table of contents
sys(3) | AFNIX Module | sys(3) |
NAME¶
sys - standard system access moduleSTANDARD SYSTEM ACCESS MODULE¶
The Standard System Access module is an original implementation of various objects designed to provide a specialized access to the underlying system. Most of the system accesses are provided in the form of functions which have been designed to be portable as possible. One example of this, are the time and date management objects. Interpreter informationzsh> axi 0501.als program name : afnix operating system name : linux operating system type : unix afnix official uri : http://www.afnix.orgInterpreter version
println "major version number : " interp:major-version println "minor version number : " interp:minor-version println "patch version number : " interp:patch-versionOperating system
println "operating system name : " interp:os-name println "operating system type : " interp:os-typeProgram information
println "program name : " interp:program-name println "afnix official uri : " interp:afnix-uriSystem services
Function | Description |
exit | terminate with an exit code |
sleep | pause for a certain time |
get-pid | get the process identifier |
get-env | get an environment variable |
get-host-name | get the host name |
get-user-name | get the user name |
const time (afnix:sys:Time) assert true (afnxi:sys:time-p time)A simple time representation can also be built by hours, minutes and seconds. In this case, the time is a time definition at day 0 in the reference calendar.
const time (afnix:sys:Time 12 23 54)By default a date instance of the current date is constructed. The current date is computed from the machine time and expressed in a particular calendar. By default, the engine uses a special Gregorian calendar as explained before. The important point here s that the date will show up like the user should expect.
const date (afnix:sys:Date) assert true (afnix:sys:date-p date)A date instance can also be built with an absolute time expressed in seconds or with specific elements. with one argument, the date is expressed in seconds since the origin. Since the internal representation is 64 bits, the date room is quite large. For example, the absolute time to represent Jan 1st 1970 is 62167219200 seconds. This epoch is used to adjust the system time on some UNIX system. Another way to create a specific date is to use the date descriptor by year, month and day. With 6 arguments, the time components can also be given. This makes Date one of the constructor that accept the largest number of arguments.
const date (afnix:sys:Date 1789 7 14 16 0 0) assert true (afnix:sys:date-p date)In the previous example, at 17:00 local time, 16:00Z although the concept of time zone was not formalized, the Bastille surrenders on July 14 1789. This example shows that extreme care should be used when dealing with old dates. Note that a simpler form could have been used to set that date. With 3 argument, the date is set at time 00:00:00Z.
const date (afnix:sys:Date 1789 7 14) assert true (afnix:sys:date-p date)Time and date representation
const time (afnix:sys:Time 12 44 55) println (time:format) # 12:44:55 println (time:to-iso) # 14:44:55 println (time:to-rfc) # 14:44:55 +0200in the first form, the time is represented naturally by hour, minutes and seconds. By default, it is the local time that is given. With a flag set to true, the UTC time is displayed. In the second form, the time is displayed in the ISO-8601 form which is the same as before. In the third form, the time is displayed in the RFC-2822 form. This form is always expressed locally with the timezone difference associated with it. It shall be noted that the ISO-8601 mandate to use the suffix 'Z' for the zulu time. This is the difference when using the true flag with the format and to-iso methods.
println (time:format true) # 12:44:55 println (time:to-iso true) # 12:44:55ZThe date representation also operates with 3 methods, namely format, to-iso and to-rfc. For example, if the time is 12:00 in Paris on July 14th 2000, the date will be displayed like below.
const date (afnix:sys:Date 2000 7 14 12 0 0) # Fri Jul 14 07:00:00 2000 println (date:format) # 2000-07-14T07:00:00 println (date:to-iso) # Fri, 14 Jul 2000 07:00:00 -0500 println (date:to-rfc)The example show the local time. With UTC display, only the first two methods can be used.
