while vs. until usage in script help

[Habitual]

I've posted this in a couple of places, but I need help with it still.

This script I mashed together and it needs a 'nudge' as it doesn't do what I intended.

It works for the most part, it just doesn't delete the previous days' archive as intended. Funny how that "works" :)


!/bin/bash
#07/30/2013 09:24:52 AM EDT
export TERM=linux
export EC2_HOME=/home/c9admin/ec2/ec2-api-tools/current # ec2-api-tools-1.6.7.2
export PATH=$PATH:$EC2_HOME/bin
export JAVA_HOME=/usr
export AWS_ACCESS_KEY=
export AWS_SECRET_KEY=
export EC2_URL=https://ec2.us-west-2.amazonaws.com

ec2-copy-image -r us-east-1 --region us-west-2 -s $(sed -n '1p' /home/c9admin/dwd/dataworks.lst | awk '{print $2}') -n $(date '+%m%d%Y')_sftpserver -d "Daily Dataworks backup"
OLD_IMAGE=$(ec2-describe-images | grep "ami-" | grep $(date +"%m%d%Y" --date="1 days ago")_dataworks | awk '{print $2}')
OLD_SNAPS=$(ec2-describe-images $OLD_IMAGE | grep snap | awk '{print $4}')

DE_REGISTER()
{
for i in $OLD_IMAGE
do ec2-deregister "$i"
done
}

DEL_SNAPSHOTS()
{
for i in $OLD_SNAPS
do ec2-delete-snapshot "$i"
done
}

# Edited 07/30/2013 09:23:09 AM EDT
while RESULT=$(ec2-describe-images --filter state=pending | grep $(date +"%m%d%Y")_dataworks)
do
sleep 1m
done
DE_REGISTER
DEL_SNAPSHOTS
exit 0
#EOF

What I intended for it to "do" is wait until the Image State becomes "Available" before deleting yesterday's archive using these 2 functions:
DE_REGISTER
DEL_SNAPSHOTS

The script runs and does create the archive, just no deleting takes place.

Sample Output:

IMAGE ami-36f48e5f 012345678901/07312013_dataworks 012345678901 available private x86_64 machine windows ebs hvm xen
IMAGE ami-36f48e5f 012345678901/07312013_dataworks 012345678901 pending private x86_64 machine windows ebs hvm xen

I believe I need to use this until statement instead of while:

until RESULT=$(ec2-describe-images --filter state=available | grep $(date +"%m%d%Y")_dataworks);
do
sleep 1m
done
DE_REGISTER
DEL_SNAPSHOTS
exit 0
#EOF

I've already modified the script so we'll know for sure tomorrow morning, but still, I could use an experienced review of the logic.

I encourage and value your replies.
Thank you for your time

[Vaphell]

until should work, as should while ! RESULT=$( ... )


you unnecessarily use grep+awk or sed+awk given that awk can filter on its own
eg

OLD_IMAGE=$(ec2-describe-images | grep "ami-" | grep $(date +"%m%d%Y" --date="1 days ago")_dataworks | awk '{print $2}')
OLD_IMAGE=$( ec2-describe-images | awk -vd=$(date +%m%d%Y -d 'yesterday') '$2~"ami-" && $3~d { print $2; }' )

OLD_SNAPS=$(ec2-describe-images $OLD_IMAGE | grep snap | awk '{print $4}')
OLD_SNAPS=$(ec2-describe-images "$OLD_IMAGE" | awk '/snap/{print $4}')

ec2-copy-image -r us-east-1 --region us-west-2 -s $(sed -n '1p' /home/c9admin/dwd/dataworks.lst | awk '{print $2}') -n $(date '+%m%d%Y')_sftpserver -d "Daily Dataworks backup"
ec2-copy-image -r us-east-1 --region us-west-2 -s $( awk 'NR==1 {print $2}' /home/c9admin/dwd/dataworks.lst ) -n $(date '+%m%d%Y')_sftpserver -d "Daily Dataworks backup"

[Habitual]

Vaphell:

I knew changing the subject would get your attention.

