Getting error -: more tokens expected in shell script

Shell Programming and Scripting
1

Hi
can someone help me to resolve the error

for this condition

if [[ $k -le $kkm ]] && [[ ${k:-0} -ne 0 ]]; then

i am passing the values $k and $kkm

i am getting the error like "-: more tokens expected"

Thanks in Advance

2

How are you passing the parameters, could you post the exact command? What shell are you using?

3

Run an xtrace and post result.

4

The most likely problem is that $k or $kkm expands to an empty string.

if [[ "$k" -le "$kkm" ]] && [[ ${k:-0} -ne 0 ]]; then

will probably get rid of that error message, but may give you a different error when it finds that one or both of the arguments to the -le operator are not numeric strings. It looks like your second test assumes that $k might be an empty string and adjusts for that fact; the first test does not. Maybe you wanted:

if [[ ${k:=0} -le ${kkm:=0} ]] && [[ $k -ne 0 ]]; then

which will set k and kkm , respectively, to 0 if they were originally unset or were set to empty strings. Note that this still won't protect you if $k or $kkm expands to a non-empty, non-numeric string.

5

Don got it right, already, but i want to know what the "&&" is supposed to do? If you want to do what i think this is supposed to do (combine two conditions with a logical AND) you might consider:

if [[ $k -le $kkm -a ${k:-0} -ne 0 ]]; then

I hope this helps.

bakunin

6

Yes, && between two commands evaluates to true if both commands evaluate to true.

But, the command:

if [[ $k -le $kkm ]] && [[ ${k:-0} -ne 0 ]]; then

is not equivalent to:

if [[ $k -le $kkm -a ${k:-0} -ne 0 ]]; then

There are a few problems with the above that include, but might not be limited to:

  1. -a is required to be accepted by POSIX conforming implementations of the utilities test and [ only if the implementation supports the X/Open System Interfaces option and even then is marked obsolescent. The standards don't currently define the [[ conditional expression syntax, but shells that do support -a as an operator in expression in commands of the form [[ expression ]] (including both bash and ksh ) treat -a in [[ expression ]] as an obsolescent synonym for the unary -e filename operator rather than the binary logical and operator that is supported by some versions of test and [ .
  2. It is still using unquoted (possibly unset or set to empty string) variables k and kkm .
  3. And, there is still no verification that k and kkm are numeric strings.

One way to reliably perform this test using any POSIX conforming shell is:

if [ "${k:=0}" != "${k#*[!0-9]}" ]
then    printf "k (%s) is not a numeric string\n" "$k" >&2
        exit 1
else    printf "k is a numeric string (%s)\n" "$k"
fi
if [ "${kkm:=0}" != "${kkm#*[!0-9]}" ]
then    printf "kkm (%s) is not a numeric string\n" "$kkm" >&2
        exit 2
else    printf "kkm is a numeric string (%s)\n" "$kkm"
fi
if [ $k -le $kkm ] && [ $k -ne 0 ]
then    printf "%s <= %s and %s != 0\n" $k $kkm $k
else    printf "%s > %s or %s == 0\n" $k $kkm $k
fi