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NAME

       since - display content of a file since the last time

SYNOPSIS

       since [-aefhlmnqvxz] [-d seconds] [-s file] files

DESCRIPTION

       since is a utility designed to monitor log files.  since is similar to tail(2) as it also displays information appended to a file.  However
       since only displays the data which has been added since the last time since was run. If since is run on a particular  file  for	the  first
       time, then the entire file is displayed.

EXAMPLE

       since /var/log/apache/{access,error}_log > /dev/null
       lynx --dump http://localhost/ > /dev/null
       since /var/log/apache/{access,error}_log

OPTIONS

       -a     Make updates to the since state files atomic. This option configures since to use a temporary file and a rename(2) instead of updat-
	      ing the state file in situ.

       -d seconds
	      Specify the number of integer seconds to wait between polling files for changes. This option is only relevant  in  conjunction  with
	      the -f option and if the inotify mechanism is not being used.

       -e     Print the header lines to standard error instead of standard output.

       -f     Follow the specified files. This option is analogous to tail -f as the files are also polled for changes until the process is inter-
	      rupted.

       -h     Print a terse help message.

       -l     Relaxed mode. If some data files are inaccessible since will not fail completely.

       -m     Disable mmap(2), use read(2) instead to access state and data files.  Note that for certain smaller io  operations  read(2)  may	be
	      used even if this option has not been given.

       -n     Do not update the .since file which keeps track of file growth.

       -q     Make the utility operate more quietly.

       -s filename
	      Specify the state file explicitly. Using this option will also disable the use of fallback state files.

       -v     Increase the verbosity. This option can be given multiple times.

       -x     Ignore file arguments which have compressed extensions.

       -z     Discard output. Similar to redirecting the output to /dev/null, but faster. If used in conjunction with the -f option, only the ini-
	      tial output will be discarded.

FILES

       .since

	      State file recording the length of the previously displayed files.  The location of the file can be set on the  command  line  using
	      the  -s  option. If this option is not given, since will check the SINCE environment variable for the location of the state file. If
	      the SINCE environment variable has not been set since will use the HOME environment variable and store the information in  the  file
	      $HOME/.since.  If the HOME variable is not set, since will use a getpwuid(3) lookup. If all these fail will use the file /tmp/since.

BUGS

       since  uses  the  inode	of a file as its key, if that inode is recycled since will get confused.  since is not particularly efficient when
       storing or looking up the stat(2) information. Functionality equivalent to since can probably be achieved with a number	of  trivial  shell
       scripts.

COPYING

       since may only be used, distributed and modified in accordance with the terms of the GPL (GNU General Public License) version 3 or newer as
       published by the FSF (Free Software Foundation).

SEE ALSO

       tail(1), stat(2).

Linux								     JULY 1998								  SINCE(1)