Shell Programming and Scripting

All,
I have one script which gives me the O/P of "percentage of filesystems utilization". we have four filesystem for which i want to check and get the mail when utilization is more than 40%. below are the filesystems.

Code:

/AB/Filesy1 
/AB/Filesy2
/AB/Filesy3
/AB/Filesy4

Below script is working fine and I am getting mail as expected.

Now I want information of large directories for that filesystem which utilization is more than 40% by using same script. I mean to say.. suppose filesystem /AB/Filesy1 is utilized more than 40%, so in the same mail I want to see the list of directories which is occupying more space under /AB/Filesy1. like by using du -ks /AB/Filesy1/* |sort -n ...
Could any one please help me to edit the same script and in the same mail I can get the details of filesystem utilization and list of big directories.

You processing might be simpler if you interrogate each file system, one at at time: "for fs in /AB/* . . . .", as then you can grep -q for % you dislike. For finding biggies, I like a mixed report of big dir/ and big file. You can get du to do most of it, and in ksh on /dev/fd/# systems or in bash, this runs in pipeline parallel, with about a 100Kb cutoff between sed pattern and file options. You need a few more options if you want to keep find and du on one filesystem, but you can read the man pages, too:

Code:

/usr/bin/bash
 
sort -nrm <(
  du -k $1 | sed '
    /^[0-9]\{3\}/d
    s/$/\//
   ' | sort -nr
 ) <(
  find $1 -type f -size +102400c |xargs -n999 du -k | sort -nr
 )

Code:

#!/bin/bash
big=100M ; mount=/AB/
df -k $mount |grep [0-9]% |awk '{print $4,$5}' |sed 's/%//g'| while read utilization uses;
 do
  if [ $uses -ge 30 ]; then
   echo -e "Big Files More Than $big\n" >results
   find $mount -size +$big -exec ls -lh {} \; >>results
   mail -s "Alert: Almost out of disk space $uses%" abc@xyz.com <results
  fi
 done

"find ... -exec xxx" is far less scalable than "find ...|xargs -n999 xxx"

From a functional point of view, you might send the summary every time, but then break out the biggies. You might even send a separate email for each file system that is over.

Why -n999 anyway? Doesn't xargs know the maximum argument size for the system?

xargs has more advantages but always is not best solution.
xargs has some limits for functional point also.

for example xargs may have problems with files that contain embedded spaces.
for this you must add this in your script

Code:

-print0|xargs -0

and xargs does not support the -0 option in solaris..(as additional,gnu find works)

if you think usage of arg list with exec, so problem is argument list, as far as I know, Linus has worked on this issue (especially exec.c and mm.h and other related files) and removed arg_max since 2.6.23 (and also 2.6.23.rc1).
so the total size for argument list is limited to 1/4 the allowed of stack size.

However in your script , i dont want to use -n999 like Corona688 said.
Maybe we can use less than 999 for some systems that has argv + envp limits.

But functional point is argumentative for unix and linux variants (and architectures has no mmu)

I can prefer maybe shell internals like

Code:

for f in `find ..` ; do .. ; done

Although, xargs is much faster than exec always

regards
ygemici

Easily solved with -d '\n' for the most part. It does have -d though. Oh, goodie. 300 miles more rope to hang ourselves with. I think you missed my point -- xargs would know the maximum size of args for the system already and split accordingly.

Code:

$ cat >argc.c <<EOF
> #include <stdio.h>
> int main(int argc, char *argv[])
> { printf("argc=%d\n", argc); return(0); }
> EOF
$ gcc argc.c
$ while true ; do echo -e "a\na\na\na\na\na\na\na" ; done | xargs ./a.out
argc=65533
argc=65533
argc=65533
argc=65533
argc=65533
^C
$

...so the -n999 is redundant.

Shoving the too many args into backticks and for doesn't make too many args not be too many args. You have to do while read FILENAME ; do stuff ; done