classads - HTCondor Manual
ClassAds are a flexible mechanism for representing the
characteristics and constraints of machines and jobs in the HTCondor system.
ClassAds are used extensively in the HTCondor system to represent jobs,
resources, submitters and other HTCondor daemons. An understanding of this
mechanism is required to harness the full flexibility of the HTCondor
system.
A ClassAd is a set of uniquely named expressions. Each named
expression is called an attribute. The following shows ten attributes, a
portion of an example ClassAd.
MyType = "Machine"
TargetType = "Job"
Machine = "froth.cs.wisc.edu"
Arch = "INTEL"
OpSys = "LINUX"
Disk = 35882
Memory = 128
KeyboardIdle = 173
LoadAvg = 0.1000
Requirements = TARGET.Owner=="smith" || LoadAvg<=0.3 && KeyboardIdle>15*60
ClassAd expressions look very much like expressions in C, and are
composed of literals and attribute references composed with operators and
functions. The difference between ClassAd expressions and C expressions
arise from the fact that ClassAd expressions operate in a much more dynamic
environment. For example, an expression from a machine's ClassAd may refer
to an attribute in a job's ClassAd, such as TARGET.Owner in the above
example. The value and type of the attribute is not known until the
expression is evaluated in an environment which pairs a specific job ClassAd
with the machine ClassAd.
ClassAd expressions handle these uncertainties by defining all
operators to be total operators, which means that they have well defined
behavior regardless of supplied operands. This functionality is provided
through two distinguished values, UNDEFINED and ERROR, and
defining all operators so that they can operate on all possible values in
the ClassAd system. For example, the multiplication operator which usually
only operates on numbers, has a well defined behavior if supplied with
values which are not meaningful to multiply. Thus, the expression 10 *
"A string" evaluates to the value ERROR. Most operators are
strict with respect to ERROR, which means that they evaluate to
ERROR if any of their operands are ERROR. Similarly, most
operators are strict with respect to UNDEFINED.
ClassAds have existed for quite some time in two forms: Old and
New. Old ClassAds were the original form and were used in HTCondor until
HTCondor version 7.5.0. They were heavily tied to the HTCondor development
libraries. New ClassAds added new features and were designed as a
stand-alone library that could be used apart from HTCondor.
In HTCondor version 7.5.1, HTCondor switched to using the New
ClassAd library for all use of ClassAds within HTCondor. The library is
placed into a compatibility mode so that HTCondor 7.5.1 is still able to
exchange ClassAds with older versions of HTCondor.
All user interaction with tools (such as condor_q) as well
as output of tools is still compatible with Old ClassAds. Before HTCondor
version 7.5.1, New ClassAds were used only in the Job Router. There are some
syntax and behavior differences between Old and New ClassAds, all of which
should remain invisible to users of HTCondor.
A complete description of New ClassAds can be found at
http://htcondor.org/classad/classad.html, and in the ClassAd Language
Reference Manual found on that web page.
Some of the features of New ClassAds that are not in Old ClassAds
are lists, nested ClassAds, time values, and matching groups of ClassAds.
HTCondor has avoided using these features, as using them makes it difficult
to interact with older versions of HTCondor. But, users can start using them
if they do not need to interact with versions of HTCondor older than
7.5.1.
The syntax varies slightly between Old and New ClassAds. Here is
an example ClassAd presented in both forms. The Old form:
Foo = 3
Bar = "ab\"cd\ef"
Moo = Foo =!= Undefined
The New form:
[
Foo = 3;
Bar = "ab\"cd\\ef";
Moo = Foo isnt Undefined;
]
HTCondor will convert to and from Old ClassAd syntax as
needed.
Expressions often refer to ClassAd attributes. These attribute
references work differently in Old ClassAds as compared with New ClassAds.
In New ClassAds, an unscoped reference is looked for only in the local
ClassAd. An unscoped reference is an attribute that does not have a
MY. or TARGET. prefix. The local ClassAd may be described by
an example. Matchmaking uses two ClassAds: the job ClassAd and the machine
ClassAd. The job ClassAd is evaluated to see if it is a match for the
machine ClassAd. The job ClassAd is the local ClassAd. Therefore, in the
Requirements attribute of the job ClassAd, any attribute without the
prefix TARGET. is looked up only in the job ClassAd. With New ClassAd
evaluation, the use of the prefix MY. is eliminated, as an unscoped
reference can only refer to the local ClassAd.
The MY. and TARGET. scoping prefixes only apply when
evaluating an expression within the context of two ClassAds. Two examples
that exemplify this are matchmaking and machine policy evaluation. When
evaluating an expression within the context of a single ClassAd, MY.
and TARGET. are not defined. Using them within the context of a
single ClassAd will result in a value of Undefined. Two examples that
exemplify evaluating an expression within the context of a single ClassAd
are during user job policy evaluation, and with the -constraint
option to command-line tools.
New ClassAds have no CurrentTime attribute. If needed, use
the time() function instead. In order to mimic Old ClassAd semantics in
current versions of HTCondor, all ClassAds have an implicit
CurrentTime attribute, with a value of time().
In current versions of HTCondor, New ClassAds will mimic the
evaluation behavior of Old ClassAds. No configuration variables or submit
description file contents should need to be changed. To eliminate this
behavior and use only the semantics of New ClassAds, set the configuration
variable STRICT_CLASSAD_EVALUATION to True. This permits
testing expressions to see if any adjustment is required, before a future
version of HTCondor potentially makes New ClassAds evaluation behavior the
default or the only option.
ClassAd expressions are formed by composing literals, attribute
references and other sub-expressions with operators and functions.
Literals in the ClassAd language may be of integer, real, string,
undefined or error types. The syntax of these literals is as follows:
- Integer
- A sequence of continuous digits (i.e., [0-9]). Additionally, the keywords
TRUE and FALSE (case insensitive) are syntactic representations of the
integers 1 and 0 respectively.
- Real
- Two sequences of continuous digits separated by a period (i.e.,
[0-9]+.[0-9]+).
- String
- A double quote character, followed by a list of characters terminated by a
double quote character. A backslash character inside the string causes the
following character to be considered as part of the string, irrespective
of what that character is.
- Undefined
- The keyword UNDEFINED (case insensitive) represents the
UNDEFINED value.
- Error
- The keyword ERROR (case insensitive) represents the ERROR
value.
Every expression in a ClassAd is named by an attribute name.
Together, the (name,expression) pair is called an attribute. An attribute
may be referred to in other expressions through its attribute name.
Attribute names are sequences of alphabetic characters, digits and
underscores, and may not begin with a digit. All characters in the name are
significant, but case is not significant. Thus, Memory, memory and MeMoRy
all refer to the same attribute.
