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Full Discussion: reversing order of lines in a file
Top Forums Shell Programming and Scripting reversing order of lines in a file Post 302109064 by cfajohnson on Friday 2nd of March 2007 02:07:55 PM
Old 03-02-2007
Quote:
Originally Posted by ennstate
Though complex , You can have script presented below does the job!!

#!/bin/ksh
Tot=$(sed -n $= FILE )
i=0;
while [[ $i -le $Tot ]] ; do
tail -n"$i" FILE | head -1
((i=i+1))
done

You can extend the script for multiple files. Experts please comment on the approach
This is horrendously slow, as it calls two external commands for every line in the file. Here are timings for a 181-line file (xx.sh is your script):

Code:
 $ time tac .bashrc > /dev/null

real    0m0.021s
user    0m0.002s
sys     0m0.005s
$ time awk '{x[NR]=$0}END{while (NR) print x[NR--]}' .bashrc > /dev/null

real    0m0.010s
user    0m0.003s
sys     0m0.006s
$ time xx.sh .bashrc > /dev/null

real    0m2.060s
user    0m0.483s
sys     0m1.420s

 

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LEARN ABOUT OSF1

volinstall

volinstall(8)						      System Manager's Manual						     volinstall(8)

NAME

       volinstall - Sets up Logical Storage Manager (LSM) environment after LSM installation

SYNOPSIS

       /usr/sbin/volinstall

DESCRIPTION

       The volinstall script sets up LSM special device files, and add the following lines to the /etc/inittab file:

       lsmr:s:sysinit:/sbin/lsmbstartup  -b  </dev/console  >/dev/console  2>&1  lsm:23:wait:/sbin/lsmbstartup -n </dev/console >/dev/console 2>&1
       vol:23:wait:/sbin/volreconfig -n </dev/console >/dev/console 2>&1

       The first line calls the /sbin/lsmbstartup script, which enables LSM to start automatically on system reboot. The  second  line	calls  the
       /sbin/volreconfig script, which handles any pending encapsulation requests.

       If /sbin/lsmbstartup is not added to the /etc/inittab file, LSM must be started manually after system reboot.

									  Note

       The  volinstall script is automatically invoked by the volsetup, clu_create, and clu_add_member commands. Therefore, running the volinstall
       script to set up LSM is usually not necessary.

SEE ALSO

       inittab(4), lsmbstartup(8), volencap(8), volintro(8), volsetup(8),

																     volinstall(8)
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