how to test for file existence using file size?

forevercalz · #1 (**permalink**) 10-26-2005

ok im doing this in a normal shell. i need to check the file in the script. how should i write the if else statment?

if the filesize contains 0kb then it will echo out file contains nothing
else if the script contains more than 0kb then it will echo out file exist.

any one care to help? thanks ! im new to unix scripting..

blowtorch · #2 (**permalink**) 10-26-2005

Code:

if [ -s /path/to/file ]; then 
echo file contains something
else echo contains nothing
fi

Try checking the man pages on your system as well. In this case, man test.

forevercalz · #3 (**permalink**) 10-26-2005

thank you blowtorch!

mschwage · #4 (**permalink**) 10-26-2005

Here's something a little more informative, if you need it, but it's in ksh. Dunno if that's normal enough for you. -e is not available in sh:

#!/bin/ksh
if [ -s /path/to/file ] ; then
echo We have a file with stuff in it
elif [ -e /path/to/file ] ; then
echo We have a file with 0-length
else
echo "The file isn't even there!"
fi

do a "man test" on a UNIX box near you.

BTW, if you're on Linux then /sbin/sh is likely really bash, and you can use the -e.

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