regular expression urgent

[pathfinder80]

I am using preg_match to match a expression.
"hello_123" or " hello_123 " (valid expression. the text inside double quotes also can be a utf8 character)
" "hello_123" " or ""hello_123"" (not valid)
" hello_123 " (not valid there should be no tabs within the double quotes)

the pattern that I wrote is given below.
(\"([^\t]\s?[^\"]([a-zA-Z0-9])[^\t]\s?|[^\t]\s?(\X)\s?|([\s])+)\") but this seems not to work. Cpuld someone please help me out.

Thanks in advance.

[Memory]

/^"hello123 ?"$/

[Memory]

its better

Code: Select all

/^"([a-zA-Z0-9])*[\t]?"$/


valid

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"asdfg"
"qwertz<\t>"


"<\t>" means tabulator

invalid

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"qwertz<space>"
"<\t>qwertz"
"qwertz<\t><\t>"
""qwertz<\t>""
"<space>qwertz"