[Novalug] Please help with RegEx in GNU Gawk

[James Ewing Cottrell 3rd]

  [1] Never Use AWK. Use Perl, Python, or Ruby.
[2] Never use those stupid [[:whatever:]] constructs.

JIM

On 9/25/2011 5:35 PM, Jim Ide wrote:
> Goal: write a TRIM function that deletes leading whitespace
> characters from the left end of a string.  See program below.
>
> When I run this, I get:
>
> $ awk -f trim-test.awk
>> hello<
>>     hello<
> $
>
> Why does [[:space:]] not work in trim_v2 as expected?
>
> Thanks for your help.
>
>
>
> BEGIN {
> 	temp = "    hello"
> 	print ">" ltrim_v1(temp)"<"
> 	print ">" ltrim_v2(temp)"<"
> 	exit
> }
>
> function ltrim_v1(str) {
> 	# Delete leading whitespace (spaces and tabs) from the beginning of each line
> 	sub(/^[ \t]+/, "", str)
> 	return str
> }
>
> function ltrim_v2(str) {
> 	# Delete leading whitespace (spaces and tabs) from the beginning of each line
> 	sub(/^[[:space:]]+/, "", str)
> 	return str
> }
>
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