Files exists with same name and not empty

Shell Programming and Scripting
1

Hi everyone, I am new to shell scripting.Please help.

I have list of files under some path /opt/thomas/
FileNames :

 1.txt,2.txt,3.txt

I would like to check if these three files exists and not empty,continue with the script or else write error message file not found or file empty

Thanks

2

Just using simple commands:

export ok=0   # means files are there and non-empty

test_sz() {  # function to return 0 or 1
{
    sz="$1"
    sz=$( wc -c "$sz)
    sz=${sz:0:1}  # first character of sz string
    retval=0   # assume failure
    [ $sz -gt 0 ]  && retval=1
    return retval
}
[[ -e 1.txt && -e 2.txt && 3.txt ]] &&  ok=1 || echo 'files missing'
if [ ok -eq 1 ]; then 
   [[ $(test_sz 1.txt) -eq 0 || $(test_sz 2.txt) -eq 0  || $(test_sz 3.txt) -eq 0  ]] && ok=0
fi
if  [ ok -eq 0 ] ; then
   echo 'file(s) did not pass requirements'
   exit 1
fi
# rest of script here

This can be shortened, but it is meant to be a clear example.

3

Please, try the following as you are in /opt/thomas/

for f in 1.txt 2.txt 3.txt; do
    if ! [ -s "$f" ]; then
        echo "$f does not exist or is empty"
        echo "Exiting..."
        exit 1
    fi
done
# Continue with script, here.