Yes, I know my use of grep+awk is a bit "amateurish".

Thanks for cleaning that up for me.

I also notice that I now have 2 less variable assignments also.

AMIDATE=
SFTPSERVER_AMI_SOURCE=

Is there a technical reason for the use of spaces around the use of
$( awk 'NR==1 {print $2}' /home/c9admin/dwd/sftpserver.lst )?
I know the script I posted showed /home/c9admin/dwd/dataworks.lst, but that was an error.

Thank you very much.

Edit: Fri Aug 02, 2013 - 9:33:13 AM EDT

Here's the corrected code snippets:

#OLD_IMAGE=$(ec2-describe-images | grep "ami-" | grep $(date +"%m%d%Y" --date="1 days ago")_sftpserver" | awk '{print $2}')
OLD_IMAGE=$( ec2-describe-images | awk -vd=$(date +%m%d%Y)_sftpserver '$2~"ami-" && $3~d { print $2; }' )

#OLD_SNAPS=$(ec2-describe-images $OLD_IMAGE | grep snap | awk '{print $4}')
OLD_SNAPS=$(ec2-describe-images "$OLD_IMAGE" | awk '/snap/{print $4}'sftpserver")

#ec2-copy-image -r us-east-1 --region us-west-2 -s $(sed -n '1p' /home/c9admin/dwd/sftpserver.lst | awk '{print $2}') -n $(date '+%m%d%Y')_sftpserver -d "Daily Dataworks backup"
ec2-copy-image -r us-east-1 --region us-west-2 -s $( awk 'NR==1 {print $2}' /home/c9admin/dwd/sftpserver.lst ) -n $(date '+%m%d%Y')_sftpserver -d "Daily sftpserver backup"


I changed your suggestion on

OLD_IMAGE=$( ec2-describe-images | awk -vd=$(date +%m%d%Y -d 'yesterday') '$2~"ami-" && $3~d { print $2; }' )
to

OLD_IMAGE=$( ec2-describe-images | awk -vd=$(date +%m%d%Y -d 'yesterday')_sftpserver '$2~"ami-" && $3~d { print $2; }' )
that further isolates the correct target, as this script runs in triplicate for 3 separate servers.

You are a SuperStar, Thank you!

[Vaphell]

Is there a technical reason for the use of spaces around the use of
Code:

$( awk 'NR==1 {print $2}' /home/c9admin/dwd/sftpserver.lst )

?

no, while bash sometimes is space-sensitive, in case of $() it doesn't matter. Spaces are my subjective preference - i find the code more readable :)

[Habitual]

Thanks!

[Habitual]

This morning I woke up early at 2AM and saw that the very script I had used for this post had deleted all the images in us-west-2.
Ouch.

NBD.


Not wishing to jeopardize any more of my Client's resources, I just removed the everything below

ec2-copy-image -r us-east-1 --region us-west-2 -s $( awk 'NR==1 {print $2}' /home/c9admin/dwd/sftpserver.lst ) -n $(date '+%m%d%Y')_sftpserver -d "Daily sftpserver backup"
and I'll delete them by hand until I can get a grip on this later.

I use a "delete" script for the cleanup of yesterday's archives and schedule that for like 12 hours after the AMIs get copied to the new region.

I notice that

awk 'NR==1 {print $2}' /home/c9admin/dwd/sftpserver.lst
and

awk '{print $2}' /home/c9admin/dwd/sftpserver.lst
produce the same result. Curious about the "NR==1". so I have some homework.

Comments encouraged.

Thank you,

[Vaphell]

sorry about unforeseen consequences, i must say putting untested scripts in production requires balls ;-)
you should run the script for few days with destructive commands commented out and dump the debug info to some file to see if proper code paths are hit.

NR is simply Record Number. Records in awk are by default lines (record separator RS is set to newline but can be modified)
NR==1 asks for 1st row only, just like sed -n 1p (print only 1st line) which i believe was used previously for that purpose
first tree rows? NR<=3 or NR<4. Rows between 10 and 20? NR>=10 && NR<=20 or NR>9 && NR<21, etc etc.