An attribute reference consists of the name of the attribute being
referenced, and an optional scope resolution prefix. The prefixes that may
be used are MY. and TARGET.. The case used for these prefixes
is not significant. The semantics of supplying a prefix are discussed in
classads/classad-mechanism:classad evaluation semantics.
The operators that may be used in ClassAd expressions are similar
to those available in C. The available operators and their relative
precedence is shown in the following example:
- (unary negation) (high precedence)
* / %
+ - (addition, subtraction)
< <= >= >
== != =?= is =!= isnt
&&
|| (low precedence)
The operator with the highest precedence is the unary minus
operator. The only operators which are unfamiliar are the =?=, is, =!= and
isnt operators, which are discussed in classads/classad-mechanism:classad
evaluation semantics.
Any ClassAd expression may utilize predefined functions. Function
names are case insensitive. Parameters to functions and a return value from
a function may be typed (as given) or not. Nested or recursive function
calls are allowed.
Here are descriptions of each of these predefined functions. The
possible types are the same as itemized in
classads/classad-mechanism:classad syntax. Where the type may be any of
these literal types, it is called out as AnyType. Where the type is Integer,
but only returns the value 1 or 0 (implying True or False), it
is called out as Boolean. The format of each function is given as
ReturnType FunctionName(ParameterType parameter1, ParameterType parameter2, ...)
Optional parameters are given within square brackets.
- AnyType
eval(AnyType Expr)
- Evaluates Expr as a string and then returns the result of
evaluating the contents of the string as a ClassAd expression. This is
useful when referring to an attribute such as slotX_State where
X, the desired slot number is an expression, such as
SlotID+10. In such a case, if attribute SlotID is 5, the
value of the attribute slot15_State can be referenced using the
expression eval(strcat("slot",
SlotID+10,"_State")). Function strcat() calls function
string() on the second parameter, which evaluates the expression, and then
converts the integer result 15 to the string "15". The
concatenated string returned by strcat() is
"slot15_State", and this string is then evaluated.
Note that referring to attributes of a job from within the
string passed to eval() in the Requirements or Rank
expressions could cause inaccuracies in HTCondor's automatic
auto-clustering of jobs into equivalent groups for matchmaking purposes.
This is because HTCondor needs to determine which ClassAd attributes are
significant for matchmaking purposes, and indirect references from
within the string passed to eval() will not be counted.
- String unparse(Attribute attr)
- This function looks up the value of the provided attribute and returns the
unparsed version as a string. The attribute's value is not evaluated. If
the attribute's value is x + 3, then the function would return the
string "x + 3". If the provided attribute cannot be
found, an empty string is returned.
This function returns ERROR if other than exactly 1
argument is given or the argument is not an attribute reference.
- String unresolved(Attribute attr)
- This function returns the external attribute references and unresolved
attribute references of the expression that is the value of the provided
attribute. If the provided attribute cannot be found, then
undefined is returned.
For example, in a typical job ClassAd if the
Requirements expression has the value OpSys ==
"LINUX" && TARGET.Arch == "ARM" &&
Cpus >= RequestCpus, then unresolved(Requirements) will
return "Arch,Cpus,OpSys" because those will not be
attributes of the job ClassAd.
- Boolean
unresolved(Attribute attr, String pattern)
- This function returns True when at least one of the external or
unresolved attribute references of the expression that is the value of the
provided attribute matches the given Perl regular expression pattern. If
none of the references match the pattern, then False is returned.
If the provided attribute cannot be found, then undefined is
returned.
For example, in a typical job ClassAd if the
Requirements expression has the value OpSys ==
"LINUX" && Arch == "ARM", then
unresolved(Requirements, "^OpSys") will return
True, and unresolved(Requirements, "OpSys.+")
will return False.
The intended use of this function is to make it easier to
apply a submit transform to a job only when the job does not already
reference a certain attribute. For instance
JOB_TRANSFORM_DefPlatform @=end
# Apply this transform only when the job requirements does not reference OpSysAndver or OpSysName
REQUIREMENTS ! unresolved(Requirements, "OpSys.+")
# Add a clause to the job requirements to match only CentOs7 machines
SET Requirements $(MY.Requirements) && OpSysAndVer == "CentOS7"
@end
- AnyType
ifThenElse(AnyType IfExpr,AnyType ThenExpr, AnyType
ElseExpr)
- A conditional expression is described by IfExpr. The following
defines return values, when IfExpr evaluates to
- True. Evaluate and return the value as given by
ThenExpr.
- False. Evaluate and return the value as given by
ElseExpr.
- UNDEFINED. Return the value UNDEFINED.
- ERROR. Return the value ERROR.
- 0.0. Evaluate, and return the value as given by
ElseExpr.
- non-0.0 Real values. Evaluate, and return the value as given by
ThenExpr.
Where IfExpr evaluates to give a value of type
String, the function returns the value ERROR. The
implementation uses lazy evaluation, so expressions are only evaluated as
defined.
This function returns ERROR if other than exactly 3
arguments are given.
- Boolean
isUndefined(AnyType Expr)
- Returns True, if Expr evaluates to UNDEFINED. Returns
False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isError(AnyType Expr)
- Returns True, if Expr evaluates to ERROR. Returns
False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isString(AnyType Expr)
- Returns True, if the evaluation of Expr gives a value of
type String. Returns False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isInteger(AnyType Expr)
- Returns True, if the evaluation of Expr gives a value of
type Integer. Returns False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isReal(AnyType Expr)
- Returns True, if the evaluation of Expr gives a value of
type Real. Returns False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isList(AnyType Expr)
- Returns True, if the evaluation of Expr gives a value of
type List. Returns False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isClassAd(AnyType Expr)
- Returns True, if the evaluation of Expr gives a value of
type ClassAd. Returns False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isBoolean(AnyType Expr)
- Returns True, if the evaluation of Expr gives the integer
value 0 or 1. Returns False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isAbstime(AnyType Expr)
- Returns True, if the evaluation of Expr returns an abstime
type. Returns False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
isReltime(AnyType Expr)
- Returns True, if the evaluation of Expr returns an relative
time type. Returns False in all other cases.
This function returns ERROR if other than exactly 1
argument is given.
- Boolean
member(AnyType m, ListType l)
- Returns error if m does not evalute to a scalar, or l does not evaluate to
a list. Otherwise the elements of l are evaluted in order, and if an
element is equal to m in the sense of == the result of the function
is True. Otherwise the function returns false.
- Boolean
anyCompare(string op, list l, AnyType t)
- Returns error if op does not evalute to one of <, <=,
==, >, >=, !-, is or isnt.
