Deleting values with specific characters

Shell Programming and Scripting
1

I have a file with 3 columns

2 4 5
2 4 7
3 5 7
4 -6 9
5 -9 4
6 -3 3

Bascially I want to delete the entire row if column 2 is a "-"

So the end result will be

2 4 5
2 4 7
3 5 7

I have trouble doing this cause of the - in front of the number.

thanks

Kyle

2 
# cat file.txt 
2 4 5
2 4 7
3 5 7
4 -6 9
5 -9 4
6 -3 3
2 4 6
-2 4 6
2 4 -6

to delete ONLY the lines with "-x" in the second column

# sed '/.-../d' file.txt 
2 4 5
2 4 7
3 5 7
2 4 6
-2 4 6
2 4 -6

...otherwise just so:

# grep -v - file.txt 
2 4 5
2 4 7
3 5 7
2 4 6
3

an awk can do..

awk '$2 !~ /-/ {print}' filename