, not header values.
For message fragment below, $hdrcnt(Path) will have value 2 and $(hdr(Path)[0]) will have value <a.com>:
Path: <a.com> Path: <b.com>For message fragment below, $hdrcnt(Path) will have value 1 and $(hdr(Path)[0]) will have value <a.com>,<b.com>:
Path: <a.com>,<b.com>Note that both examples above are semantically equivalent but the variables take on different values.
Route Name (Full) - $route
Section titled “Route Name (Full) - $route”$route - Access route names of the current route call stack. Usage examples (assuming a route call stack of “route > route[A] > route[B]”):
$routeand$(route[0])both return “route[B]” (current route)$(route[1])returns “route[A]” (parent route)$(route[2])returns “route” (previous-parent route)$(route[-1])returns “route” (topmost route)$(route[-2])returns “route[A]” (next-topmost route)$(route[-3])returns “route[B]” (next-next-topmost route)$(route[3])and$(route[-4])both return NULL (index out of bounds)$(route[*])returns “route > route[A] > route[B]” (entire call stack)
Route Type - $route.type
Section titled “Route Type - $route.type”$route.type - Access the type of the current route. May be indexed, using positive or negative indexes.
$route.typeand$(route.type[0])both return current route type$(route.type[1])returns parent route type$(route.type[-1])returns topmost route type$(route.type[-2])returns next-topmost route type
Route Name - $route.name
Section titled “Route Name - $route.name”$route.name - Access the name of the current route. May be indexed, using positive or negative indexes.
$route.nameand$(route.name[0])both return current route name$(route.name[1])returns parent route name$(route.name[-1])returns topmost route name$(route.name[-2])returns next-topmost route name
Current script line and file - $cfg_line
Section titled “Current script line and file - $cfg_line”$cfg_line - Holds the current line from the script of the action being executed, useful for logging purposes
$cfg_file - Holds the current name of the cfg file being executed, useful when using multiple scripts via the include statement
Log level for xlog() - $xlog_level
Section titled “Log level for xlog() - $xlog_level”$xlog_level - allows to set /reset the xlog() logging level on per-process bases. Shortly said, you can read the verbosity level for the xlog() calls or you can temporary change the level per process bases.
Example:
xlog("current verbosity is $xlog_level \n");$xlog_level = L_DBG; # force local xlogging limit to DBG...(set of xlogs)...$xlog_level = NULL; # reset to initial valueEscape Sequences
Section titled “Escape Sequences”These sequences are exported, and mainly used, by xlog module to print messages in many colors (foreground and background) using escape sequences.
Foreground and background colors
Section titled “Foreground and background colors”$C(xy) - reference to an escape sequence. ¿x¿ represents the foreground color and ¿y¿ represents the background color.
Colors could be:
- x : default color of the terminal
- s : Black
- r : Red
- g : Green
- y : Yellow
- b : Blue
- p : Purple
- c : Cyan
- w : White
Examples
Section titled “Examples”A few examples of usage.
...route {... $avp(uuid)="caller_id"; $avp(tmp)= $avp(uuid) + ": " + $fu; xlog("$C(bg)$avp(tmp)$C(xx) [$avp(tmp)] $C(br)$cs$C(xx)=[$hdr(cseq)]\n");...}...