-1

I cant get this simple program working the code looks like this because is for a class exercise I wouldn't do it like that but I have to, sorry if the code is a mess but I've tried so many things that the code is a bit "deformed"

n= 0
for x in /home
do
e= du $x -B1 | cut d" " -f 1
$sum$(($sum+$e))
done
echo $sum
oscuro08
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  • So.. what is it you're trying to do? – Hagai Wild Jan 27 '19 at 17:25
  • to add the value one by one of the contents of /home to the value of sum and print it in the console – oscuro08 Jan 27 '19 at 17:32
  • Add `echo $x` after the line with `do` and try to wonder what is the use of `for`? You can also add `echo $sum` to understand the error. – Alain Merigot Jan 27 '19 at 17:43
  • Consider running your code through http://shellcheck.net/ and fixing what it finds before asking questions here. – Charles Duffy Jan 27 '19 at 18:46
  • In the duplicate about looping over directories, see in particular the answer by ghostdog74 at https://stackoverflow.com/a/2108296/14122 (but don't copy their unquoted `echo` argument; that's bad form). Several of the bugs here can also be found in [BashPitfalls](http://mywiki.wooledge.org/BashPitfalls); consider it recommended reading. – Charles Duffy Jan 27 '19 at 18:47

1 Answers1

1

At line 1 you have a space between the '=' and the 0, but there shouldn't be a spaces either before or after the '=' in an assignment.

At line 4 happens the same, but also you missed the backticks '`' around the commands, that indicate bash to evaluate what is inside the backticks and return the output of that command.

At line 5 it says:

$sum$(($sum+$e))

So did you mean:

sum=$(($sum+$e))

Update: I have found three problems more:

In line 2, replace /home with /home/*, because the former only uses /home in the loop, and the later returns every directory (and file) in the /home directory.

You are passing d" " to cut, the correct option is -d " ".

Also, du output is formatted with tabs, not spaces. If you delete the -d " " in cut, it works.

mamg22
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  • i've applied all the things you say, it does not work, same error. i dont know why it does not take the operation. – oscuro08 Jan 27 '19 at 18:01
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    Please don't even mention backticks. The recommended form of command substitution is `$(...)`. – chepner Jan 27 '19 at 18:39
  • @mamg22 See https://stackoverflow.com/help/how-to-answer, particularly the section "Answer Well-Asked Questions" -- questions that don't focus on a single, narrow, specific bug should be closed, not answered. – Charles Duffy Jan 27 '19 at 18:48
  • Also, `-d" "` is perfectly valid. Even though the POSIX `cut` spec shows the option-argument separated on the `cut` page, see the last sentence of 2a in the [Utility Argument Syntax](http://pubs.opengroup.org/onlinepubs/9699919799/basedefs/V1_chap12.html#tag_12_01) specification noting that option-arguments do not strictly require that space. – Charles Duffy Jan 27 '19 at 18:52
  • Also see [How to use Shellcheck](http://github.com/koalaman/shellcheck), [How to debug a bash script?](http://unix.stackexchange.com/q/155551/56041) (U&L.SE), [How to debug a bash script?](http://stackoverflow.com/q/951336/608639) (SO), [How to debug bash script?](http://askubuntu.com/q/21136) (AskU), [Debugging Bash scripts](http://tldp.org/LDP/Bash-Beginners-Guide/html/sect_02_03.html), etc. – jww Jan 28 '19 at 02:41