Login or Register to Ask a Question and Join Our Community

Sponsored Content
Full Discussion: Bash loops and variable scope
Top Forums UNIX for Dummies Questions & Answers Bash loops and variable scope Post 302503696 by 1skydive on Friday 11th of March 2011 02:01:22 PM
Old 03-11-2011
Bash loops and variable scope
Hi All,

I've been researching this problem and I am pretty sure that the issue is related to the while loop and the piping. There are plenty of other threads about this issue that recommend removing the pipe and using redirection. However, I haven't been able to get it working using the ssh and grep command.

Code:
#!/bin/bash
export date=`date '+%m/%d/%Y'`
ALERT=90
ADMIN=me@me.com
DIR="/tmp"
COUNT=0

function type1(){

  local host=$1
  ssh $host df -hP --exclude-type=nfs | grep -E "sd[bcd]|mapper" | grep -v VGsys | awk "{print \$5 \" \" \$1}" | while read output;
  do
    usep=$(echo $output | awk "{ print \$1}" | cut -d'%' -f1  )
    partition=$(echo $output | awk "{ print \$2 }" )
    if [ "$usep" -ge "$ALERT" ]; then
      USAGE=$(echo -e "$partition ($usep%)")
      TOTAL="$TOTAL $USAGE"
      echo $TOTAL
    fi
  done
  echo $TOTAL
  echo -e "$host\n$TOTAL\n"  >> "$DIR/servers.txt"

}

for i in server1 server2 server2; do
  type1 $i;
done


mail -s "$ALERT% Storage Report for $date" $ADMIN  < "$DIR/servers.txt"

rm "$DIR/server.txt"

As you can see, the TOTAL is available within the while loop but is then empty after the loop exits.

Any suggestions appreciated.

Thanks for you help.

---------- Post updated at 02:01 PM ---------- Previous update was at 10:35 AM ----------

Hah! So why is it, you bash (no pun intended) your head against a wall for a couple of days, trying every possible combination you can think of. No sooner you post the question, the light bulb goes off.

So, I moved the ssh command to the for loop output to a file and then used redirection for the while loop. Its not perfect, but at least I have my variables now and can work on the other issues I have.

This is what I ended up doing:

Code:
#!/bin/bash
export date=`date '+%m/%d/%Y'`
ALERT=90
ADMIN=me@me.com
DIR="/tmp"
COUNT=0

function type1(){

  local host=$1
  while read output
  do
    usep=$(echo $output | awk "{ print \$1}" | cut -d'%' -f1  )
    partition=$(echo $output | awk "{ print \$2 }" )
    if [ "$usep" -ge "$ALERT" ]; then
      USAGE=$(echo -e "$partition ($usep%)")
      TOTAL="$TOTAL$USAGE"
      echo $TOTAL
    fi
  done < "$DIR/hosts.txt"
  echo -e "$host\n$TOTAL\n"  >> "$DIR/servers.txt"

}

for i in server1 server2 server2; do
  ssh $host df -hP --exclude-type=nfs | grep -E "sd[bcd]|mapper" | grep -v VGsys | awk "{print \$5 \" \" \$1}" >> "$DIR/hosts.txt"
  type1 $i;
done


mail -s "$ALERT% Storage Report for $date" $ADMIN  < "$DIR/servers.txt"

rm "$DIR/server.txt"
rm "$DIR/hosts.txt"

Hope it helps someone else out.
 

10 More Discussions You Might Find Interesting

1. Programming

C++ variable scope and mutexes

I've been wondering if I can make mutexes much easier to use in C++ with creative use of a locking class and variable scope, but I'm not sure if things happen in the order I want. Here's pseudocode for something that could use the class: int someclass::getvalue() { int retval; ... (0 Replies)
Discussion started by: Corona688
0 Replies

2. Shell Programming and Scripting

problem with shell variable's scope

Hi, I am stuck while developing a shell sub-routine which checks the log file for "success" or "failure". The subroutine reads the log file and checks for key word "success", if found it set the variable (found=1). It returns success or failure based on this variable. My problem is, I can... (2 Replies)
Discussion started by: cjjoy
2 Replies

3. Shell Programming and Scripting

scope of the variable - Naga

Hi All, I am new to unix shell scripting, in the below script "num" is an input file which contains a series of numbers example : 2 3 5 8 I want to add the above all numbers and want the result finally outside the while loop. it prints the value zero instead of the actual expected... (13 Replies)
Discussion started by: nagnatar
13 Replies