$ echo $'1 2 3\na b c'
1 2 3
a b c
$ echo $'1 2 3\na b c' | awk '{ print $2 }'
2
b
$ echo $'1 2 3\na b c' | sed -n 1p | awk '{ print $2 }'
2
$ echo $'1 2 3\na b c' | awk 'NR==1 { print $2 }'
2

[Habitual]

sorry about unforeseen consequences, i must say putting untested scripts in production requires balls ;-)
Yeah, I move way too fast sometimes.


you should run the script for few days with destructive commands commented out and dump the debug info to some file to see if proper code paths are hit.
I was thinking along the lines of "echo (destructive...) > /path/to/file.err?



NR is simply Record Number. Records in awk are by default lines (record separator RS is set to newline but can be modified)
NR==1 asks for 1st row only, just like sed -n 1p (print only 1st line) which i believe was used previously for that purpose
first tree rows? NR<=3 or NR<4. Rows between 10 and 20? NR>=10 && NR<=20 or NR>9 && NR<21, etc etc.

Thanks for the summary usage and explanation, I appreciate that and I still will do my due diligence.
I hate my usage of grep | awk | cut, it's terribly inefficient. And I admit, I haven't studied awk at all.
20 Years in IT and I still code sometimes like a noob.

How would you handle the destructive routine?
I'm not asking for a solution, just maybe a routine or procedure I haven't thought of...

Thank you for your time.
It is not lost on me.

[Vaphell]

of course echoing out rms and mvs and such, just like you said. Usually i put destructive stuff as the very last thing. My WIP scripts are full of echos and printfs printing anything that matters so i can easily pinpoint the moment in which they go off tracks.

i'd also think about creating a fake enviromnent mimicking the real thing and running the script in it, losing few dummy files is not a problem. If needed i'd substitute ec2-* programs with fixed outputs for the time being, so it's easy to test specific scenarios and manufacture border cases that are rare in the wild.


yes, awk is well worth it but like with everything there is a non-zero barrier of entry. If you have a one time task, most likely you will whip up something of things you already know, not learn a new tool.
If you have to work with text beyond standard sed s///, awk is your friend. It's tailored for text, has variables, arrays, logic operators and whatnot which make things borderline impossible in sed a breeze.
Granted, it's a bit more verbose than sed incantations but verbosity is not a bad thing if it comes with clarity.

[Habitual]

Vaphell:

At what point does it become "beneficial" to assign variables in such a 'simple' script?
If I go the in-line route using

ec2-deregister $(ec2-describe-images | awk -vd=$(date +%m%d%Y -d 'yesterday')_dataworks '$2~"ami-" && $3~d { print $2; }')

I can get this down to 2 lines of destructive statements and remove 2 more variable assignments, but I don't like

OLD_SNAPS=$(ec2-describe-images $OLD_IMAGE | grep snap | awk '{print $4}')

looks like the "old" JJ ;)


ec2-describe-images $OLD_IMAGE
IMAGE ami-0f37a53f 012345678901/08042013_dataworks 012345678901 available private x86_64 machine windows ebs hvm xen
BLOCKDEVICEMAPPING EBS /dev/sda1 snap-8c98d0b6 false standard
BLOCKDEVICEMAPPING EBS xvdi snap-8398d0b9 false standard
BLOCKDEVICEMAPPING EBS xvdh snap-8698d0bc false standard
BLOCKDEVICEMAPPING EBS xvdm snap-8598d0bf false io1 4000
BLOCKDEVICEMAPPING EPHEMERAL /dev/xvdf ephemeral0
BLOCKDEVICEMAPPING EPHEMERAL /dev/xvdg ephemeral1

can you help me out with an awk variable assignment for that output?
Just the snap- lines.

Thanks.
So close!