const date (afnix:sys:Date 2000 7 14 12 0 0) println (date:format true) # Fri Jul 14 12:00:00 2000 println (date:to-iso true) # 2000-07-14T12:00:00ZOptions parsing
const options ( afnix:sys:Options "axi [options] [file [arguments]]")Eventually, the set-user-message method can be used to set the user message. Options definition
options:add-unique-option 'h' "print this help message" options:add-unique-option 'v' "print system version" options:add-vector-option 'i' "add a resolver path" options:add-string-option 'e' "force the encoding mode" options:add-list-option 'f' "assert" "enable assertion checks" options:add-list-option 'f' "nopath" "do not set initial path"The above example shows the option descriptors for the interpreter. Since i is a vector option, multiple occurrences of that option is allowed. It shall be noted that the list option f assert is a debug option. This means that this option is always set when the program is compiled in debug mode. Options parsing and retrieval
options:parse (Vector "-h") if (options:get-unique-option 'h') { options:usage afnix:sys:exit 0 }In the above example, the option vector is parsed with the parse method. The get-unique-option method returns true for the h thus triggering the display of the usage message.
usage: axi [options] [file [arguments]] [h] print this help message [v] print system version [i path] add a resolver path [e mode] force the encoding mode [f assert] enable assertion checks [f nopath] do not set initial pathIf the option is a string option, the get-string-option will return the string associated with that option. It shall be noted that the get-unique-option method can be used to check if the option has been set during the parsing process. If the option is a vector option, the get-vector-option method is more appropriate. In this case, a vector is returned with all strings matching this option.
options:parse ( Vector "-i" "../" "-i" "../.." -e "UTF-08" "hello")In the previous example, the vector option i is set two times. The associated vector option has therefore a length of 2. The string option e is set to UTF-08. For this option e, the get-unique-option method will return true. Finally, the vector argument is filled with one string argument.
STANDARD SYSTEM ACCESS REFERENCE¶
Timetime-p
Inheritance
Object
Constructors
Time (none)
The Time constructor create a time object which is initialized with the current
time.
Time (Integer)
The Time constructor create a time object which is initialized with the time
argument.
Time (Integer Integer Integer)
The Time constructor create a time object which is initialized with the time
specific arguments, which are the hour, the minutes and the seconds.
Methods
add -> none (Integer)
The add method adds the time argument in seconds to the current time value This
method is useful to compute a time in the future, in reference to the current
time.
add-minutes -> none (Integer)
The add-minutes method adds one or several minutes to the current time value.
This method is useful to compute a time in the future, in reference to the
current time.
add-hours -> none (Integer)
The add-hour method adds one or several hours to the current time value. This
method is useful to compute a time in the future, in reference to the current
time.
add-days -> none (Integer)
The add-days method adds one or several days to the current time value. This
method is useful to compute a time in the future, in reference to the current
time.
set-time -> none (Integer)
The set-time method set the absolute time in seconds.
get-time -> Integer (none|Boolean)
The get-time method returns absolute time in seconds. Without argument, the
absolute time is computed in reference to the UTC time. With a boolean
argument set to true, the time is computed in reference to the UTC time. If
the argument is false, the local time is used.
seconds -> Integer (none|Boolean)
The seconds method returns the number of seconds after the minute. Without
argument, the number of seconds is computed in reference to the UTC time. With
a boolean argument set to true, the number of seconds is computed in reference
to the UTC time. If the argument is false, the local time is used. The
returned value is the range 0 to 60.
minutes -> Integer (none|Boolean)
The minutes method returns the number of minutes after the hour. Without
argument, the number of minutes is computed in reference to the UTC time. With
a boolean argument set to true, the number of minutes is computed in reference
to the UTC time. If the argument is false, the local time is used. The
returned value is the range 0 to 60.
hours -> Integer (none|Boolean)
The hours method returns the number of hours since midnight. Without argument,
the number of hours is computed in reference to the local time. With a boolean
argument set to true, the number of hours is computed in reference to the UTC
time. If the argument is false, the local time is used. The returned value is
the range 0 to 23.
format -> String (none|Boolean)
The format method returns a formatted representation of the time in the form of
hh:mm:ss. Without argument, the time is computed in reference to the local
time. With a boolean argument set to true, the time is computed in reference
to the UTC time. If the argument is false, the local time is used.
to-iso -> String (none|Boolean)
The to-iso method returns a formatted representation of the time as specified by
ISO-8601. Without argument, the time is computed in reference to the local
time. With a boolean argument set to true, the time is computed in reference
to the UTC time. If the argument is false, the local time is used.
to-rfc -> String (none|Boolean)
The to-rfc method returns a formatted representation of the time as specified by
RFC-2822. Without argument, the time is computed in reference to the local
time. With a boolean argument set to true, the time is computed in reference
to the UTC time. If the argument is false, the local time is used.
get-base-day -> Integer (none)
The get-base-day method returns the absolute time rounded to the beginning of
the day.
