Ubuntu Manpage: cronolog - write log messages to log files named according to a template

NAME

       cronolog - write log messages to log files named according to a template

SYNOPSIS

       cronolog [OPTION]... template

DESCRIPTION

       cronolog  is  a simple program that reads log messages from its input and writes them to a
       set of output files, the names of which are constructed using  template  and  the  current
       date  and  time.  The template uses the same format specifiers as the Unix date(1) command
       (which are the same as the standard C strftime library function).

       Before writing a message cronolog checks the time to see whether the current log  file  is
       still  valid and if not it closes the current file, expands the template using the current
       date and time to  generate  a  new  file  name,  opens  the  new  file  (creating  missing
       directories  on the path of the new log file as needed unless the program is compiled with
       -DDONT_CREATE_SUBDIRS) and calculates the time at which the new file will become invalid.

       cronolog is intended to be used in conjunction with a Web server, such as Apache to  split
       the  access  log  into  daily  or  monthly  logs.   For  example  the Apache configuration
       directives:

               TransferLog "|/usr/bin/cronolog /www/logs/%Y/%m/%d/access.log"
               ErrorLog    "|/usr/bin/cronolog /www/logs/%Y/%m/%d/errors.log"

       would instruct Apache to pipe its access and error log messages into  separate  copies  of
       cronolog, which would create new log files each day in a directory hierarchy structured by
       date, i.e. on 31 December 1996 messages would be written to

               /www/logs/1996/12/31/access.log
               /www/logs/1996/12/31/errors.log

       after midnight the files

               /www/logs/1997/01/01/access.log
               /www/logs/1997/01/01/errors.log

       would be used, with the directories 1997, 1997/01 and 1997/01/01 being created if they did
       not  already  exist.  (Note that prior to version 1.2 Apache did not allow a program to be
       specified as the argument of the ErrorLog directive.)

Options

cronolog accepts the following options and arguments:

-H NAME

--hardlink=NAME
maintain a hard link from NAME to the current log file.

-S NAME

--symlink=NAME

-l NAME

--link=NAME
maintain a symbolic link from NAME to the current log file.

-P NAME

--prev-simlink=NAME
maintain a symbolic link from NAME to the previous log file. Requires that the
--symlink option is specified, as cronolog renames the current link to the name
specified for the previous link.

-h

--help print a help message and then exit.

-p PERIOD

--period=PERIOD
specifies the period explicitly as an optional digit string followed by one of
units: seconds, minutes, hours, days, weeks or months. The count cannot be greater
than the number of units in the next larger unit, i.e. you cannot specify "120
minutes", and for seconds, minutes and hours the count must be a factor of the next
higher unit, i.e you can specify 1, 2, 3, 4, 5, 6, 10, 15, 20 or 30 minutes but not
say 7 minutes.

-d PERIOD

--delay=PERIOD
specifies the delay from the start of the period before the log file is rolled
over. For example specifying (explicitly or implicitly) a period of 15 minutes and
a delay of 5 minutes results in the log files being rotated at five past, twenty
past, twentyfive to and ten to each hour. The delay cannot be longer than the
period.

-o

--once-only
create single output log from template, which is not rotated.

-x FILE

--debug=FILE
write debug messages to FILE or to the standard error stream if FILE is "-". (See
the README file for more details.)

-s TIME

--start-time=TIME
pretend that the starting time is TIME (for debugging purposes). TIME should be
something like DD MONTH YYYY HH:MM:SS (the day and month are reversed if the
american option is specified). If the seconds are omitted then they are taken as
zero and if the hours and minutes are omitted then the time of day is taken as
00:00:00 (i.e. midnight). The day, month and year can be separated by spaces,
hyphens (-) or solidi (/).

-a

--american
Interprete the date part of the starting time the American way (month then day).

-e

--european
Interprete the date part of the starting time the European way (day then month).
This is the default.

-v

--version
print version information and exit.

Template format

       Each character in the template represents a character in the expanded filename, except for
       date and time format specifiers, which are replaced by their expansion.  Format specifiers
       consist of a `%' followed by one of the following characters:

       %      a literal % character

       n      a new-line character

       t      a horizontal tab character

       Time fields:

       H      hour (00..23)

       I      hour (01..12)

       p      the locale's AM or PM indicator

       M      minute (00..59)

       S      second (00..61, which allows for leap seconds)

       X      the locale's time representation (e.g.: "15:12:47")

       Z      time zone (e.g. GMT), or nothing if the time zone cannot be determined

       Date fields:

       a      the locale's abbreviated weekday name (e.g.: Sun..Sat)

       A      the locale's full weekday name (e.g.: Sunday .. Saturday)

       b      the locale's abbreviated month name (e.g.: Jan .. Dec)

       B      the locale's full month name, (e.g.: January .. December)

       c      the locale's date and time (e.g.: "Sun Dec 15 14:12:47 GMT 1996")

       d      day of month (01 .. 31)

       j      day of year (001 .. 366)

       m      month (01 .. 12)

       U      week of the year with Sunday as first day of week (00..53, where week 1 is the week
              containing the first Sunday of the year)

       W      week of the year with Monday as first day of week (00..53, where week 1 is the week
              containing the first Monday of the year)

       w      day of week (0 .. 6, where 0 corresponds to Sunday)

       x      locale's date representation (e.g. today in April in Britain: "13/04/97")

       y      year without the century (00 .. 99)

       Y      year with the century (1970 .. 2038)

       Other specifiers may be available depending on  the  C  library's  implementation  of  the
       strftime function.

FUTURE DIRECTIONS

       The functionality of cronolog could be built into Apache,  thus  saving  the  overhead  of
       having  a  process per log stream and that of transferring data from the server process to
       the cronolog process.  The main complication is  handling  the  case  where  multiple  log
       streams  are  written  to  the  same  file (template), for example where different virtual
       servers write to the same set of log files.

AUTHOR

       Andrew Ford <A.Ford@ford-mason.co.uk>

       cronolog is based on a program called rotatelogs by Ben Laurie, which is packaged with the
       Apache web server.

       The symbolic link option was suggested by Juergen Lesny.

                                            March 1998                               cronolog(1m)