Triming spaces for any variable

Shell Programming and Scripting
1

Hi,

I want to trim the spaces on left side of the variable value. For eg: if it is 4 spaces followed by value, All the spaces on the left should be supressed.

Easy but want it quickly.

Regards,
Shiv@jad

2 
$ echo "    something  here"|sed 's/^[ \t]*//'

 
OutPut
something  here
3

Is there any direct function like trim?

4

Not really. You could come up with a clever ${var#something} substitution but it would be rather more complex.

echo "${var#${var%?${var#*[! 	]}}}"

There's a space and a tab between [! and ].

If it is safe to not quote the variable, then simply using it without quotes will discard leading and trailing whitespace, and compress any internal whitespace.

5

echo $a | tr -s "^ "

6

That only worked because you forgot to properly quote "$a" (at least it doesn't work here; tr does not look at context, and does not understand ^ to mean beginning of line; tr version from GNU coreutils 6.10).

7

if you have Python, here's an alternative

echo "    something  here" |python -c "print raw_input().strip()"