ycp(3) User Contributed Perl Documentation ycp(3)
NAME
ycp - a Perl module for parsing and writing the YaST2 Communication Protocol
SYNOPSIS
"($symbol, @config) = ycp::ParseTerm ('MyAgentConfig ("/etc/file", false, true, $["a":1, "b":2])');"
"($command, $path, $arg) = ycp::ParseCommand ('Write (.magic.path, "abacadabra")');"
"ycp::Return (["arbitrarily", "complex", "data"]);"
DATA
PerlYCPValue
PerlYCPValue is a convention for storing a YCP value in a Perl variable. "ParseYcp" parses YCP string representation into PerlYCPValues.
A PerlYCPValue cannot represent a term but only a term is allowed to initialize an agent in a .scr file. Therefore "ParseTerm" is provided.
string, integer, boolean
Stored as a scalar.
list
Stored as a reference to a list of PerlYCPValues.
map Stored as a reference to a map of PerlYCPValues.
path
Stored as a reference to a string (starting with a "." as expected).
nil (void)
Stored as an undef.
PARSING
ParseCommand
ParseComand $line
"($command, $path, $arg) = ParseCommand ('Write (.moria.gate, "mellon")');"
Parse a SCR command of the form Command (.some.path, optional_argument)
Returns a three element list ("Command", ".some.path", $argument) where the argument is a "PerlYCPValue" and will be undef if it was not
specified. Note that the path is converted to a string.
If there was a parse error, the command or path will be the empty string.
ParseTerm
ParseTerm $line
"($symbol, @config) = ParseTerm ('MyAgentConfig ("/etc/file", false, true, $["a":1, "b":2])');"
Parse a YCP term. Note that there can be no other term inside.
Returns a list whose first element is the term symbol as a string (or "" in case of an error) and the remaining elements are the term
arguments ("PerlYCPValue")
PathComponents
PathComponents $path_ref
($cmd, $path) = ParseCommand ('`Read (.foo."%gconf.d"."gernel")'
@c = PathComponents ($path);
if ($c[0] eq '%gconf.d' && $c[1] eq "gernel") {...}
Converts a path (a string reference, "PerlYCPValue") to a list of its components. It deals with the nontrivial parts of path syntax. On
error it returns undef.
. -> ()
.foo.bar -> ('foo', 'bar')
."foo" -> ('foo')
."double"quote" -> ('double"quote')
."a.dot" -> ('a.dot')
WRITING
Return
"Return (["arbitrarily", "complex", "data"]);"
Sends a "PerlYCPValue" to the partner YCP component.
If there's just one argment, scalars are interpreted this way: "true" or "false" are sent as booleans, integers or strings of digits are
sent as integers, otherwise as strings. If a second argument exists and is true, all scalars are written as strings. If a second argument
exists and is false, all scalars are written as byteblocks.
To send a list, call Return(@list), not Return(@list). Similarly for a map. You can use references to anonymous lists [] and hashes {}.
The difference from "ycpReturn" is that Return can return scalars directly, strings are properly escaped if needeed and paths can be
returned.
LOGGING
If you are running in the main yast process and thus can afford to import YaST::YCP, it is better to use its logging functions because they
use log.conf and logging just works. In such case, you should not need to use ycp.pm at all. Instead, "use YaST::YCP (":LOGGING")".
The log output can now be redirected, which will be useful for test suites. If the first command-line option is "-l", the second argument
is taken as the log file. A hyphen "-" designates standard output.
Otherwise, /var/log/YaST2/y2log and $HOME/.y2log are tried, in that order.
y2debug
y2debug, y2milestone, y2warning, y2error, y2security, y2internal
Logs debug messages to /var/log/YaST2/y2log or $HOME/.y2log
Note a semantic change in y2debug: now the environment variable Y2DEBUG is honored so y2debug will not produce output unless this variable
is set. This is for compatibility with the logging system in libycp.
ycpDoVerboseLog
Enables output of y2verbose which is used in some of the obsolete functions.
OBSOLETE FUNCTIONS
ycpArgIsMap
Obsolete. Use (ref($arg) eq "HASH") instead.
ycpArgIsList
Obsolete. Use (ref($arg) eq "ARRAY") instead.
ycpArgIsInteger
Not really obsolete because the new parser simply treats integers, booleans and strings as scalars. But who cares, nobody used this anyway.
ycpArgIsString
Not really obsolete because the new parser simply treats integers, booleans and strings as scalars. But who cares, nobody used this anyway.
ycpArgIsNil
Obsolete. Use (ref($arg) eq "SCALAR" && $$arg eq "nil") instead.
ycpArgIsNone
Obsolete. Use (defined ($arg)) instead.
ycpCommandIsDir
Obsolete. Use ($command eq "Dir")
ycpCommandIsRead
Obsolete. Use ($command eq "Read")
ycpCommandIsWrite
Obsolete. Use ($command eq "Write")
ycpCommandIsExecute
Obsolete. Use ($command eq "Execute")
ycpCommandIsResult
Obsolete. Use ($command eq "result"), note the lowercase 'r'.
ycpGetCommand
Obsolete. Use the return value of "ParseCommand".
ycpGetPath
Obsolete. Use the return value of "ParseCommand".
ycpGetArgType
Obsolete. Use ref on a return value of "ParseCommand".
Umm, string/integer/boolean?
ycpGetArgMap
Obsolete. See "PerlYCPValue".
ycpGetArgList
Obsolete. See "PerlYCPValue".
ycpGetArgString
Obsolete. See "PerlYCPValue".
ycpGetArgInteger
Obsolete. See PerlYCPValue.
Umm, string/integer/boolean?
ycpReturnSkalarAsInt
Obsolete. Use "Return".
ycpReturnSkalarAsBoolean
Obsolete. Use "Return"("true" or "false")
ycpReturnSkalarAsString
Obsolete. Works only on strings not containing backslashes and quotes that would need escaping.
Use "Return".
ycpReturnArrayAsList
Obsolete. Works only on list of strings not containing backslashes and quotes that would need escaping.
Use "Return".
ycpReturnHashAsMap
Obsolete. Works only on maps of strings not containing backslashes and quotes that would need escaping.
Use "Return".
ycpReturn
Obsolete. Use "Return"
ycpInit
Obsolete. Use "ParseCommand".
perl v5.12.1 2009-08-11 ycp(3)