LINES and COLUMNS environmental variables lost in a script

Question

Consider the following:

me@mine:~$ cat a.sh  #!/bin/bash echo "Lines: " $LINES echo "Columns: " $COLUMNS me@mine:~$ ./a.sh  Lines:  Columns:  me@mine:~$ echo "Lines: " $LINES Lines:  52 me@mine:~$ echo "Columns: " $COLUMNS Columns:  157 me@mine:~$  

The variables $LINES and $COLUMNS are shell variables, not environmental variables, and thus are not exported to the child process (but they are automatically updated when I resize the xterm window, even when logged in via ssh from a remote location). Is there a way in which I can let my script know the current terminal size?

EDIT: I need this as a workaround do this problem: vi (as well as vim, less, and similar commands) messes up the screen every time I use it. Changing the terminal is not an option, and thus I'm looking for workarounds (scrolling down $LINES lines surely is not the perfect solution, but at least is better than losing the previous screen)

Answer 1

You could get the lines and columns from tput:

#!/bin/bash  lines=$(tput lines) columns=$(tput cols)  echo "Lines: " $lines echo "Columns: " $columns