[Vaphell]

awk '/snap/ { print $4 }'
or to be more specific

awk '$4~/snap/ { print $4 }'

as to when to use variables to substitute commands.... imo it comes to intuition, when the code becomes an unreadable mess that is hard to comprehend at a glance
eg in case of
ec2-describe-images | awk -vd=$(date +%m%d%Y)_sftpserver '$2~"ami-" && $3~d { print $2; }'
it would be ok to roll date+server into a variable so it doesn't add good 30% to the line length.

tmp=$(date +%m%d%Y -d yesterday )_sftpserver
ec2-describe-images | awk -vd="$tmp" '$2~/ami-/ && $3~d { print $2; }'
it's obvious that you want $3 to match some supplied pattern, while the inlined version obfuscates the main idea a bit as you have to read deeper to get what's going on here.

inlining everything makes script much harder to debug. When you have an array or a variable you can print contents as soon as something starts smelling funny. Inlined code needs to be broken down for any meaningful debugging, not to mention readability and maintainability are rather poor.



btw i think you'd be better off with using arrays to store multiple elements. I greatly dislike using unquoted variables for this purpose and depending on IFS to cut them down to individual parameters. My take is quote everything and use proper arrays when needed, also quoted. Can't go wrong with that.
When looking at someone else's code (or your own few months down the road) array syntax makes it immediately obvious that multiple elements are to be expected, while unquoted var could be a mistake and without going to the assignment you can never be sure. Arrays also make whitespace management a non-issue, unquoted vars not so much.



d=$(date +%m%d%Y -d yesterday )_sftpserver
old_image=( $( ec2-describe-images | awk -vd="$d" '$2~/ami-/ && $3~d { print $2; }' ) )
# or readarray -t old_image < <( ec2-describe-images | awk -vd="$d" '$2~/ami-/ && $3~d { print $2; }' )
printf "[%s]\n" "${old_image[@]}"

old_snaps=( $( ec2-describe-images "${old_image[@]}" | awk '$4~/snap/{print $4; }' ) )
# or readarray -t old_snaps < <( ec2-describe-images "${old_image[@]}" | awk '$4~/snap/{print $4; }' )
printf "[%s]\n" "${old_snaps[@]}"

for i in "${old_image[@]}"; do ...; done

for s in "${old_snaps[@]}"; do ...; done

[ubuntpetbe2]

Until should work.?

[Habitual]

Thanks everyone, I am taking a break from this script for a few.

[Habitual]

Here is what I have got after a week or so "off" from this challenge:


#!/bin/bash
# dw_copy_dataworks.sh
# 08/11/2013 10:07:56 PM EDT
export TERM=linux
export EC2_HOME=/home/c9admin/ec2/ec2-api-tools/current
export PATH=$PATH:$EC2_HOME/bin
export JAVA_HOME=/usr
export AWS_ACCESS_KEY=
export AWS_SECRET_KEY=
export EC2_URL=https://ec2.us-west-2.amazonaws.com
ec2-copy-image -r us-east-1 --region us-west-2 -s $( awk 'NR==1 {print $2}' /home/c9admin/dwd/sftpserver.lst ) -n $(date '+%m%d%Y')_sftpserver -d "Daily sftpserver backup"
OLD_IMAGE=$( ec2-describe-images | awk -vd=$(date +%m%d%Y -d 'yesterday')_sftpserver '$2~"ami-" && $3~d { print $2; }' )
OLD_SNAPS=$(ec2-describe-images $(echo "$OLD_IMAGE") | awk '$4~/snap/ { print $4 }')

# Functions
sleep_timer()
{
sleep 1m
status_check
}

status_check ()
{
STATUS=$(ec2-describe-images --filter state=pending | grep $(date +"%m%d%Y")_sftpserver | awk 'NR==1 {print $5}')
if [[ $STATUS = "pending" ]] ; then
sleep_timer
else
for i in $OLD_IMAGE ; do ec2-deregister "$i" ; done
for i in $OLD_SNAPS ; do ec2-delete-snapshot "$i" ; done
fi
}

status_check
exit 0
#EOF


I went this route because today, I noticed

while RESULT=$(exec ec2-describe-images --filter state=pending | grep _smrtfocus); ; do sleep 1m ; done
DE_REGISTER
DEL_SNAPSHOTS
exit 0
did not exit the script and an hour after the Image became Available, it was still "running"...

