Shell Programming and Scripting

hi all,
i have a shell (ksh) script where i am reading line by line from a grep command and i wanted to check if the grep command actually returned something or was null. i can do this by using -z :

if [ -z "$myVariable" ]; then .....


but this forces me to do something when $myVariable is null when i would like to just move on to the next line. how do i do that ??

have tried if [ ! -z "$myVariable" ]; then .....

but it threw some errors.


many thanks.

you can check the return code of grep command right i mean "$?"

try -n
if [ -n "$yourvariable" ]

It may be Grep returns a space in that case it may not be Zero length .. try -n

-z

string is "null", that is, has zero length
-n

string is not "null".

Caution

The -n test absolutely requires that the string be quoted within the test brackets. Using an unquoted string with ! -z, or even just the unquoted string alone within test brackets (see Example 7-6) normally works, however, this is an unsafe practice. Always quote a tested string.

wohoo that worked, great thanks