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<!--TITLE=Using Linux//-->
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<P><BR></P>
<P>There are more options available for the <TT>find</TT> command than for almost any other Linux utility. See Table 31.3 for useful search rules to use with <TT>find</TT>.</P>
<TABLE WIDTH="100%"><CAPTION ALIGN=LEFT><B>TABLE 31.3</B> <I>find</I> command search expressions
<TR>
<TH COLSPAN="3"><HR>
<TR>
<TH WIDTH="40%" ALIGN="LEFT">Expression
<TH WIDTH="15%" ALIGN="LEFT">Type
<TH WIDTH="55%" ALIGN="LEFT">Function
<TR>
<TD COLSPAN="3"><HR>
<TR>
<TD VALIGN="TOP"><TT>-atime/-mtime/-ctime</TT>
<TD VALIGN="TOP">test
<TD>Tests whether file(s) were created before (<TT>+n</TT>), after (<TT>-n</TT>) or on (<TT>n</TT>), where <TT>n</TT> is an integer representing <TT>n</TT> number of days before today. (For example, <TT>-ctime -5</TT> would find all files changed within the last five days.)
<TR>
<TD VALIGN="TOP"><TT>-depth</TT>
<TD VALIGN="TOP">option
<TD>Processes the files in each directory before checking the permissions of the directory itself.
<TR>
<TD VALIGN="TOP"><TT>-exec command {} \;</TT>
<TD VALIGN="TOP">action
<TD>Executes command for each file passed to it.
<TR>
<TD VALIGN="TOP"><TT>-group groupname</TT>
<TD VALIGN="TOP">test
<TD>Tests whether files are owned by group <TT>groupname</TT>.
<TR>
<TD VALIGN="TOP"><TT>-name filename</TT>
<TD VALIGN="TOP">test
<TD>Tests whether filenames passed to it match <TT>filename</TT>.
<TR>
<TD VALIGN="TOP"><TT>-nouser</TT>
<TD VALIGN="TOP">test
<TD>Tests for files with no user associated; useful for finding “orphaned” files that could be archived or deleted.
<TR>
<TD VALIGN="TOP"><TT>-ok command {} \;</TT>
<TD VALIGN="TOP">action
<TD>Like <TT>exec</TT>, except prompts user before executing command on each file passed to it.
<TR>
<TD VALIGN="TOP"><TT>-path pathname</TT>
<TD VALIGN="TOP">test
<TD>Tests whether the path of the file(s) passed to it matches <TT>pathname</TT>.
<TR>
<TD VALIGN="TOP"><TT>-prune</TT>
<TD VALIGN="TOP">action
<TD>Skips directories passed to it (often used with <TT>-path</TT>, where <TT>-path</TT> identifies the directory to skip and passes the name to <TT>prune</TT>).
<TR>
<TD VALIGN="TOP"><TT>-regex expression</TT>
<TD VALIGN="TOP">test
<TD>Tests whether the filename(s) passed to it match a regular expression.
<TR>
<TD VALIGN="TOP"><TT>-size nk</TT>
<TD VALIGN="TOP">test
<TD>Tests whether files passed to it are <TT>n</TT> KB in size (can use <TT>+n</TT> or <TT>-n</TT> for greater or less than <TT>n</TT>).
<TR>
<TD VALIGN="TOP"><TT>-type d</TT>
<TD VALIGN="TOP">test
<TD>Tests whether files are of type <TT>d</TT> (directories).
<TR>
<TD><TT>-user username</TT>
<TD VALIGN="TOP">test
<TD>Tests whether files are owned by user <TT>username</TT>.
<TR>
<TD VALIGN="TOP">-xdev
<TD VALIGN="TOP">option
<TD>Instructs <TT>find</TT> to search on the current device only (for example, only on the hard drive).
