 | Chapter 13 A Miscellany of Scripts |  |
| Chapter 13 A Miscellany of Scripts | |
Contributed by Wes Morgan
While tuning our mail system, we needed to take a "snapshot" of the users' mailboxes at regular intervals over a 30-day period. This script simply calculates the average size and prints the arithmetic distribution of user mailboxes.
#! /bin/sh
#
# mailavg - average size of files in /usr/mail
#
# Written by Wes Morgan, morgan@engr.uky.edu, 2 Feb 90
ls -Fs /usr/mail | awk '
{ if(NR != 1) {
total += $1;
count += 1;
size = $1 + 0;
if(size == 0) zercount+=1;
if(size > 0 && size <= 10) tencount+=1;
if(size > 10 && size <= 19) teencount+=1;
if(size > 20 && size <= 50) uptofiftycount+=1;
if(size > 50) overfiftycount+=1;
}
}
END { printf("/usr/mail has %d mailboxes using %d blocks,",
count,total)
printf("average is %6.2f blocks\n", total/count)
printf("\nDistribution:\n")
printf("Size Count\n")
printf(" O %d\n",zercount)
printf("1-10 %d\n",tencount)
printf("11-20 %d\n",teencount)
printf("21-50 %d\n",uptofiftycount)
printf("Over 50 %d\n",overfiftycount)
}'
exit 0Here's a sample output from mailavg:
$mailavg/usr/mail has 47 mailboxes using 5116 blocks, average is 108.85 blocks Distribution: Size Count O 1 1-10 13 11-20 1 21-50 5 Over 50 27
This administrative program is similar to the filesum program in Chapter 7. It processes the output of the ls command.
The conditional expression "NR != 1" could have been put outside the main procedure as a pattern. While the logic is the same, using the expression as a pattern clarifies how the procedure is accessed, making the program easier to understand.
In that procedure, Morgan uses a series of conditionals that allow him to collect distribution statistics on the size of each user's mailbox.
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| 13.3 combine - Extract Multipart uuencoded Binaries |  | 13.5 adj - Adjust Lines for Text Files |