Returns error if l isn't a list, or t isn't a scalar Otherwise the
elements of l are evaluted and compared to t using the corresponding
operator defined by op. If any of the members of l evaluate to true, the
result is True. Otherwise the function returns False.
- Boolean
allCompare(string op, list l, AnyType t)
- Returns error if op does not evalute to one of <, <=,
==, >, >=, !-, is or isnt.
Returns error if l isn't a list, or t isn't a scalar Otherwise the
elements of l are evaluted and compared to t using the corresponding
operator defined by op. If all of the members of l evaluate to true, the
result is True. Otherwise the function returns False.
- Boolean
identicalMember(AnyType m, ListType l)
- Returns error if m does not evalute to a scalar, or l does not evaluate to
a list. Otherwise the elements of l are evaluted in order, and if an
element is equal to m in the sense of =?= the result of the
function is True. Otherwise the function returns false.
- Integer int(AnyType Expr)
- Returns the integer value as defined by Expr. Where the type of the
evaluated Expr is Real, the value is truncated (round
towards zero) to an integer. Where the type of the evaluated Expr
is String, the string is converted to an integer using a C-like
atoi() function. When this result is not an integer, ERROR is
returned. Where the evaluated Expr is ERROR or
UNDEFINED, ERROR is returned.
This function returns ERROR if other than exactly 1
argument is given.
- Real real(AnyType Expr)
- Returns the real value as defined by Expr. Where the type of the
evaluated Expr is Integer, the return value is the converted
integer. Where the type of the evaluated Expr is String, the
string is converted to a real value using a C-like atof() function. When
this result is not a real, ERROR is returned. Where the evaluated
Expr is ERROR or UNDEFINED, ERROR is returned.
This function returns ERROR if other than exactly 1
argument is given.
- String string(AnyType Expr)
- Returns the string that results from the evaluation of Expr.
Converts a non-string value to a string. Where the evaluated Expr
is ERROR or UNDEFINED, ERROR is returned.
This function returns ERROR if other than exactly 1
argument is given.
- Bool bool(AnyType
Expr)
- Returns the boolean that results from the evaluation of Expr.
Converts a non-boolean value to a bool. A string expression that evaluates
to the string "true" yields true, and "false" returns
This function returns ERROR if other than exactly 1
argument is given.
- AbsTime
absTime(AnyType t [, int z])
- Creates an AbsTime value corresponding to time t an time-zone offset z. If
t is a String, then z must be omitted, and t is parsed as a specification
as follows.
The operand t is parsed as a specification of an instant in
time (date and time). This function accepts the canonical native
representation of AbsTime values, but minor variations in format are
allowed. The default format is yyyy-mm-ddThh:mm:sszzzzz where zzzzz is a
time zone in the format +hh:mm or -hh:mm
If t and z are both omitted, the result is an AbsTime value
representing the time and place where the function call is evaluated.
Otherwise, t is converted to a Real by the function
“real”, and treated as a number of seconds from the epoch,
Midnight January 1, 1970 UTC. If z is specified, it is treated as a
number of seconds east of Greenwich. Otherwise, the offset is calculated
from t according to the local rules for the place where the function is
evaluated.
- RelTime
relTime(AnyType t)
- If the operand t is a String, it is parsed as a specification of a time
interval. This function accepts the canonical native representation of
RelTime values, but minor variations in format are allowed.
Otherwise, t is converted to a Real by the function real, and
treated as a number of seconds. The default string format is
[-]days+hh:mm:ss.fff, where leading components and the fraction .fff are
omitted if they are zero. In the default syntax, days is a sequence of
digits starting with a non-zero digit, hh, mm, and ss are strings of
exactly two digits (padded on the left with zeros if necessary) with
values less than 24, 60, and 60, respectively and fff is a string of
exactly three digits.
- Integer floor(AnyType Expr)
- Returns the integer that results from the evaluation of Expr, where
the type of the evaluated Expr is Integer. Where the type of
the evaluated Expr is not Integer, function
real(Expr) is called. Its return value is then used to return the
largest magnitude integer that is not larger than the returned value.
Where real(Expr) returns ERROR or UNDEFINED,
ERROR is returned.
This function returns ERROR if other than exactly 1
argument is given.
- Integer ceiling(AnyType Expr)
- Returns the integer that results from the evaluation of Expr, where
the type of the evaluated Expr is Integer. Where the type of
the evaluated Expr is not Integer, function
real(Expr) is called. Its return value is then used to return the
smallest magnitude integer that is not less than the returned value. Where
real(Expr) returns ERROR or UNDEFINED, ERROR
is returned.
This function returns ERROR if other than exactly 1
argument is given.
- Integer pow(Integer base, Integer exponent) OR Real
pow(Integer base, Integer exponent) OR Real pow(Real base, Real
exponent)
- Calculates base raised to the power of exponent. If
exponent is an integer value greater than or equal to 0, and
base is an integer, then an integer value is returned. If
exponent is an integer value less than 0, or if either base
or exponent is a real, then a real value is returned. An invocation
with exponent=0 or exponent=0.0, for any value of
base, including 0 or 0.0, returns the value 1 or 1.0, type
appropriate.
- Integer quantize(AnyType a, Integer b) OR Real
quantize(AnyType a, Real b) OR AnyType quantize(AnyType a, AnyType
list b)
- quantize() computes the quotient of a/b, in order to further
compute `` ceiling(quotient) * b``. This computes and returns an integral
multiple of b that is at least as large as a. So, when b
>= a, the return value will be b. The return type is the
same as that of b, where b is an Integer or Real.
When b is a list, quantize() returns the first
value in the list that is greater than or equal to a. When no
value in the list is greater than or equal to a, this computes
and returns an integral multiple of the last member in the list that is
at least as large as a.
This function returns ERROR if a or b, or
a member of the list that must be considered is not an Integer or
Real.
Here are examples:
8 = quantize(3, 8)
4 = quantize(3, 2)
0 = quantize(0, 4)
6.8 = quantize(1.5, 6.8)
7.2 = quantize(6.8, 1.2)
10.2 = quantize(10, 5.1)
4 = quantize(0, {4})
2 = quantize(2, {1, 2, "A"})
3.0 = quantize(3, {1, 2, 0.5})
3.0 = quantize(2.7, {1, 2, 0.5})
ERROR = quantize(3, {1, 2, "A"})
- Integer round(AnyType Expr)
- Returns the integer that results from the evaluation of Expr, where
the type of the evaluated Expr is Integer. Where the type of
the evaluated Expr is not Integer, function
real(Expr) is called. Its return value is then used to return the
integer that results from a round-to-nearest rounding method. The nearest
integer value to the return value is returned, except in the case of the
value at the exact midpoint between two integer values. In this case, the
even valued integer is returned. Where real(Expr) returns
ERROR or UNDEFINED, or the integer value does not fit into
32 bits, ERROR is returned.
