how can i compare te length of the string

Shell Programming and Scripting
1

how can i campare te length of the string

$var = unix

if ( $var -eq 4 )

then..

is it right

2 
var="UNIX"

if [ ${#var} -eq 4 ]; then
  # do something
fi

For basic usage like this you really should look at the appropriate man pages or tutorials.

3 
if [ `printf $var|wc -c` -eq 4 ];then echo "4"; fi
4

ghostdog74: If $var contains whitespace or special characters, it needs to be double-quoted. The solution posted by Franklin52 seems more succinct and workable anyway; the built-in ${#var} length operator doesn't require any external processes, and doesn't have issues with quoting etc.

5

true, then put quotes. anyway, its good practice too

if [ `printf "$var"|wc -c` -eq 4 ];then echo "4"; fi

this method should work on most shells, including bourne, csh

6

Actually I believe the syntax for csh is different.

7

my bad. what i meant is the way to get length, not the if/else.