Date
date-p
Inheritance
Time
Constructors
Date (none)
The Date constructor creates a date object which is initialized with the current
time.
date (Integer)
The Date constructor creates a date object which is initialized with the time
argument.
Date (Integer Integer Integer)
The Date constructor creates a date object which is initialized with the date
specific arguments, which are the year, the month and the day in the
month.
Date (Integer Integer Integer Integer Integer
Integer)
The Date constructor creates a date object which is initialized with the date
specific arguments, which are the year, the month, the day in the month, the
hours, the minutes and the seconds.
Methods
year -> Integer (none|Boolean)
The year method returns the date year. the returned value is an absolute year
value which can be negative. Without argument, the number of years is computed
in reference to the local time. With a boolean argument set to true, the
number of years is computed in reference to the UTC time. If the argument is
false, the local time is used.
month -> Integer (none|Boolean)
The month method returns the month in the year. The returned value is the range
1 to 12. Without argument, the number of months is computed in reference to
the local time. With a boolean argument set to true, the number of months is
computed in reference to the UTC time. If the argument is false, the local
time is used.
day -> Integer (none|Boolean)
The day method returns the day in the month. The returned value is the range 1
to 31. Without argument, the number of days is computed in reference to the
local time. With a boolean argument set to true, the number of days is
computed in reference to the UTC time. If the argument is false, the local
time is used.
week-day -> Integer (none|Boolean)
The week-day method returns the day in the week. The returned value is the range
0 to 6 in reference to Sunday. Without argument, the day is computed in
reference to the local time. With a boolean argument set to true, the day is
computed in reference to the UTC time. If the argument is false, the local
time is used.
year-day -> Integer (none|Boolean)
The year-day method returns the day in the year. The returned value is the range
1 to 366 in reference to January 1st. Without argument, the day is computed in
reference to the local time. With a boolean argument set to true, the day is
computed in reference to the UTC time. If the argument is false, the local
time is used.
map-day -> String (none|Boolean)
The map-day method returns a formatted representation of the day. Without
argument, the day is computed in reference to the local time. With a boolean
argument set to true, the day is computed in reference to the UTC time. If the
argument is false, the local time is used.
map-month -> String (none|Boolean)
The map-month method returns a formatted representation of the month. Without
argument, the month is computed in reference to the local time. With a boolean
argument set to true, the month is computed in reference to the UTC time. If
the argument is false, the local time is used.
format -> String (none|Boolean)
The format method returns a formatted representation of the date. Without
argument, the time is computed in reference to the local time. With a boolean
argument set to true, the time is computed in reference to the UTC time. If
the argument is false, the local time is used.
to-iso -> String (none|Boolean)
The to-iso method returns a formatted representation of the date as specified by
ISO-8601. Without argument, the time is computed in reference to the local
time. With a boolean argument set to true, the time is computed in reference
to the UTC time. If the argument is false, the local time is used.
to-web -> String (none)
The to-web method returns a formatted representation of the date as specified by
RFC-1123.
to-rfc -> String (none|Boolean)
The to-rfc method returns a formatted representation of the date as specified by
RFC-2822. Without argument, the time is computed in reference to the local
time. With a boolean argument set to true, the time is computed in reference
to the UTC time. If the argument is false, the local time is used.
to-date -> String (none|Boolean)
The to-date method returns a formatted representation of the date only as
specified by ISO-8601. With this method, the time value is not included in the
representation. Without argument, the date is computed in reference to the
local time. With a boolean argument set to true, the date is computed in
reference to the UTC time. If the argument is false, the local time is
used.
to-time -> String (none|Boolean)
The to-time method returns a formatted representation of the time as returned by
the Time format method. Without argument, the time is computed in reference to
the local time. With a boolean argument set to true, the time is computed in
reference to the UTC time. If the argument is false, the local time is
used.
add-years -> none (Integer)
The add-years method add one or several years to the current date.
add-months -> none (Integer)
The add-months method add one or several months to the current date.
