: gets the values of the keys
+passed in @what from the requested user's environment, returns a hash
+
+=back
+
+=head2 User Roles
+
+=over 4
+
+=item *
+
+allowed($priv,$uri) : check for a user privilege; returns codes for allowed
+actions
+ F: full access
+ U,I,K: authentication modes (cxx only)
+ '': forbidden
+ 1: user needs to choose course
+ 2: browse allowed
+
+=item *
+
+definerole($rolename,$sysrole,$domrole,$courole) : define role; define a custom
+role rolename set privileges in format of lonTabs/roles.tab for system, domain,
+and course level
+
+=item *
+
+plaintext($short) : return value in %prp hash (rolesplain.tab); plain text
+explanation of a user role term
+
+=back
+
+=head2 User Modification
+
+=over 4
+
+=item *
+
+assignrole($udom,$uname,$url,$role,$end,$start) : assign role; give a role to a
+user for the level given by URL. Optional start and end dates (leave empty
+string or zero for "no date")
+
+=item *
+
+changepass($uname,$udom,$currentpass,$newpass,$server) : attempts to
+change a users, password, possible return values are: ok,
+pwchange_failure, non_authorized, auth_mode_error, unknown_user,
+refused
+
+=item *
+
+modifyuserauth($udom,$uname,$umode,$upass) : modify user authentication
+
+=item *
+
+modifyuser($udom,$uname,$uid,$umode,$upass,$first,$middle,$last,$gene) :
+modify user
+
+=item *
+
+modifystudent
+
+modify a students enrollment and identification information.
+The course id is resolved based on the current users environment.
+This means the envoking user must be a course coordinator or otherwise
+associated with a course.
+
+This call is essentially a wrapper for lonnet::modifyuser and
+lonnet::modify_student_enrollment
+
+Inputs:
+
+=over 4
+
+=item B<$udom> Students loncapa domain
+
+=item B<$uname> Students loncapa login name
+
+=item B<$uid> Students id/student number
+
+=item B<$umode> Students authentication mode
+
+=item B<$upass> Students password
+
+=item B<$first> Students first name
+
+=item B<$middle> Students middle name
+
+=item B<$last> Students last name
+
+=item B<$gene> Students generation
+
+=item B<$usec> Students section in course
+
+=item B<$end> Unix time of the roles expiration
+
+=item B<$start> Unix time of the roles start date
+
+=item B<$forceid> If defined, allow $uid to be changed
+
+=item B<$desiredhome> server to use as home server for student
+
+=back
+
+=item *
+
+modify_student_enrollment
+
+Change a students enrollment status in a class. The environment variable
+'role.request.course' must be defined for this function to proceed.
+
+Inputs:
+
+=over 4
+
+=item $udom, students domain
+
+=item $uname, students name
+
+=item $uid, students user id
+
+=item $first, students first name
+
+=item $middle
+
+=item $last
+
+=item $gene
+
+=item $usec
+
+=item $end
+
+=item $start
+
+=back
+
+
+=item *
+
+assigncustomrole($udom,$uname,$url,$rdom,$rnam,$rolename,$end,$start) : assign
+custom role; give a custom role to a user for the level given by URL. Specify
+name and domain of role author, and role name
+
+=item *
+
+revokerole($udom,$uname,$url,$role) : revoke a role for url
+
+=item *
+
+revokecustomrole($udom,$uname,$url,$role) : revoke a custom role
+
+=back
+
+=head2 Course Infomation
+
+=over 4
+
+=item *
+
+coursedescription($courseid) : course description
+
+=item *
+
+courseresdata($coursenum,$coursedomain,@which) : request for current
+parameter setting for a specific course, @what should be a list of
+parameters to ask about. This routine caches answers for 5 minutes.
