Trim a variable

[intp]

How to trim a variable in UNIX (shell script) ? any built-in function avbl ?

[Rodney Hills]

If you want to delete trailing blanks for instance-

x="ab "
y=${x%% *}

HTH

-- Rod Hills

[Jeff_Traigle]

What do you mean by "trim a variable"? An example of what you're trying to accomplish would be useful, I think.

[Torsten.]

Trim a variable?

To set a variable to "empty", use this:

# export myvar=1
# echo $myvar
1

# export myvar=
# echo $myvar

#

the "export myvar=" sets myvar to an empty value.
# unset myvar

is deleting the variable.

[intp]

trim .. i want to remove leading and trailing blanks

e.g
a=" Hello "

output
"Hello" [ no space before and after]

[Rodney Hills]

To remove preceding blanks-

y=${a# *}

HTH

-- Rod Hills

[Rodney Hills]

Dis-regard my previous post, here is a method to trim blanks-

typeset -L b=$a
c=${b%% *}
echo "c is =$c="

HTH

-- Rod Hills

[A. Clay Stephenson]

Here's a sneaky way leveraging read.

X=" hello "
echo "Before: \"${X}\""
echo "${X}" | read X
echo "After : \"${X}\""

[James R. Ferguson]

Hi:

Analogous to Clay's solution for trimming leading and trailing blanks:

#/usr/bin/sh
a=" hello "
echo "Before: [${a}]"
a=`echo ${a}`
echo "After : [${a}]"

Note that the variable is re-assigned to itself as the lvalue of 'echo'ing it.

Regards!

...JRF...

[Arturo Galbiati]

Hi,
a=" hello "
a=$(echo "$a"|tr -d " ")

This removes all spaces in the var non only leading and trailing.

To remove leading and trailing:
a=" h ello "
a=$(echo "$a"|sed 's/^ *//g;s/ *$//g')


HTH,
Art