since - display content of a file since the last time

since [-hnqvx] files

since is similar to tail since it also displays the tail of a file. However since displays only the data which has been added since the last time since was run. If since has not been run before the entire file is displayed. since is useful for watching over log files.

since /var/log/apache/{access,error}_log > /dev/null

lynx --dump http://localhost/ > /dev/null

since /var/log/apache/{access,error}_log

-h

Print a terse help message.

-n

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

-q

Decrease the verbosity of the output.

-v

Increase the verbosity of the output.

-x

Exclude files with compressed extensions.

.since File recording the length of the files displayed previously. The location of the file can be set by using the SINCE environment variable, for example export SINCE= /var/log/sincefile will tell since to use the file /var/log/sincefile. If the SINCE environment variable has not been set since will use the HOME environment variable and store the information in the file .since in the directory pointed to by the variable. If neither the SINCE nor the HOME variable are set since will use the file /tmp/since.

since will break when used across NFS on architectures which have different st_* field sizes. since uses the inode of a file as its key, if that inode is recycled since might get confused. since is not particularly efficient when storing the stat() information, but should work reasonably well unless you plan to look at thousands of files. Functionality equivalent to since can probably be achieved with a number of trivial shell scripts.

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

tail(1), stat(2).