4. Shell Programming and Scripting

variable scope

Hi, I want to know about the variable scope in shell script. How can we use the script argument inside the function? fn () { echo $1 ## I want this argument should be the main script argument and not the funtion argument. } also are there any local,global types in shell script? if... (3 Replies)
Discussion started by: shellwell
3 Replies

5. Shell Programming and Scripting

Help with retaining variable scope

Hi, I use Korn Shell. Searched Forum and modified the way the file is input to the while loop, but still the variable does not seem to be retaining the final count. while read name do Tmp=`echo $name | awk '{print $9 }'` Count=`cat $Tmp | wc -l`... (6 Replies)
Discussion started by: justchill
6 Replies

6. Shell Programming and Scripting

Variable scope in bash

Hello! Before you "bash" me with - Not another post of this kind Please read on and you will understand my problem... I am using the below to extract a sum of the diskIO on a Solaris server. #!/bin/sh PATH=/usr/bin:/usr/sbin:/sbin; export PATH TEMP1="/tmp/raw-sar-output.txt$$"... (3 Replies)
Discussion started by: haaru
3 Replies

7. Shell Programming and Scripting

Maintain Scope of the variable in UNIX

Hi All Is there is any way to maintain the scope of the variable in unix Example x=1 j=1 while do .. .... .... while do .. .. x=x+1 done #inner most while loop ends here done #outer loop ends here (8 Replies)
Discussion started by: parthmittal2007
8 Replies

8. Shell Programming and Scripting

BASH: variable and function scope and subscripts

Hi, I'm a Delphi developer new to linux, new to this forums and new to BASH programming and got a new task in my work: maintaining an existing set of BASH scripts. First thing I want to do is making the code more reliable as in my opinion it's really bad written. So here's the quest: I'm... (6 Replies)
Discussion started by: rse
6 Replies

9. Programming

Variable Scope in Perl

I have to admit that i have not used Perl at all and this is a singular occasion where i have to patch an existing Perl script. I dearly hope i do not have to do it again for the next 15 years and therefore try to avoid having to learn the programming language in earnest. The OS is AIX 7.1, the... (2 Replies)
Discussion started by: bakunin
2 Replies

10. UNIX for Beginners Questions & Answers

Bash Variable scope - while loop while reading from a file

Cope sample1: test.sh i=0 echo " Outside loop i = $i " while do i=$(( $i + 1)) echo "Inside loop i = $i " done echo " Out of loop i is : $i " When run output : Outside loop i = 0 Inside loop i = 1 Inside loop i = 2 Inside loop i = 3 Inside loop i = 4 Inside loop i = 5 Inside... (8 Replies)
Discussion started by: Adarshreddy01
8 Replies

LEARN ABOUT DEBIAN

pam_issue

PAM_ISSUE(8)							 Linux-PAM Manual						      PAM_ISSUE(8)

NAME

       pam_issue - PAM module to add issue file to user prompt

SYNOPSIS

       pam_issue.so [noesc] [issue=issue-file-name]

DESCRIPTION

       pam_issue is a PAM module to prepend an issue file to the username prompt. It also by default parses escape codes in the issue file similar
       to some common getty's (using x format).

       Recognized escapes:

       d
	   current day

       l
	   name of this tty

       m
	   machine architecture (uname -m)

       

	   machine's network node hostname (uname -n)

       o
	   domain name of this system

       
	   release number of operating system (uname -r)

       	
	   current time

       s
	   operating system name (uname -s)

       u
	   number of users currently logged in

       U
	   same as u except it is suffixed with "user" or "users" (eg. "1 user" or "10 users")

       v
	   operating system version and build date (uname -v)

OPTIONS

       noesc
	   Turns off escape code parsing.

       issue=issue-file-name
	   The file to output if not using the default.

MODULE TYPES PROVIDED

       Only the auth module type is provided.

RETURN VALUES

       PAM_BUF_ERR
	   Memory buffer error.

       PAM_IGNORE
	   The prompt was already changed.

       PAM_SERVICE_ERR
	   A service module error occurred.

       PAM_SUCCESS
	   The new prompt was set successfully.

EXAMPLES

       Add the following line to /etc/pam.d/login to set the user specific issue at login:

		   auth optional pam_issue.so issue=/etc/issue

SEE ALSO

       pam.conf(5), pam.d(5), pam(7)

AUTHOR

       pam_issue was written by Ben Collins <bcollins@debian.org>.

Linux-PAM Manual						    06/04/2011							      PAM_ISSUE(8)
All times are GMT -4. The time now is 06:06 PM.
Unix & Linux Forums Content Copyright 1993-2022. All Rights Reserved.
Privacy Policy