Script error in du

[Chern Jian Leaw]

I have a txt file of the following format:
#cat du.txt
/home
/etc
/sbin
...

I would like to write a script to calculate the disk usage of these filesystems. I did it as follows:
#cat du.sh
#!/bin/sh
for i in `cat du.txt`
do
$all+=du $i
done
echo $all

The shell complained of an undefined variable $all. Purpose of $all is to have a grand total of the entire disk usage of the filesystems specified in du.txt.

Could someone help please help out? Please feel free to also comment on other more efficient ways of performing the same task.

Thanks.

[steven Burgess_2 · Accepted solution]

Hi Chern

I would use the following

You have your files in /tmp/calc

/home
/usr

Then have script calc1

#!/usr/bin/sh
calc=/tmp/calc
for file in $(cat $calc)
do
du -sk $file | awk '{ print $1 }' >> /tmp/calc2
done
cat /tmp/calc2 | awk 'BEGIN {total=0;} {total=total+$1;} END {print total,"\n";}
' > /tmp/calc3


Regards

Steve

[S.K. Chan]

First lets fix your script ...

#!/bin/sh
tot=0
for i in `cat du.txt`
do
((tot=$tot+`du -sk $i|awk '{print $1}'`))
done
echo $tot

You would want to use "du -sk /dirname" so that you get the total of that whole dir in KBytes. Do ..
# man du
for details..
The "awk" statement after the "du" will extract first field .. example
# du -sk /etc
95456 /etc

hope it helps..

[S.K. Chan]

First lets fix your script ...

#!/bin/sh
tot=0
for i in `cat du.txt`
do
((tot=$tot+`du -sk $i|awk '{print $1}'`))
done
echo $tot

You would want to use "du -sk /dirname" so that you get the total of that whole dir in KBytes. Do ..
# man du
for details..
The "awk" statement after the "du" will extract first field .. example
# du -sk /etc
95456 /etc

[steven Burgess_2]

Hi Chern

I would use the following

You have your files in /tmp/calc

/home
/usr

Then have script calc1

#!/usr/bin/sh
calc=/tmp/calc
for file in $(cat $calc)
do
du -sk $file | awk '{ print $1 }' >> /tmp/calc2
done
cat /tmp/calc2 | awk 'BEGIN {total=0;} {total=total+$1;} END {print total,"\n";}
' > /tmp/calc3


Regards

Steve