Does it look like an infinite loop to anyone but me?


# Functions
sleep_timer()
{
sleep 1m
status_check
}

status_check ()
{
STATUS=$(ec2-describe-images --filter state=pending | grep $(date +"%m%d%Y")_sftpserver | awk 'NR==1 {print $5}')
if [[ $STATUS = "pending" ]] ; then
sleep_timer
else
for i in $OLD_IMAGE ; do ec2-deregister "$i" ; done
for i in $OLD_SNAPS ; do ec2-delete-snapshot "$i" ; done
fi
# seems like it "may" need an exit or return here?
}

status_check
exit 0
#EOF


I also did away with the DE_REGISTER and DEL_SNAPSHOTS functions and just used them "straight" in the else statement.
I can't see any reason why that won't be okay, but smarter people than I can read this and see a potential 'hiccup'

Thanks to all who contribute(d).

Edit:
I also did away with the while vs. until 'logic' as they both acted passive in the script.

[Vaphell]

can you post some example of the raw output that is supposed to keep the waiting going and one that should trigger the cleanup procedure? I will try to emulate the behavior using files and figure something out.

[Habitual]

Vaphell:

Sure, here is the full/sanitized output of a currently pending status using 'ec2-describe-images (http://docs.aws.amazon.com/AWSEC2/latest/CommandLineReference/ApiReference-cmd-DescribeImages.html)':

ec2-describe-images --filter state=pending
IMAGE ami-cnnnnnnn 012345678901/08122013_dataworks 012345678901 pending private x86_64 machine windows ebs hvm xen
BLOCKDEVICEMAPPING EBS /dev/sda1 false standard
BLOCKDEVICEMAPPING EBS xvdi false standard
BLOCKDEVICEMAPPING EBS xvdh false standard
BLOCKDEVICEMAPPING EBS xvdm false io1 4000
BLOCKDEVICEMAPPING EPHEMERAL /dev/xvdf ephemeral0
BLOCKDEVICEMAPPING EPHEMERAL /dev/xvdg ephemeral1


Also in the opening post ;)

As I said in post3, there are 3 scripts running in triplicate against three entities/hosts.
_dataworks
_smartfocus &
_sftpserver

I have to keep them separate for scheduling (10 0 * * 0,2-6 /path/to/script.sh) reasons.

You're a Star!

Thanks for keeping up with this.

[Vaphell]

#!/bin/bash

suffix=dataworks #script parameter?
lst=/home/c9admin/dwd/${suffix}.lst #lst depends on suffix?
td=$( date +%m%d%Y )_${suffix}
yd=$( date +%m%d%Y -d yesterday )_${suffix}
sleep=1


ec2-copy-image -r us-east-1 --region us-west-2 -s $( awk 'NR==1 {print $2}' "$lst" ) -n "$td" -d "Daily ${suffix^} backup"
OLD_IMAGE=( $( echo ec2-describe-images | awk -vd="$yd" '$2~/ami-/ && $3~d { print $2; }' ) ) #array
echo "OLD IMAGES (${#OLD_IMAGE[@]})"
printf "* %s\n" "${OLD_IMAGE[@]}"

OLD_SNAPS=( $( echo ec2-describe-images "${OLD_IMAGE[@]}" | awk '$4~/snap/ { print $4 }' ) ) #array
echo "OLD SNAPSHOTS (${#OLD_SNAPS[@]})"
printf "* %s\n" "${OLD_SNAPS[@]}"


#while ec2-describe-images | awk -vd="$td" ' && $3~d { print d, $5; exit $5=="available"; }'; do sleep $sleep; done #should work without filters?

while : #infinite loop, jump out with break
do
ec2-describe-images --filter state=available | grep -q "$td" && break
# grep available in.txt | grep -q "$td" && break # this line used to emulate effect of the line above
echo "pending..."
sleep $sleep
done
echo ":D"

for i in "${OLD_IMAGE[@]}" ; do echo "deregister $i"; done
for i in "${OLD_SNAPS[@]}" ; do echo "del-snapshot $i"; done

output i get is more or less like this

$ ./ec2.sh
OLD IMAGES (0)
*
OLD SNAPSHOTS (0)
*
pending...
pending...
pending...
pending...
pending... <changing 'pending' to 'available' in the dummy file>
:D
$

[Habitual]

Scary, but cool.
Some new concepts for me to have a look-see at.