This function returns ERROR if other than exactly 1
argument is given.
- Integer random([ AnyType Expr ])
- Where the optional argument Expr evaluates to type Integer
or type Real (and called x), the return value is the integer
or real r randomly chosen from the interval 0 <= r <
x. With no argument, the return value is chosen with
random(1.0). Returns ERROR in all other cases.
This function returns ERROR if greater than 1 argument
is given.
- Number sum([ List l
])
- The elements of l are evaluated, producing a list l of values. Undefined
values are removed. If the resulting l is composed only of numbers, the
result is the sum of the values, as a Real if any value is Real, and as an
Integer otherwise. If the list is empty, the result is 0. If the list has
only Undefined values, the result is UNDEFINED. In other cases, the
result is ERROR.
This function returns ERROR if greater than 1 argument
is given.
- Number avg([
List l ])
- The elements of l are evaluated, producing a list l of values. Undefined
values are removed. If the resulting l is composed only of numbers, the
result is the average of the values, as a Real. If the list is empty, the
result is 0. If the list has only Undefined values, the result is
UNDEFINED. In other cases, the result is ERROR.
- Number min([
List l ])
- The elements of l are evaluated, producing a list l of values. Undefined
values are removed. If the resulting l is composed only of numbers, the
result is the minimum of the values, as a Real if any value is Real, and
as an Integer otherwise. If the list is empty, the result is UNDEFINED. In
other cases, the result is ERROR.
- Number max([
List l ])
- The elements of l are evaluated, producing a list l of values. Undefined
values are removed. If the resulting l is composed only of numbers, the
result is the maximum of the values, as a Real if any value is Real, and
as an Integer otherwise. If the list is empty, the result is UNDEFINED. In
other cases, the result is ERROR.
- String strcat(AnyType Expr1 [ , AnyType Expr2 ...])
- Returns the string which is the concatenation of all arguments, where all
arguments are converted to type String by function
string(Expr). Returns ERROR if any argument evaluates to
UNDEFINED or ERROR.
- String join(String sep, AnyType Expr1 [ , AnyType Expr2 ...]) OR
String join(String sep, List list OR String join(List
list
- Returns the string which is the concatenation of all arguments after the
first one. The first argument is the separator, and it is inserted between
each of the other arguments during concatenation. All arguments which are
not undefined are converted to type String by function
string(Expr) before concatenation. Undefined arguments are skipped.
When there are exactly two arguments, If the second argument is a List,
all members of the list are converted to strings and then joined using the
separator. When there is only one argument, and the argument is a List,
all members of the list are converted to strings and then concatenated.
Returns ERROR if any argument evaluates to
UNDEFINED or ERROR.
For example:
"a, b, c" = join(", ", "a", "b", "c")
"abc" = join(split("a b c"))
"a;b;c" = join(";", split("a b c"))
- String substr(String s, Integer offset [ , Integer length
])
- Returns the substring of s, from the position indicated by
offset, with (optional) length characters. The first
character within s is at offset 0. If the optional length
argument is not present, the substring extends to the end of the string.
If offset is negative, the value (length - offset) is used
for the offset. If length is negative, an initial substring is
computed, from the offset to the end of the string. Then, the absolute
value of length characters are deleted from the right end of the
initial substring. Further, where characters of this resulting substring
lie outside the original string, the part that lies within the original
string is returned. If the substring lies completely outside of the
original string, the null string is returned.
This function returns ERROR if greater than 3 or less
than 2 arguments are given.
- Integer strcmp(AnyType Expr1, AnyType Expr2)
- Both arguments are converted to type String by function
string(Expr). The return value is an integer that will be
- less than 0, if Expr1 is lexicographically less than
Expr2
- equal to 0, if Expr1 is lexicographically equal to
Expr2
- greater than 0, if Expr1 is lexicographically greater than
Expr2
Case is significant in the comparison. Where either argument
evaluates to ERROR or UNDEFINED, ERROR is returned.
This function returns ERROR if other than 2 arguments are
given.
- Integer stricmp(AnyType Expr1, AnyType Expr2)
- This function is the same as strcmp, except that letter case is not
significant.
- Integer versioncmp(String left, String right)
- This function version-compares two strings. It returns an integer
- less than zero if left is an earlier version than right
- zero if the strings are identical
- more than zero if left is a later version than right.
A version comparison is a lexicographic comparison unless the
first difference between the two strings occurs in a string of digits, in
which case, sort by the value of that number (assuming that more leading
zeroes mean smaller numbers). Thus 7.x is earlier than 7.y,
7.9 is earlier than 7.10, and the following sequence is in
order: 000, 00, 01, 010, 09, 0, 1, 9, 10.
Boolean versionGT(String left, String right) Boolean
versionLT(String left, String right) Boolean versionGE(String left,
String right) Boolean versionLE(String left, String right)
Boolean versionEQ(String left, String right)
As versioncmp() (above), but for a specific
comparison and returning a boolean. The two letter codes stand for
"Greater Than", "Less Than", "Greater than or
Equal", "Less than or Equal", and "EQual",
respectively.
Boolean version_in_range(String version, String min, String
max)
Equivalent to versionLE(min, version) &&
versionLE(version, max).
- String toUpper(AnyType Expr)
- The single argument is converted to type String by function
string(Expr). The return value is this string, with all lower case
letters converted to upper case. If the argument evaluates to ERROR
or UNDEFINED, ERROR is returned.
This function returns ERROR if other than exactly 1
argument is given.
- String toLower(AnyType Expr)
- The single argument is converted to type String by function
string(Expr). The return value is this string, with all upper case
letters converted to lower case. If the argument evaluates to ERROR
or UNDEFINED, ERROR is returned.
This function returns ERROR if other than exactly 1
argument is given.
- Integer size(AnyType Expr)
- If Expr evaluates to a string, return the number of characters in the
string. If Expr evaluate to a list, return the number of elements in the
list. If Expr evaluate to a classad, return the number of entries in the
ad. Otherwise, ERROR is returned.
- List split(String s [ ,
String tokens ] )
- Returns a list of the substrings of s that have been split up by
using any of the characters within string tokens. If tokens
is not specified, then all white space characters are used to delimit the
string.
- List
splitUserName(String Name)
- Returns a list of two strings. Where Name includes an @
character, the first string in the list will be the substring that comes
before the @ character, and the second string in the list will be
the substring that comes after. Thus, if Name is
"user@domain", then the returned list will be
{"user", "domain"}. If there is no @ character
in Name, then the first string in the list will be Name, and
the second string in the list will be the empty string. Thus, if
Name is "username", then the returned list will be
{"username", ""}.