+
+=back
+
+=head2 Course Modification
+
+=over 4
+
+=item *
+
+writecoursepref($courseid,%prefs) : write preferences (environment
+database) for a course
+
+=item *
+
+createcourse($udom,$description,$url) : make/modify course
+
+=back
+
+=head2 Resource Subroutines
+
+=over 4
+
+=item *
+
+subscribe($fname) : subscribe to a resource, returns URL if possible (probably should use repcopy instead)
+
+=item *
+
+repcopy($filename) : subscribes to the requested file, and attempts to
+replicate from the owning library server, Might return
+HTTP_SERVICE_UNAVAILABLE, HTTP_NOT_FOUND, FORBIDDEN, OK, or
+HTTP_BAD_REQUEST, also attempts to grab the metadata for the
+resource. Expects the local filesystem pathname
+(/home/httpd/html/res/....)
+
+=back
+
+=head2 Resource Information
+
+=over 4
+
+=item *
+
+EXT($varname,$symb,$udom,$uname) : evaluates and returns the value of
+a vairety of different possible values, $varname should be a request
+string, and the other parameters can be used to specify who and what
+one is asking about.
+
+Possible values for $varname are environment.lastname (or other item
+from the envirnment hash), user.name (or someother aspect about the
+user), resource.0.maxtries (or some other part and parameter of a
+resource)
+
+=item *
+
+directcondval($number) : get current value of a condition; reads from a state
+string
+
+=item *
+
+condval($condidx) : value of condition index based on state
+
+=item *
+
+metadata($uri,$what,$liburi,$prefix,$depthcount) : request a
+resource's metadata, $what should be either a specific key, or either
+'keys' (to get a list of possible keys) or 'packages' to get a list of
+packages that this resource currently uses, the last 3 arguments are only used internally for recursive metadata.
+
+this function automatically caches all requests
+
+=item *
+
+metadata_query($query,$custom,$customshow) : make a metadata query against the
+network of library servers; returns file handle of where SQL and regex results
+will be stored for query
+
+=item *
+
+symbread($filename) : return symbolic list entry (filename argument optional);
+returns the data handle
+
+=item *
+
+symbverify($symb,$thisfn) : verifies that $symb actually exists and is
+a possible symb for the URL in $thisfn, returns a 1 on success, 0 on
+failure, user must be in a course, as it assumes the existance of the
+course initi hash, and uses $ENV('request.course.id'}
+
+
+=item *
+
+symbclean($symb) : removes versions numbers from a symb, returns the
+cleaned symb
+
+=item *
+
+is_on_map($uri) : checks if the $uri is somewhere on the current
+course map, user must be in a course for it to work.
+
+=item *
+
+numval($salt) : return random seed value (addend for rndseed)
+
+=item *
+
+rndseed($symb,$courseid,$udom,$uname) : create a random sum; returns
+a random seed, all arguments are optional, if they aren't sent it uses the
+environment to derive them. Note: if symb isn't sent and it can't get one
+from &symbread it will use the current time as its return value
+
+=item *
+
+ireceipt($funame,$fudom,$fucourseid,$fusymb) : return unique,
+unfakeable, receipt
+
+=item *
+
+receipt() : API to ireceipt working off of ENV values; given out to users
+
+=item *
+
+countacc($url) : count the number of accesses to a given URL
+
+=item *
+
+checkout($symb,$tuname,$tudom,$tcrsid) : creates a record of a user having looked at an item, most likely printed out or otherwise using a resource
+
+=item *
+
+checkin($token) : updates that a resource has beeen returned (a hard copy version for instance) and returns the data that $token was Checkout with ($symb, $tuname, $tudom, and $tcrsid)
+
+=item *
+
+expirespread($uname,$udom,$stype,$usymb) : set expire date for spreadsheet
+
+=item *
+
+devalidate($symb) : devalidate temporary spreadsheet calculations,
+forcing spreadsheet to reevaluate the resource scores next time.