I'll be checking in....
NOTE to Self: Don't use this on a Live System of my own? ;)

As usual, you rock!

I appreciate your time and efforts.
Thank you.

[Vaphell]

yup, for the time being don't use dereg and del-snapshot and see if everything is peachy during dry runs.

obviously remove echo in OLD_IMAGE/SNAP lines i used to make the script shut up about the missing command - i forgot to remove it- configure sleep, lst file and what not to suit your needs.

No idea if the variables i defined are ok for your workflow but i assumed that the 3 variants are carbon copies of each other with that 1 word changing so i parametrized it. If that's the case you'd be able to roll a single script and call it with 3 different params.
As you can see i generated td (today) and yd (yesterday) to have the whole date+context combo readily available down the road.

conditions and conditional chaining of commands is all about exit codes.

if you have any questions about how and why something works (or at least should), ask.



Are you able to force the pending=>available situation at will?

[Habitual]

Are you able to force the pending=>available situation at will?

I'm not clear on what "pending=>available" means exactly.
The scripts run daily in the middle of the night (EDT/New_York)

Most of the time, the dataworks server takes the longest amount of time, so it stays "pending" the longest.
Up to 16 hours on occasion.

I can always run an ec2-copy-image to the new region at will and explain it as "testing". I just have to manage the
result manually, which Is what I'm doing now, daily removal of previous days' archives + snapshots.

I have free will as long as I can show "progress" ;)

I don't need the

echo "OLD IMAGES (${#OLD_IMAGE[@]})"
...
echo "OLD SNAPSHOTS (${#OLD_SNAPS[@]})"


you say?
I use echo for "dry runs" and it's usually echo "$var[xyz]"
I always strip it down the the bare bones and have been just REM'ing out the ec2-copy-image line and echo out the $vars.

parametrization is a great idea, as "the Boss" wants it to be template-able or cookie-cutter. You know...
change 2 lines of code and toss it in place for the next client.

It never ends.

Thanks!

[Vaphell]

pending=>available is the key moment triggering the cleanup, i wanted to know if you can manufacture it repeatably to speed up testing of the condition. I modified the dummy file like 50 times in a span of few minutes while testing various approaches. If the frequency at which tests can be performed are limited by real world then that sucks.
Do you have a terminal where you can spam commands freely? Can you run the script by hand?

these echos and associated printfs
echo "OLD IMAGES (${#OLD_IMAGE[@]})"
echo "OLD SNAPSHOTS (${#OLD_SNAPS[@]})"
are purely informative, ${#array[@]} returns the number of elements and printf line prints out the whole array, 1 elem at a time.

[Habitual]

If the frequency at which tests can be performed are limited by real world then that sucks.
Do you have a terminal where you can spam commands freely? Can you run the script by hand?
I'm a SysAdmin, I live in Terminal.

I cannot force that state at will, but I can just choose a smaller server image and run it by hand, yes. At will. at any time.
The _sftpserver being the smallest of the 3. It only has two volumes, one 1TB and One 8 G.

Edit: I removed "echo ":D" cute as that appears.

[Vaphell]

Edit: I removed "echo ":D" cute as that appears.

lol :) i put it there to make it obvious in the pasted output that the loop ended. Obviously you are free to remove all non-essential printfs and echos

[Habitual]

We will see what we see in about 12 hours from now.

[Habitual]

Vaphell:

This looks 'funny' to me...

while : #infinite loop, jump out with break
do
ec2-describe-images --filter state=available | grep -q "$td" && break
echo "pending..."
sleep $sleep
done
for i in "${OLD_IMAGE[@]}" ; do ec2-deregister "$i"; done
for i in "${OLD_SNAPS[@]}" ; do ec2-delete-snapshot "$i"; done
#EOF

Shouldn't that be state=pending ?