- List
splitSlotName(String Name)
- Returns a list of two strings. Where Name includes an @
character, the first string in the list will be the substring that comes
before the @ character, and the second string in the list will be
the substring that comes after. Thus, if Name is
"slot1@machine", then the returned list will be
{"slot1", "machine"}. If there is no @
character in Name, then the first string in the list will be the
empty string, and the second string in the list will be Name, Thus,
if Name is "machinename", then the returned list
will be {"", "machinename"}.
- Integer time()
- Returns the current coordinated universal time. This is the time, in
seconds, since midnight of January 1, 1970.
- String formatTime([ Integer time ] [ , String format ])
- Returns a formatted string that is a representation of time. The
argument time is interpreted as coordinated universal time in
seconds, since midnight of January 1, 1970. If not specified, time
will default to the current time.
The argument format is interpreted similarly to the
format argument of the ANSI C strftime function. It consists of
arbitrary text plus placeholders for elements of the time. These
placeholders are percent signs (%) followed by a single letter. To have
a percent sign in the output, use a double percent sign (%%). If
format is not specified, it defaults to %c.
Because the implementation uses strftime() to implement this,
and some versions implement extra, non-ANSI C options, the exact options
available to an implementation may vary. An implementation is only
required to implement the ANSI C options, which are:
- %a
- abbreviated weekday name
- %A
- full weekday name
- %b
- abbreviated month name
- %B
- full month name
- %c
- local date and time representation
- %d
- day of the month (01-31)
- %H
- hour in the 24-hour clock (0-23)
- %I
- hour in the 12-hour clock (01-12)
- %j
- day of the year (001-366)
- %m
- month (01-12)
- %M
- minute (00-59)
- %p
- local equivalent of AM or PM
- %S
- second (00-59)
- %U
- week number of the year (Sunday as first day of week) (00-53)
- %w
- weekday (0-6, Sunday is 0)
- %W
- week number of the year (Monday as first day of week) (00-53)
- %x
- local date representation
- %X
- local time representation
- %y
- year without century (00-99)
- %Y
- year with century
- %Z
- time zone name, if any
- String interval(Integer seconds)
- Uses seconds to return a string of the form days+hh:mm:ss.
This represents an interval of time. Leading values that are zero are
omitted from the string. For example, seconds of 67 becomes
"1:07". A second example, seconds of 1472523 =
17*24*60*60 + 1*60*60 + 2*60 + 3, results in the string
"17+1:02:03".
- String evalInEachContext(Expression expr, List
contexts)
- This function evaluates its first argument as an expression in the context
of each Classad in the second argument and returns a list that is the
result of each evaluation. The first argument should be an expression. If
the second argument does not evaluate to a list of ClassAds, ERROR
is returned.
For example:
{true, false} = evalInEachContext(Prio > 2, { [Prio=3;], [Prio=1;] })
{3, 1} = evalInEachContext(Prio, { [Prio=3;], [Prio=1;] })
ERROR = evalInEachContext(Prio > 2, { [Prio=3;], UNDEFINED })
ERROR = evalInEachContext(Prio > 2, UNDEFINED)
- String countMatches(Expression expr, List contexts)
- This function evaluates its first argument as an expression in the context
of each Classad in the second argument and returns a count of the results
that evaluated to True. The first argument should be an expression.
The second argument should be a list of ClassAds or a list of attribute
references to classAds, or should evaluate to a list of ClassAds. This
function will always return a integer value when the first argument is
defined and the second argument is not ERROR.
For example:
1 = countMatches(Prio > 2, { [Prio=3;], [Prio=1;] })
1 = countMatches(Prio > 2, { [Prio=3;], UNDEFINED })
0 = countMatches(Prio > 2, UNDEFINED)
- AnyType
debug(AnyType expression)
- This function evaluates its argument, and it returns the result. Thus, it
is a no-operation. However, a side-effect of the function is that
information about the evaluation is logged to the evaluating program's log
file, at the D_FULLDEBUG debug level. This is useful for
determining why a given ClassAd expression is evaluating the way it does.
For example, if a condor_startd START expression is
unexpectedly evaluating to UNDEFINED, then wrapping the expression
in this debug() function will log information about each component of the
expression to the log file, making it easier to understand the
expression.
- String envV1ToV2(String old_env)
- This function converts a set of environment variables from the old
HTCondor syntax to the new syntax. The single argument should evaluate to
a string that represents a set of environment variables using the old
HTCondor syntax (usually stored in the job ClassAd attribute Env).
The result is the same set of environment variables using the new HTCondor
syntax (usually stored in the job ClassAd attribute Environment).
If the argument evaluates to UNDEFINED, then the result is also
UNDEFINED.
- String mergeEnvironment(String env1 [ , String env2, ...
])
- This function merges multiple sets of environment variables into a single
set. If multiple arguments include the same variable, the one that appears
last in the argument list is used. Each argument should evaluate to a
string which represents a set of environment variables using the new
HTCondor syntax or UNDEFINED, which is treated like an empty
string. The result is a string that represents the merged set of
environment variables using the new HTCondor syntax (suitable for use as
the value of the job ClassAd attribute Environment).
For the following functions, a delimiter is represented by a
string. Each character within the delimiter string delimits individual
strings within a list of strings that is given by a single string. The
default delimiter contains the comma and space characters. A string within
the list is ended (delimited) by one or more characters within the delimiter
string.
- Integer stringListSize(String list [ , String delimiter
])
- Returns the number of elements in the string list, as delimited by
the optional delimiter string. Returns ERROR if either
argument is not a string.
This function returns ERROR if other than 1 or 2
arguments are given.
- Integer stringListSum(String list [ , String delimiter ]) OR
Real stringListSum(String list [ , String delimiter ])
- Sums and returns the sum of all items in the string list, as
delimited by the optional delimiter string. If all items in the
list are integers, the return value is also an integer. If any item in the
list is a real value (noninteger), the return value is a real. If any item
does not represent an integer or real value, the return value is
ERROR.
- Real stringListAvg(String list [ , String delimiter ])
- Sums and returns the real-valued average of all items in the string
list, as delimited by the optional delimiter string. If any
item does not represent an integer or real value, the return value is
ERROR. A list with 0 items (the empty list) returns the value
0.0.
- Integer stringListMin(String list [ , String delimiter ]) OR
Real stringListMin(String list [ , String delimiter ])
- Finds and returns the minimum value from all items in the string
list, as delimited by the optional delimiter string. If all
items in the list are integers, the return value is also an integer. If
any item in the list is a real value (noninteger), the return value is a
real. If any item does not represent an integer or real value, the return
value is ERROR. A list with 0 items (the empty list) returns the
value UNDEFINED.
