"binary operator expected" message

[jmvidalvia]

Hi!
My second post, very similar to the first one.
I just mounted a debian server and start to run some few scripts. They "seem" to run, but sometimes (5% of times) I am getting this error message:

/home/jmd/sh/muestras.sh: line 2: [: R0220444: binary operator expected

Note that R0220444 is one of the files in /home/as400/muestras folder.

This is /home/jmd/sh/muestras.sh:

#!/bin/bash
if [ -z $(ls /home/as400/muestras) ]
then
        echo "" > /dev/null
else
        /home/jmd/sh/muestrasR.sh
fi

And this is /home/jmd/sh/muestrasR.sh

#!/bin/bash
cd /home/as400/muestras
touch prueba
 
for i in `ls *`; do
fichero=`echo $i | cut -d. -f1`
txt2html -pb 0 --infile $fichero --outfile $fichero.html
done
 
for i in `ls *.html`; do
fichero=`echo $i | cut -d. -f1`
htmldoc --quiet --left 4mm --fontsize 12 --textfont helvetica --webpage -f $fichero.pdf $fichero.html
done
 
chown nobody:desa *
chmod 660 *
 
mv *.pdf /home/datos/compras/muestras/
rm *
rm /home/datos/compras/muestras/prueba.*

That messages just appear sometimes.
Youy might know that files are send to /home/as400/cartas from a IBM iseries using ftp.
Thank you very much for your help!

[arne]

As far as I understand your code, you check if there are files in one folder and if so, invoke the other script which manipulates them.

Did you try

if [ -z "$(ls /home/as400/muestras)" ]
 

? (Note the additional quotes.)

HTH,
arne