<TR>
<TD COLSPAN="3"><HR>
</TABLE>
<P><FONT SIZE="+1"><B>Locating Files Based on Their Access Times</B></FONT></P>
<P>You’ve seen how <TT>find</TT> can locate files based on their access times (for example, the most recent time the file was accessed, or used) in Chapter 3, “Navigating the Linux File System.”</P>
<!-- CODE SNIP //-->
<PRE>
#find /dev -atime +30 -print
</PRE>
<!-- END CODE SNIP //-->
<P>This command prints to the screen the device files that haven’t been accessed for the past 30 days. You can build a list of files to archive based on their most recent access times. However, it’s sometimes necessary to change files’ access times to make sure the <TT>find</TT> command locates them during a search.</P>
<P>To update a file’s access times, use the <TT>touch</TT> command:</P>
<!-- CODE SNIP //-->
<PRE>
#touch $HOME/*
</PRE>
<!-- END CODE SNIP //-->
<P>Using the <TT>touch</TT> command like this changes the access times of all files in your home directory to the current system time.</P>
<P>You can then use the <TT>tar</TT> command to select files based on access times when archiving.</P>
<!-- CODE SNIP //-->
<PRE>
#ls -l $HOME
total 2
—rwxrwxr—x 1 me users 22843 Apr 1 9:40
README.txt
—rwxrwxr—x 1 me me 1519 Apr 1 9:40
iousage
#tar -cvz -N DATE -f home.tar.gz $HOME
</PRE>
<!-- END CODE SNIP //-->
<P>The <TT>N</TT> option tells <TT>tar</TT> to archive only those files with access times more recent than <TT>DATE</TT>, where the date is given in the format of the <TT>date</TT> command.</P>
<P>For more information about the <TT>find</TT> and <TT>tar</TT> commands, consult their respective man pages.</P>
<BLOCKQUOTE>
<P><FONT SIZE="-1"><HR><B>SEE ALSO</B>
<DL>
<DD><B>•</B> For more information about regular expressions, see page 25.
<DD><B>•</B> For more information about file attributes (date stamps, permissions, and ownership) see page 43 and page 418.
<DD><B>•</B> For more information about the <TT>touch</TT> command and file <TT>date</TT> stamps, see page 36.
</DL>
<HR></FONT>
</BLOCKQUOTE>
<H4 ALIGN="LEFT"><A NAME="Heading6"></A><FONT COLOR="#000077">Using <I>taper</I> for Backups
</FONT></H4>
<P>Red Hat Linux 5.0 includes a backup utility developed by Yusuf Nagree called <TT>taper</TT>. You can use the Red Hat package manager utility, <TT>rpm</TT>, to query whether the <TT>taper</TT> package was installed on your system with Red Hat Linux 5.0.</P>
<!-- CODE SNIP //-->
<PRE>
#rpm -q taper
taper-6.8.0a10-1
</PRE>
<!-- END CODE SNIP //-->
<P>If you do not have the <TT>taper</TT> package installed, you can use the <TT>rpm</TT> or <TT>glint</TT> utility to install it.</P>
<P>You can run the <TT>taper</TT> utility entirely from the command line, but it is made to use a menuing system. The main piece of information you must supply is the type of backup device you use.</P>
<!-- CODE SNIP //-->
<PRE>
#taper -T device type indicator
</PRE>
<!-- END CODE SNIP //-->
<P>Table 31.4 lists the device types you can use with <TT>taper</TT>, and the device type indicator for each.</P>
<TABLE WIDTH="100%"><CAPTION ALIGN=LEFT><B>TABLE 31.4</B> Device type options to use when starting <I>taper</I>
<TR>
<TH COLSPAN="3"><HR>
<TR>
<TH WIDTH="20%" ALIGN="LEFT">Device Indicator
<TH WIDTH="20%" ALIGN="LEFT">Mnenomic
<TH WIDTH="40%" ALIGN="LEFT">Description
<TR>
<TD COLSPAN="3"><HR>
<TR>
<TD VALIGN="TOP"><TT>z</TT>
<TD VALIGN="TOP">zftape
<TD>Newest floppy drive tape driver, recommended for use if you have the <TT>zftape</TT> device driver
<TR>
<TD VALIGN="TOP"><TT>f</TT>
<TD VALIGN="TOP">ftape
<TD>Older floppy drive tape driver, use if the <TT>ftape</TT> version you use is earlier than version 3.0
<TR>
<TD VALIGN="TOP"><TT>r</TT>
<TD VALIGN="TOP">removable
<TD>Use when backing up to floppies and other removable devices (like Zip drives)
<TR>
<TD VALIGN="TOP"><TT>s</TT>
<TD VALIGN="TOP">scsi
<TD>Use with SCSI tape drives
<TR>
<TD COLSPAN="3"><HR>
</TABLE>
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