- Integer stringListMax(String list [ , String delimiter ]) OR
Real stringListMax(String list [ , String delimiter ])
- Finds and returns the maximum value from all items in the string
list, as delimited by the optional delimiter string. If all
items in the list are integers, the return value is also an integer. If
any item in the list is a real value (noninteger), the return value is a
real. If any item does not represent an integer or real value, the return
value is ERROR. A list with 0 items (the empty list) returns the
value UNDEFINED.
- Integer stringListsIntersect(String list1, String list2 [ , String
delimiter ])
- Returns TRUE if the lists contain any matching elements, and
returns FALSE if the lists do not contain any matching elements.
Returns ERROR if either argument is not a string or if an incorrect
number of arguments are given.
- Boolean
stringListSubsetMatch(String list1, String list2 [ , String delimiter
])
- Returns TRUE if all item in the string list1 are also in the
string list2, as delimited by the optional delimiter string.
Returns FALSE if list1 has any items that are not in
list2. Both lists are treated as sets. Empty items and duplicate
items are ignored. The return value is TRUE if list1 is
UNDEFINED or empty and list2 is any string value. The return
value is FALSE if list1 is any string vlaue and list2
is UNDEFINED. The return value is UNDEFINED if both
list1 and list2 are UNDEFINED. The return value is
ERROR, if any of the arguments are not either strings or
UNDEFINED
The following six functions utilize regular expressions as defined
and supported by the PCRE library. See http://www.pcre.org for
complete documentation of regular expressions.
The options argument to these functions is a string of
special characters that modify the use of the regular expressions. Inclusion
of characters other than these as options are ignored.
- I or i
- Ignore letter case.
- M or m
- Modifies the interpretation of the caret (^) and dollar sign ($)
characters. The caret character matches the start of a string, as well as
after each newline character. The dollar sign character matches before a
newline character.
- S or s
- The period matches any character, including the newline character.
- F or f
- When doing substitution, return the full target string with substitutions
applied. Normally, only the substitute text is returned.
- G or g
- When doing substitution, apply the substitution for every matching portion
of the target string (that doesn't overlap a previous match).
- Boolean
regexp(String pattern, String target [ , String options ])
- Uses the regular expression given by string pattern to scan through
the string target. Returns TRUE when target matches
the regular expression given by pattern. Returns FALSE
otherwise. If any argument is not a string, or if pattern does not
describe a valid regular expression, returns ERROR.
- Boolean
regexpMember(String pattern, List targetStrings [ , String options
])
- Uses the description of a regular expression given by string
pattern to scan through a List of string n targetStrings.
Returns TRUE when target matches a regular expression given
by pattern. If no strings match, and at least one item in
targetString evaluated to undefined, returns undefined. If any item in
targetString before a match evaluated to neither a string nor undefined,
returns ERROR.
- String regexps
- (String pattern, String target, String substitute [ , String options
]) Uses the regular expression given by string pattern to scan
through the string target. When target matches the regular
expression given by pattern, the string substitute is
returned, with backslash expansion performed. If any argument is not a
string, returns ERROR.
- String replace
- (String pattern, String target, String substitute [ , String options
]) Uses the regular expression given by string pattern to scan
through the string target. Returns a modified version of
target, where the first substring that matches pattern is
replaced by the string substitute, with backslash expansion
performed. Equivalent to regexps() with the f option. If any
argument is not a string, returns ERROR.
- String replaceall
- (String pattern, String target, String substitute [ , String options
]) Uses the regular expression given by string pattern to scan
through the string target. Returns a modified version of
target, where every substring that matches pattern is
replaced by the string substitute, with backslash expansion
performed. Equivalent to regexps() with the fg options. If
any argument is not a string, returns ERROR.
- Boolean
stringList_regexpMember
- (String pattern, String list [ , String delimiter ] [ , String options
]) Uses the description of a regular expression given by string
pattern to scan through the list of strings in list. Returns
TRUE when one of the strings in list is a regular expression
as described by pattern. The optional delimiter describes
how the list is delimited, and string options modifies how the
match is performed. Returns FALSE if pattern does not match
any entries in list. The return value is ERROR, if any of
the arguments are not strings, or if pattern is not a valid regular
expression.
- String userHome(String userName [ , String default ])
- Returns the home directory of the given user as configured on the current
system (determined using the getpwdnam() call). (Returns default if
the default argument is passed and the home directory of the user
is not defined.)
- List userMap(String
mapSetName, String userName)
- Map an input string using the given mapping set. Returns a string
containing the list of groups to which the user belongs separated by
commas or undefined if the user was not found in the map file.
- String userMap(String mapSetName, String userName, String
preferredGroup)
- Map an input string using the given mapping set. Returns a string, which
is the preferred group if the user is in that group; otherwise it is the
first group to which the user belongs, or undefined if the user belongs to
no groups.
- String userMap(String mapSetName, String userName, String
preferredGroup, String defaultGroup)
- Map an input string using the given mapping set. Returns a string, which
is the preferred group if the user is in that group; the first group to
which the user belongs, if any; and the default group if the user belongs
to no groups.
The maps for the userMap() function are defined by the
following configuration macros:
<SUBSYS>_CLASSAD_USER_MAP_NAMES,
CLASSAD_USER_MAPFILE_<name> and
CLASSAD_USER_MAPDATA_<name> (see the
admin-manual/configuration-macros:htcondor-wide configuration file
entries section).
The ClassAd mechanism's primary purpose is for matching entities
that supply constraints on candidate matches. The mechanism is therefore
defined to carry out expression evaluations in the context of two ClassAds
that are testing each other for a potential match. For example, the
condor_negotiator evaluates the Requirements expressions of
machine and job ClassAds to test if they can be matched. The semantics of
evaluating such constraints is defined below.
Literals are self-evaluating, Thus, integer, string, real,
undefined and error values evaluate to themselves.
Since the expression evaluation is being carried out in the
context of two ClassAds, there is a potential for name space ambiguities.
The following rules define the semantics of attribute references made by
ClassAd A that is being evaluated in a context with another ClassAd B:
- 1.
- If the reference is prefixed by a scope resolution prefix,
- If the prefix is MY., the attribute is looked up in ClassAd A. If
the named attribute does not exist in A, the value of the reference is
UNDEFINED. Otherwise, the value of the reference is the value of
the expression bound to the attribute name.
- Similarly, if the prefix is TARGET., the attribute is looked up in
ClassAd B. If the named attribute does not exist in B, the value of the
reference is UNDEFINED. Otherwise, the value of the reference is
the value of the expression bound to the attribute name.
- 2.