Options
options-p
Inheritance
Object
Constructors
Options (none)
The Options constructor creates a default option object without a user
message.
Options (String)
The Options constructor creates an empty option object with a user message. The
user message is used by the usage method.
Methods
reset -> none (none)
The reset method resets the object data structure but do not remove the option
descriptors. After a reset operation, the class is ready to parse another
string vector.
usage -> none (none)
The usage method prints a usage message with a user message and a one line
description per option. removing all messages.
parse -> Vector (none)
The parse method parse a vector and fill the option data structure. The parse
method is generally called with the interpreter argument vector.
empty-p -> Boolean (none)
The empty- predicate returns true if the argument vector is empty. The argument
vector is filled wit the string that are not options during the parsing
process.
add-list-option -> none (Character String
String)
The add-list-option method creates a new list option. The list option is defined
by the option character and the option string. The first argument is the
option character. The second argument is the option list string. The third
argument is the option message. During the parsing process, the list option
have a string argument which must match one string associated with the option
character.
get-unique-option -> Character String (none)
The add-unique-option method creates a new single option. The option is defined
only by its character. The first argument is the option character. The second
argument is the option message. During the parsing process, a unique option
does not have an argument.
add-string-option -> none (Character String)
The add-string-option method creates a new string option. The option is defined
only by its character. The first argument is the option character. The second
argument is the option message. During the parsing process, a string option
have a string argument.
add-vector-option -> Character String (none)
The add-vector-option method creates a new vector option. The option is defined
only by its character. The first argument is the option character. The second
argument is the option message. During the parsing process, a vector option
have a string argument which is accumulated in a vector.
set-user-message -> none (String)
The set-user-message method sets the global option user message. The user
message is used by the usage method.
get-user-message -> String (none)
The get-user-message method returns the global option user message. The user
message is used by the usage method.
get-unique-option -> Boolean (Character)
The get-unique-option method returns the flag associated with an option. If the
option has been detected during the parsing process, the method returns true.
This method works also for string option or list option to indicate if the
string has been set for that option. with a vector option, it is simpler to
get the vector and check for the vector length. The first argument is the
option character to use for testing.
get-string-option -> String (Character)
The get-string-option method returns the string associated with a string option.
In order to make sure that a string option has been properly set during the
parsing process, it is recommended to use the get-unique-option method. The
first argument is the option character to use for the string retrieval.
get-vector-option -> Vector (Character)
The get-vector-option method returns the vector associated with a vector option.
The first argument is the option character to use for the vector
retrieval.
get-vector-arguments -> Vector (none)
The get-vector-arguments method returns the vector arguments built during the
parsing process.
Functions
exit -> none (Integer)
The exit function terminates the executing program with the exit code specified
as the argument.
sleep -> none (Integer)
The sleep function pause the specific thread for a certain time. The time
argument is expressed in milliseconds. This function returns nil.
get-option -> String (Character)
The get-option function returns a formatted string equivalent to the system
option as specified by the character argument.
get-unique-id -> Integer (none)
The get-unique-id function returns an unique integer number. The returned number
is unique across the session.
get-pid -> Integer (none)
The get-pid function returns the process identifier (pid). The returned value is
a positive integer.
get-env -> String (String)
The get-env function returns the environment variable associated with the string
argument. If the environment does not exist an exception is raised.
get-host-name -> String (none)
The get-host-name function returns the host name. The host name can be either a
simple name or a canonical name with its domain, depending on the system
configuration.
get-user-name -> String (none)
The get-user-name function returns the current user name.
2012-03-26 | AFNIX |