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| -rw-r--r-- | ChangeLog | 4 | ||||
| -rw-r--r-- | txr.1 | 57 |
2 files changed, 61 insertions, 0 deletions
@@ -1,5 +1,9 @@ 2013-11-28 Kaz Kylheku <kaz@kylheku.com> + * txr.1: Documented open-tail and make-time. + +2013-11-28 Kaz Kylheku <kaz@kylheku.com> + Extending intrinsic functions to go up to 7 arguments. Adding wrapper for mktime. @@ -10355,6 +10355,38 @@ or output stream. Note that the "b" mode is not supported. Whether a stream is text or binary depends on which operations are invoked on it. +.SS Function open-tail + +.TP +Syntax: + + (open-tail <path> <mode-string> <seek-to-end-p>) + +.TP +Description: + +The open-tail function creates a tail stream connected to the file which is +located at the given <path>. The <mode-string> argument is a string which uses +the same conventions as the mode argument of the C language fopen function. +The mode string determines whether the stream is an input stream +or output stream. Note that the "b" mode is not supported. +Whether a stream is text or binary depends on which operations +are invoked on it. The <seek-to-end-p> argument is a boolean whcih +determines whether the initial read/write position is at the +start of the file, or just past the end. + +A tail stream has special semantics with regard to reading at the end +of file. A tail stream never reports an end-of-file condition; instead +it polls the file until more data is added. Furthermore, if the file +is truncated, or replaced with a smaller file, the tail stream follows +this change: it automatically opens the smaller file and starts reading from +the beginning (the <seek-to-end-p> flag only applies to the initial open). +In this manner, a tail stream can dynamically growing rotating log files. + +Caveat: since a tail stream can re-open a new file which has the same +name as the original file, it will do the wrong thing if the program +changes the current working directory, and the path name is relative. + .SH COPROCESSES .SS Functions open-command, open-process @@ -10743,6 +10775,31 @@ the format string of the C library function strftime. The <time> argument is an integer representing seconds obtained from the time function or from the time-usec function. +.SS Function make-time + +.TP +Syntax: + + (make-time <year> <month> <day> <hour> <minute> <second> <dst-advice>) + +.TP +Description + +The make-time function returns a time value, similar to the one returned by the +time function. The time value is constructed not from the system clock, but +from a date and time specified as arguments. The <year> argument is a +calendar year, like 2013. The <month> argument ranges from 1 through 12. +These arguments represent a local time, in the current time zone. + +The <dst-advice> argument specifies whether the time is expressed in +daylight savings time (DST). It takes on these values: nil, the keyword :auto, +or any other value which denotes boolean true. + +If <dst-advice> is t, then the time is assumed to be expressed in DST. +If the argument is nil, then the time is assumed not to be in DST. +If <dst-advice> is :auto, then the function tries to determine whether +DST is in effect in the current time zone for the specified date and time. + .SH WEB PROGRAMMING SUPPORT .SS Functions url-encode and url-decode |