module Linebuf: Linebuf
type
t
The type of a line buffer.
type
error_type =
| |
Null_retry |
| |
Too_many_nulls |
| |
Exception of string * exn |
type
lnum =
type
result =
| |
Success of lnum * string |
| |
Nothing_available |
| |
Error of error_type |
| |
Fatal_error of string * exn |
exception File_truncated_or_deleted
val create : ?pos:Int64.t ->
?close_on_eof:bool ->
?null_hack:[ `Off | `Retry | `Retry_then_fail ] ->
?eprint_nulls:bool ->
?follow_deletes:bool ->
?signal_on_truncate_or_delete:bool -> string -> t
Open a line buffer from the passed filename. If close_on_eof
is
set, when eof
is read, the file will be closed and reopened if
necessary. if follow_deletes
is set, then when eof
is read linebuf
will stat the file, and if it has been deleted and recreated it
will open the new file. If eprint_nulls
is set, then when nulls are found,
a warning message will be printed to stderr. null_hack
specifies the
behaviour of the linebuf upon reception of null characters in the file (as
seen when tailing files over CIFS).
Null hack options:
`Off: don't check for nulls, just keep going.
`Retry: close and reopen file when nulls are read from the file.
If max_null_retries is reached, then pass the line with nulls.
`Retry_then_fail: the same as retry, except that an exception is raised
once max_null_retries is reached.
val close : t -> unit
Closes the line buffer (and the underlying file).
val is_closed : t -> bool
Returns whether or not the line buffer is closed
val try_read : t -> string option
Tries to read a line from the file. If no more lines are available,
returns None
.
val try_read_lnum : t -> (lnum * string) option
try_read_lnum
is like try_read
except also provides the line number of the
read line.
val try_read_lnum_verbose : t -> result
Like try_read, except that it returns more verbose errors
val read : t -> string
Calls try_read every 0.01 seconds and returns when a line is available.
val tail : t -> unit
Seeks to the end of the file and blocks until another line is available -- this new
line is not returned. Successive return values of try_read_lnum
and
try_read_lnum
will return Unknown
as the current line number until
reset
is called
val unsafe_tail : t -> unit
Same as
tail
except it may return before a new line is available on the file
i.e. it (usually) doesn't block. Note that this does interact with files in
a fairly naive way, so there's no guarantee that it absolutely doesn't block.
Note that when this functions is called, the next line that's read may be a partial
line. After that first line, only full lines will be read.
val name : t -> string
val reset : t -> unit
reopens the file and seeks to the beginning. Also recovers the ability to get line
numbers if tail
has been called