- If the reference is not prefixed by a scope resolution prefix,
- If the attribute is defined in A, the value of the reference is the value
of the expression bound to the attribute name in A.
- Otherwise, if the attribute is defined in B, the value of the reference is
the value of the expression bound to the attribute name in B.
- Otherwise, if the attribute is defined in the ClassAd environment, the
value from the environment is returned. This is a special environment, to
be distinguished from the Unix environment. Currently, the only attribute
of the environment is CurrentTime, which evaluates to the integer
value returned by the system call time(2).
- Otherwise, the value of the reference is UNDEFINED.
- 3.
- Finally, if the reference refers to an expression that is itself in the
process of being evaluated, there is a circular dependency in the
evaluation. The value of the reference is ERROR.
All operators in the ClassAd language are total, and thus have
well defined behavior regardless of the supplied operands. Furthermore, most
operators are strict with respect to ERROR and UNDEFINED, and
thus evaluate to ERROR or UNDEFINED if either of their
operands have these exceptional values.
- •
- Arithmetic operators:
- 1.
- The operators \*, /, + and - operate
arithmetically only on integers and reals.
- 2.
- Arithmetic is carried out in the same type as both operands, and type
promotions from integers to reals are performed if one operand is an
integer and the other real.
- 3.
- The operators are strict with respect to both UNDEFINED and
ERROR.
- 4.
- If either operand is not a numerical type, the value of the operation is
ERROR.
- •
- Comparison operators:
- 1.
- The comparison operators ==, !=, <=, <,
>= and > operate on integers, reals and strings.
- 2.
- String comparisons are case insensitive for most operators. The only
exceptions are the operators =?= and =!=, which do case
sensitive comparisons assuming both sides are strings.
- 3.
- Comparisons are carried out in the same type as both operands, and type
promotions from integers to reals are performed if one operand is a real,
and the other an integer. Strings may not be converted to any other type,
so comparing a string and an integer or a string and a real results in
ERROR.
- 4.
- The operators ==, !=, <=, <,
>=, and > are strict with respect to both
UNDEFINED and ERROR.
- 5.
- In addition, the operators =?=, is, =!=, and
isnt behave similar to == and !=, but are not strict.
Semantically, the =?= and is test if their operands are
"identical," i.e., have the same type and the same value. For
example, 10 == UNDEFINED and UNDEFINED == UNDEFINED both
evaluate to UNDEFINED, but 10 =?= UNDEFINED and
UNDEFINED is UNDEFINED evaluate to FALSE and
TRUE respectively. The =!= and isnt operators test
for the "is not identical to" condition.
=?= and is have the same behavior as each other.
And isnt and =!= behave the same as each other. The
ClassAd unparser will always use =?= in preference to is
and =!= in preference to isnt when printing out
ClassAds.
- •
- Logical operators:
- 1.
- The logical operators && and || operate on integers
and reals. The zero value of these types are considered FALSE and
non-zero values TRUE.
- 2.
- The operators are not strict, and exploit the "don't care"
properties of the operators to squash UNDEFINED and ERROR
values when possible. For example, UNDEFINED && FALSE evaluates to
FALSE, but UNDEFINED || FALSE evaluates to
UNDEFINED.
- 3.
- Any string operand is equivalent to an ERROR operand for a logical
operator. In other words, TRUE && "foobar"
evaluates to ERROR.
- •
- The Ternary operator:
- 1.
- The Ternary operator (expr1 ? expr2 : expr3) operate with
expressions. If all three expressions are given, the operation is
strict.
- 2.
- However, if the middle expression is missing, eg. expr1 ?:
expr3, then, when expr1 is defined, that defined value is returned.
Otherwise, when expr1 evaluated to UNDEFINED, the value of expr3 is
evaluated and returned. This can be a convenient shortcut for writing what
would otherwise be a much longer classad expression.
The =?= operator is similar to the == operator. It
checks if the left hand side operand is identical in both type and value to
the the right hand side operand, returning TRUE when they are
identical.
CAUTION:
For strings, the comparison is case-insensitive with the
== operator and case-sensitive with the =?= operator. A key
point in understanding is that the =?= operator only produces
evaluation results of TRUE and FALSE, where the ==
operator may produce evaluation results TRUE, FALSE,
UNDEFINED, or ERROR.
Table 4.1 presents examples that define the outcome of the
== operator. Table 4.2 presents examples that define the outcome of
the =?= operator.
expression |
evaluated result |
(10 == 10) |
TRUE |
(10 == 5) |
FALSE |
(10 == "ABC") |
ERROR |
"ABC" ==
"abc" |
TRUE |
(10 == UNDEFINED) |
UNDEFINED |
(UNDEFINED == UNDEFINED) |
UNDEFINED |
Table 4.1: Evaluation examples for the == operator
expression |
evaluated result |
(10 =?= 10) |
TRUE |
(10 =?= 5) |
FALSE |
(10 =?= "ABC") |
FALSE |
"ABC" =?=
"abc" |
FALSE |
(10 =?= UNDEFINED) |
FALSE |
(UNDEFINED =?= UNDEFINED) |
TRUE |
Table 4.2: Evaluation examples for the =?= operator
The =!= operator is similar to the != operator. It
checks if the left hand side operand is not identical in both type and value
to the the right hand side operand, returning FALSE when they are
identical.
CAUTION:
For strings, the comparison is case-insensitive with the
!= operator and case-sensitive with the =!= operator. A key point in
understanding is that the =!= operator only produces evaluation results
of TRUE and FALSE, where the != operator may produce
evaluation results TRUE, FALSE, UNDEFINED, or
ERROR.
Table 4.3 presents examples that define the outcome of the
!= operator. Table 4.4 presents examples that define the outcome of
the =!= operator.
expression |
evaluated result |
(10 != 10) |
FALSE |
(10 != 5) |
TRUE |
(10 != "ABC") |
ERROR |
"ABC" !=
"abc" |
FALSE |
(10 != UNDEFINED) |
UNDEFINED |
(UNDEFINED != UNDEFINED) |
UNDEFINED |
Table 4.3: Evaluation examples for the != operator
expression |
evaluated result |
(10 =!= 10) |
FALSE |
(10 =!= 5) |
TRUE |
(10 =!= "ABC") |
TRUE |
"ABC" =!=
"abc" |
TRUE |
(10 =!= UNDEFINED) |
TRUE |
(UNDEFINED =!= UNDEFINED) |
FALSE |
Table 4.4: Evaluation examples for the =!= operator
The simplicity and flexibility of ClassAds is heavily exploited in
the HTCondor system. ClassAds are not only used to represent machines and
jobs in the HTCondor pool, but also other entities that exist in the pool
such as submitters of jobs and master daemons. Since arbitrary expressions
may be supplied and evaluated over these ClassAds, users have a uniform and
powerful mechanism to specify constraints over these ClassAds. These
constraints can take the form of Requirements expressions in resource
and job ClassAds, or queries over other ClassAds.