+
+=back
+
+=head2 Storing/Retreiving Data
+
+=over 4
+
+=item *
+
+store($storehash,$symb,$namespace,$udom,$uname) : stores hash permanently
+for this url; hashref needs to be given and should be a \%hashname; the
+remaining args aren't required and if they aren't passed or are '' they will
+be derived from the ENV
+
+=item *
+
+cstore($storehash,$symb,$namespace,$udom,$uname) : same as store but
+uses critical subroutine
+
+=item *
+
+restore($symb,$namespace,$udom,$uname) : returns hash for this symb;
+all args are optional
+
+=item *
+
+tmpstore($storehash,$symb,$namespace,$udom,$uname) : storage that
+works very similar to store/cstore, but all data is stored in a
+temporary location and can be reset using tmpreset, $storehash should
+be a hash reference, returns nothing on success
+
+=item *
+
+tmprestore($symb,$namespace,$udom,$uname) : storage that works very
+similar to restore, but all data is stored in a temporary location and
+can be reset using tmpreset. Returns a hash of values on success,
+error string otherwise.
+
+=item *
+
+tmpreset($symb,$namespace,$udom,$uname) : temporary storage reset,
+deltes all keys for $symb form the temporary storage hash.
+
+=item *
+
+get($namespace,$storearr,$udom,$uname) : returns hash with keys from array
+reference filled in from namesp ($udom and $uname are optional)
+
+=item *
+
+del($namespace,$storearr,$udom,$uname) : deletes keys out of array from
+namesp ($udom and $uname are optional)
+
+=item *
+
+dump($namespace,$udom,$uname,$regexp) :
+dumps the complete (or key matching regexp) namespace into a hash
+($udom, $uname and $regexp are optional)
+
+=item *
+
+inc($namespace,$store,$udom,$uname) : increments $store in $namespace.
+$store can be a scalar, an array reference, or if the amount to be
+incremented is > 1, a hash reference.
+
+($udom and $uname are optional)
+
+=item *
+
+put($namespace,$storehash,$udom,$uname) : stores hash in namesp
+($udom and $uname are optional)
+
+=item *
+
+putstore($namespace,$storehash,$udomain,$uname) : stores hash in namesp
+keys used in storehash include version information (e.g., 1:$symb:message etc.) as
+used in records written by &store and retrieved by &restore. This function
+was created for use in editing discussion posts, without incrementing the
+version number included in the key for a particular post. The colon
+separated list of attribute names (e.g., the value associated with the key
+1:keys:$symb) is also generated and passed in the ampersand separated
+items sent to lonnet::reply().
+
+=item *
+
+cput($namespace,$storehash,$udom,$uname) : critical put
+($udom and $uname are optional)
+
+=item *
+
+eget($namespace,$storearr,$udom,$uname) : returns hash with keys from array
+reference filled in from namesp (encrypts the return communication)
+($udom and $uname are optional)
+
+=item *
+
+log($udom,$name,$home,$message) : write to permanent log for user; use
+critical subroutine
+
+=back
+
+=head2 Network Status Functions
+
+=over 4
+
+=item *
+
+dirlist($uri) : return directory list based on URI
+
+=item *
+
+spareserver() : find server with least workload from spare.tab
+
+=back
+
+=head2 Apache Request
+
+=over 4
+
+=item *
+
+ssi($url,%hash) : server side include, does a complete request cycle on url to
+localhost, posts hash
+
+=back
+
+=head2 Data to String to Data
+
+=over 4
+
+=item *
+
+hash2str(%hash) : convert a hash into a string complete with escaping and '='
+and '&' separators, supports elements that are arrayrefs and hashrefs
+
+=item *
+
+hashref2str($hashref) : convert a hashref into a string complete with
+escaping and '=' and '&' separators, supports elements that are
+arrayrefs and hashrefs
+
+=item *
+
+arrayref2str($arrayref) : convert an arrayref into a string complete
+with escaping and '&' separators, supports elements that are arrayrefs
+and hashrefs
+
+=item *
+
+str2hash($string) : convert string to hash using unescaping and
+splitting on '=' and '&', supports elements that are arrayrefs and
+hashrefs
+
+=item *
+
+str2array($string) : convert string to hash using unescaping and
+splitting on '&', supports elements that are arrayrefs and hashrefs
+
+=back
+
+=head2 Logging Routines
+
+=over 4
+
+These routines allow one to make log messages in the lonnet.log and
+lonnet.perm logfiles.