I need sleep.

[Vaphell]

if $td is found among the 'available' the loop is terminated instantly (break), if not the loop continues.
( AVAILABLE and TODAY ) => break

break depends on the successful exit code of grep, success is when the match is found.

i assume that the line with the proper timestamp/server is unique and you can't have 'pending' and 'available' at the same time

[Habitual]

Vaphell:

It appears to be "Production-Ready" as I ran it manually on a freshly copied ec2-copy-image on smrtfocus

pending...
57 more times...
IMAGE ami-12345678
SNAPSHOT snap-5c101c66
SNAPSHOT snap-53101c69
SNAPSHOT snap-55101c6f

The sleep variable allows us flexibility on what we know will be big jobs, so I can increase that for those.




#!/bin/bash
# 08/12/2013 08:31:48 PM EDT
# http://ubuntuforums.org/showthread.php?t=2164483&p=12754399#post127543990
export TERM=linux
export EC2_HOME=/home/c9admin/ec2/ec2-api-tools/current
export PATH=$PATH:$EC2_HOME/bin
export JAVA_HOME=/usr
export AWS_ACCESS_KEY=
export AWS_SECRET_KEY=
export EC2_URL=https://ec2.us-west-2.amazonaws.com

# Variables
suffix=sftpserver
lst=/home/c9admin/dwd/${suffix}.lst
sleep=1m

# Constants
td=$( date +%m%d%Y )_${suffix}
yd=$( date +%m%d%Y -d yesterday )_${suffix}

# Copy to us-west-2
ec2-copy-image -r us-east-1 --region us-west-2 -s $( awk 'NR==1 {print $2}' "$lst" ) -n "$td" -d "Daily ${suffix^} backup"

# Yesterday's IMAGE + SNAPSHOTS
OLD_IMAGE=( $( ec2-describe-images | awk -vd="$yd" '$2~/ami-/ && $3~d { print $2; }' ) )
OLD_SNAPS=( $( ec2-describe-images "${OLD_IMAGE[@]}" | awk '$4~/snap/ { print $4 }' ) )

# Wait for "Available"
while :
do
ec2-describe-images --filter state=available | grep -q "$td" && break
sleep $sleep
done

# Delete Yesterday's IMAGE + SNAPSHOTS
for i in "${OLD_IMAGE[@]}" ; do ec2-deregister "$i"; done
for i in "${OLD_SNAPS[@]}" ; do ec2-delete-snapshot "$i"; done
#EOF


You have my respect and appreciation.

Thank you,
John Jones

[Habitual]

Vaphell:

Is this a typo?

"Daily ${suffix^} backup"

today, it complained about bad substitution, so I removed it and ran it manually.

Thank you,

[Vaphell]

no, it's not a typo


$ suffix=sftpserver
$ echo "${suffix^} ${suffix^^}"
Sftpserver SFTPSERVER

version of bash?
If for whatever reason that doesn't work, just ignore it and use default value without modifications or whatever.

[Habitual]

GNU bash, version 3.2.25(1)-release (x86_64-redhat-linux-gnu) /CentOS release 5.9 (Final)

Thank you,

NOTE:

$ suffix=sftpserver
# echo "${suffix^} ${suffix^^}"
# -bash: ${suffix^} ${suffix^^}: bad substitution

case is not an issue. :)
and thanks for the color-coded 'tip'.

Edit0:

echo "${suffix}" | awk '{print toupper($0)}'

[Vaphell]

apparently these parameter expansions got added in later versions and servers tend to be conservative with updates. My desktop systems have v4.1.5 and later.

[Habitual]

"Daily ${suffix} backup" works for me, unless there's a reason not to use that?

[Vaphell]

it's pure aesthetics, so if you don't need it capitalized ${suffix} will be just fine.

BTW you don't have to keep my variable names, if 'context' or 'config' or 'server' better explain what happens than 'suffix', change it :-)

[Habitual]

No worries.
I'll leave you in peace now.

Thanks!

[Vaphell]

no problem, in fact after the forum hacking fiasco it's a bit slow here and now i am bored >_<