The requirements and rank expressions within the
submit description file are the mechanism by which users specify the
constraints and preferences of jobs. For machines, the configuration
determines both constraints and preferences of the machines.
For both machine and job, the rank expression specifies the
desirability of the match (where higher numbers mean better matches). For
example, a job ClassAd may contain the following expressions:
Requirements = (Arch == "INTEL") && (OpSys == "LINUX")
Rank = TARGET.Memory + TARGET.Mips
In this case, the job requires a 32-bit Intel processor running a
Linux operating system. Among all such computers, the customer prefers those
with large physical memories and high MIPS ratings. Since the Rank is
a user-specified metric, any expression may be used to specify the perceived
desirability of the match. The condor_negotiator daemon runs
algorithms to deliver the best resource (as defined by the rank
expression), while satisfying other required criteria.
Similarly, the machine may place constraints and preferences on
the jobs that it will run by setting the machine's configuration. For
example,
Friend = Owner == "tannenba" || Owner == "wright"
ResearchGroup = Owner == "jbasney" || Owner == "raman"
Trusted = Owner != "rival" && Owner != "riffraff"
START = Trusted && ( ResearchGroup || LoadAvg < 0.3 && KeyboardIdle > 15*60 )
RANK = Friend + ResearchGroup*10
The above policy states that the computer will never run jobs
owned by users rival and riffraff, while the computer will always run a job
submitted by members of the research group. Furthermore, jobs submitted by
friends are preferred to other foreign jobs, and jobs submitted by the
research group are preferred to jobs submitted by friends.
Note: Because of the dynamic nature of ClassAd expressions,
there is no a priori notion of an integer-valued expression, a real-valued
expression, etc. However, it is intuitive to think of the
Requirements and Rank expressions as integer-valued and
real-valued expressions, respectively. If the actual type of the expression
is not of the expected type, the value is assumed to be zero.
The flexibility of this system may also be used when querying
ClassAds through the condor_status and condor_q tools which
allow users to supply ClassAd constraint expressions from the command
line.
Needed syntax is different on Unix and Windows platforms, due to
the interpretation of characters in forming command-line arguments. The
expression must be a single command-line argument, and the resulting
examples differ for the platforms. For Unix shells, single quote marks are
used to delimit a single argument. For a Windows command window, double
quote marks are used to delimit a single argument. Within the argument, Unix
escapes the double quote mark by prepending a backslash to the double quote
mark. Windows escapes the double quote mark by prepending another double
quote mark. There may not be spaces in between.
Here are several examples. To find all computers which have had
their keyboards idle for more than 60 minutes and have more than 4000 MB of
memory, the desired ClassAd expression is
KeyboardIdle > 60*60 && Memory > 4000
On a Unix platform, the command appears as
$ condor_status -const 'KeyboardIdle > 60*60 && Memory > 4000'
Name OpSys Arch State Activity LoadAv Mem ActvtyTime
100
slot1@altair.cs.wi LINUX X86_64 Owner Idle 0.000 8018 13+00:31:46
slot2@altair.cs.wi LINUX X86_64 Owner Idle 0.000 8018 13+00:31:47
...
...
slot1@athena.stat. LINUX X86_64 Unclaimed Idle 0.000 7946 0+00:25:04
slot2@athena.stat. LINUX X86_64 Unclaimed Idle 0.000 7946 0+00:25:05
...
...
The Windows equivalent command is
> condor_status -const "KeyboardIdle > 60*60 && Memory > 4000"
Here is an example for a Unix platform that utilizes a regular
expression ClassAd function to list specific information. A file contains
ClassAd information. condor_advertise is used to inject this
information, and condor_status constrains the search with an
expression that contains a ClassAd function.
$ cat ad
MyType = "Generic"
FauxType = "DBMS"
Name = "random-test"
Machine = "f05.cs.wisc.edu"
MyAddress = "<128.105.149.105:34000>"
DaemonStartTime = 1153192799
UpdateSequenceNumber = 1
$ condor_advertise UPDATE_AD_GENERIC ad
$ condor_status -any -constraint 'FauxType=="DBMS" && regexp("random.*", Name, "i")'
MyType TargetType Name
Generic None random-test
The ClassAd expression describing a machine that advertises a
Windows operating system:
Here are three equivalent ways on a Unix platform to list all
machines advertising a Windows operating system. Spaces appear in these
examples to show where they are permitted.
$ condor_status -constraint ' OpSys == "WINDOWS" '
$ condor_status -constraint OpSys==\"WINDOWS\"
$ condor_status -constraint "OpSys==\"WINDOWS\""
The equivalent command on a Windows platform to list all machines
advertising a Windows operating system must delimit the single argument with
double quote marks, and then escape the needed double quote marks that
identify the string within the expression. Spaces appear in this example
where they are permitted.
> condor_status -constraint " OpSys == ""WINDOWS"" "
The ClassAd language provides a rich set of functions. It is
possible to add new functions to the ClassAd language without recompiling
the HTCondor system or the ClassAd library. This requires implementing the
new function in the C++ programming language, compiling the code into a
shared library, and telling HTCondor where in the file system the shared
library lives.
While the details of the ClassAd implementation are beyond the
scope of this document, the ClassAd source distribution ships with an
example source file that extends ClassAds by adding two new functions, named
todays_date() and double(). This can be used as a model for users to
implement their own functions. To deploy this example extension, follow the
following steps on Linux:
- Download the ClassAd source distribution from
http://www.cs.wisc.edu/condor/classad.
- Unpack the tarball.
- Inspect the source file shared.cpp. This one file contains the
whole extension.
- Build shared.cpp into a shared library. On Linux, the command line
to do so is
$ g++ -DWANT_CLASSAD_NAMESPACE -I. -shared -o shared.so \
-Wl,-soname,shared.so -o shared.so -fPIC shared.cpp
- •
- Copy the file shared.so to a location that all of the HTCondor
tools and daemons can read.
$ cp shared.so `condor_config_val LIBEXEC`
- •
- Tell HTCondor to load the shared library into all tools and daemons, by
setting the CLASSAD_USER_LIBS configuration variable to the full
name of the shared library. In this case,
CLASSAD_USER_LIBS = $(LIBEXEC)/shared.so
- Restart HTCondor.
- Test the new functions by running
$ condor_status -format "%s\n" todays_date()
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Department, University of Wisconsin-Madison, Madison, WI, US. Licensed under
the Apache License, Version 2.0.