+
+=item *
+
+logtouch() : make sure the logfile, lonnet.log, exists
+
+=item *
+
+logthis() : append message to the normal lonnet.log file, it gets
+preiodically rolled over and deleted.
+
+=item *
+
+logperm() : append a permanent message to lonnet.perm.log, this log
+file never gets deleted by any automated portion of the system, only
+messages of critical importance should go in here.
+
+=back
+
+=head2 General File Helper Routines
+
+=over 4
+
+=item *
+
+getfile($file,$caller) : two cases - requests for files in /res or in /uploaded.
+(a) files in /uploaded
+ (i) If a local copy of the file exists -
+ compares modification date of local copy with last-modified date for
+ definitive version stored on home server for course. If local copy is
+ stale, requests a new version from the home server and stores it.
+ If the original has been removed from the home server, then local copy
+ is unlinked.
+ (ii) If local copy does not exist -
+ requests the file from the home server and stores it.
+
+ If $caller is 'uploadrep':
+ This indicates a call from lonuploadrep.pm (PerlHeaderParserHandler phase)
+ for request for files originally uploaded via DOCS.
+ - returns 'ok' if fresh local copy now available, -1 otherwise.
+
+ Otherwise:
+ This indicates a call from the content generation phase of the request.
+ - returns the entire contents of the file or -1.
+
+(b) files in /res
+ - returns the entire contents of a file or -1;
+ it properly subscribes to and replicates the file if neccessary.
+
+=item *
+
+filelocation($dir,$file) : returns file system location of a file
+based on URI; meant to be "fairly clean" absolute reference, $dir is a
+directory that relative $file lookups are to looked in ($dir of /a/dir
+and a file of ../bob will become /a/bob)
+
+=item *
+
+hreflocation($dir,$file) : returns file system location or a URL; same as
+filelocation except for hrefs
+
+=item *
+
+declutter() : declutters URLs (remove docroot, beginning slashes, 'res' etc)
+
+=back
+
+=head2 HTTP Helper Routines
+
+=over 4
+
+=item *
+
+escape() : unpack non-word characters into CGI-compatible hex codes
+
+=item *
+
+unescape() : pack CGI-compatible hex codes into actual non-word ASCII character
+
+=back
+
+=head1 PRIVATE SUBROUTINES
+
+=head2 Underlying communication routines (Shouldn't call)
+
+=over 4
+
+=item *
+
+subreply() : tries to pass a message to lonc, returns con_lost if incapable
+
+=item *
+
+reply() : uses subreply to send a message to remote machine, logs all failures
+
+=item *
+
+critical() : passes a critical message to another server; if cannot
+get through then place message in connection buffer directory and
+returns con_delayed, if incapable of saving message, returns
+con_failed
+
+=item *
+
+reconlonc() : tries to reconnect lonc client processes.
+
+=back
+
+=head2 Resource Access Logging
+
+=over 4
+
+=item *
+
+flushcourselogs() : flush (save) buffer logs and access logs
+
+=item *
+
+courselog($what) : save message for course in hash
+
+=item *
+
+courseacclog($what) : save message for course using &courselog(). Perform
+special processing for specific resource types (problems, exams, quizzes, etc).
+
+=item *
+
+goodbye() : flush course logs and log shutting down; it is called in srm.conf
+as a PerlChildExitHandler
+
+=back
+
+=head2 Other
+
+=over 4
+
+=item *
+
+symblist($mapname,%newhash) : update symbolic storage links
+
+=back
+
+=cut
500 Internal Server Error
Internal Server Error
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misconfiguration and was unable to complete
your request.
Please contact the server administrator at
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