since(1) - f34

1SINCE(1)                         User Manuals                         SINCE(1)
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NAME

6       since - display content of a file since the last time
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SYNOPSIS

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

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

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

26       -a     Make  updates  to the since state files atomic. This option con‐
27              figures since to use a temporary file and a rename(2) instead of
28              updating the state file in situ.
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31       -d seconds
32              Specify  the  number  of integer seconds to wait between polling
33              files for changes. This option is only relevant  in  conjunction
34              with  the  -f  option  and if the inotify mechanism is not being
35              used.
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38       -e     Print the header lines to standard  error  instead  of  standard
39              output.
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42       -f     Follow  the specified files. This option is analogous to tail -f
43              as the files are also polled for changes until  the  process  is
44              interrupted.
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47       -h     Print a terse help message.
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50       -l     Relaxed mode. If some data files are inaccessible since will not
51              fail completely.
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54       -m     Disable mmap(2), use read(2) instead to access  state  and  data
55              files.   Note that for certain smaller io operations read(2) may
56              be used even if this option has not been given.
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59       -n     Do not update the .since file which keeps track of file growth.
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62       -q     Make the utility operate more quietly.
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65       -s filename
66              Specify the state file explicitly. Using this option  will  also
67              disable the use of fallback state files.
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70       -v     Increase the verbosity. This option can be given multiple times.
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73       -x     Ignore file arguments which have compressed extensions.
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76       -z     Discard  output. Similar to redirecting the output to /dev/null,
77              but faster. If used in conjunction with the -f option, only  the
78              initial output will be discarded.
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FILES

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

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

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