---
name: "since"
section: "1"
platform: "linux"
package: "since"
version: "1.1-7"
release: "Debian 13 (Trixie)"
platforms: ["linux"]
url: "https://new.carta.tech/since"
---

# since(1)

display content of a file since the last time

## 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)](/rename/2.md) instead of updating 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 interrupted.

- \-h

  Print a terse help message.

- \-l

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

- \-m

  Disable  [**mmap**(2)](/mmap/2.md), use  [**read**(2)](/read/2.md) instead to access state and data files.  Note that for certain smaller io operations [**read**(2)](/read/2.md) 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 initial 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)](/getpwuid/3.md) 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)](/stat/2.md) 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)](/tail/1.md), [**stat**(2)](/stat/2.md).