[: too many arguments

Linux and Unix-Like Ubuntu
1

line 5: [: too many arguments

#!/bin/bash
old=$(du -sh /home/andy/Downloads/myfile.iso)
while true; do
    new=$(du -sh /home/andy/Downloads/myfile.iso)
    if [ $old -eq $new  ] ; 
    then
        break
    fi
    old=$new
    xdotool getactivewindow key Ctrl
    sleep 5
done

line 5: [: too many arguments

I read about that error here, but could not figure the cause of my error.

[bash - Meaning of ": too many arguments" error from if [] (square brackets) - Stack Overflow

2

-eq is used for numbers not strings.

Try using double quotes and the equal sign:

if [ "$valueA" = "$valueB" ] ; then
   # do something here
fi

du -sh produces two strings, so I guess you want the first "number" which is an alphanumeric value.

$ du -sh $HOME
523M    /home/Owner

So if this is the case what do you actually want to compare? First value?

3

Expanding a bit on what Jim has already said...

Your first problem (too many arguments caused by improperly quoting your operands) can be fixed by changing:

    if [ $old -eq $new  ] ;

to:

    if [ "$old" -eq "$new" ] ;

Your second problem (using a numeric comparison operator to compare non-numeric strings) can be fixed by changing:

    if [ "$old" -eq "$new" ] ;

to:

    if [ "$old" = "$new" ] ;

Your third problem (assuming that human readable file sizes will change quickly enough in five seconds when file sizes will be large enough to cause a change in the output) can be fixed by changing:

du -sh /home/andy/Downloads/myfile.iso

in two places to:

du -s /home/andy/Downloads/myfile.iso

so you will be comparing the actual file sizes in bytes (instead of possibly in tenths of kilobytes, megabytes, gigabytes, terabytes, or petabytes).

Your fourth problem (assuming that the file size will change immediately between two adjacent invocations of the above du command at the start of your script can be fixed by moving the sleep 5 from the end of your loop to the start of your loop.

That gets us to a modified script that looks something like:

#!/bin/bash
old=$(du -s /home/andy/Downloads/myfile.iso)
while true
do
    sleep 5
    new=$(du -s /home/andy/Downloads/myfile.iso)
    if [ "$old" = "$new" ] 
    then
        break
    fi
    old=$new
    xdotool getactivewindow key Ctrl
done

But, I have absolutely no idea why you want to run the command xdotool getactivewindow key Ctrl every five seconds while the size of a seemingly unrelated file is changing and not run it at all if the file has stopped growing before your script is started???

I hope this helps. But, since I don't understand what you're trying to do, I may have misread everything you're trying to do. :confused:

4

du gives file sizes in "blocks", but that's certainly more precise than megabytes.

Here having multiple commands between while and do is an alternative to the true / break .
The last exit status (before the do ) counts.

while
    sleep 5
    new=$(du -s /home/andy/Downloads/myfile.iso)
    [ "$old" != "$new" ] 
do
    old=$new
    xdotool getactivewindow key Ctrl
done
5

I simply want to know if a download is occurring in Firefox.

If download is occurring then do not go into a suspend state.

6

My own tuppence worth on this:

  • As this is in the Ubuntu sub-forum, ps has a -b (size in bytes) option;
  • If you want the size of a file in bytes, surely the most accessible (and therefore most portable) option is to use wc -c
  • As you are using bash, surely the [[ ... ]] construct is better as you don't have to quote variables;
  • If using numeric comparison in bash, using the (( ... )) construct is more readable.

Andrew

1 Like
7

Absolutely nothing that you are doing in the script you have shown us in this thread will tell you anything about whether or not Firefox is downloading a file unless it happens to be downloading a single file named /home/andy/Downloads/myfile.iso unless there is something going on behind the scenes such that the command xdotool getactivewindow key Ctrl has the side effect of causing /home/andy/Downloads/myfile.iso to change size if Firefox is downloading a file.

Does running the command xdotool getactivewindow key Ctrl cause the size of /home/andy/Downloads/myfile.iso to change?

Note that MadeInGermany is correct about du -s reporting file sizes as a number of blocks (512-byte blocks if the version of du on your version of Ubuntu adheres to the standards; but quite likely on most versions of Linux systems you'll get counts of a larger sized block). If you want to detect small increments of change, please do not use wc -c pathname as suggested by apmcd47; that will increase the CPU an IO load on your system significantly if you are downloading a large file. Using ls -n pathname would be a much better choice. It will report changes in file size to the number of bytes in the file and only has to do a stat() on the file to get its size; using wc -c pathname is usually implemented by wc opening, reading, and counting every byte in pathname . (Note that ls -n output is like ls -l output except it prints the file owner's user ID and file group's group ID instead of looking up and printing the file owner's user name and file group's group name; therefore, it is slightly faster and uses fewer system resources to get the job done. If you were using a UNIX system instead of a Linux system, I'd suggest using ls -og which avoids printing user and group names or IDs completely.)

8

Running xdotool getactivewindow key Ctrl does not do anything.

9

OK. So if running xdotool getactivewindow key Ctrl does not do anything, why are you running it every five seconds until the size of /home/andy/Downloads/myfile.iso stops changing?

10

That code was suggested by someone.