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read alphanumeric characters 1
- Thread starter geffry
- Start date
hi,
may be we should make a faq out of this since I believe this is 4th time this has been asked.
The answer to your question is
NO. you don't grep for each non valid character.
you grep for NOT the legal characters.
echo "enter word"
set word = $<
echo $word | egrep -v '[a-zA-Z0-9]' > /dev/null
if ( $status == 0 ) then
echo "bad word"
else
echo "good word"
endif
The egrep will return status based on whether it finds any non legal characters. my sh is a little rusty but I think this is about the same...
echo "enter word"
read $word
echo $word | egrep -v '[a-zA-Z0-9]' > /dev/null
if [ $? == 0 ]; then
echo "Bad word"
else
echo "good word"
fi
may be we should make a faq out of this since I believe this is 4th time this has been asked.
The answer to your question is
NO. you don't grep for each non valid character.
you grep for NOT the legal characters.
echo "enter word"
set word = $<
echo $word | egrep -v '[a-zA-Z0-9]' > /dev/null
if ( $status == 0 ) then
echo "bad word"
else
echo "good word"
endif
The egrep will return status based on whether it finds any non legal characters. my sh is a little rusty but I think this is about the same...
echo "enter word"
read $word
echo $word | egrep -v '[a-zA-Z0-9]' > /dev/null
if [ $? == 0 ]; then
echo "Bad word"
else
echo "good word"
fi
- Thread starter
- #3
-
1
- #4
dchoulette
Programmer
Hi!
Try this:
egrep '[^A-Za-z0-9]'.
This will look for any line with any character not (^) in [A-Za-z0-9] and set status to 0 if at least one is found.
So the word 'asd#s!' is found invalid because it contains some invalid chars.
While
egrep -v '[A-Za-z0-9]'
looked for lines with not a single character from the set [A-Za-z0-9].
So the word 'asd#s!' was not found invalid because it contains at least one valid char.
Does this work ?
Try this:
egrep '[^A-Za-z0-9]'.
This will look for any line with any character not (^) in [A-Za-z0-9] and set status to 0 if at least one is found.
So the word 'asd#s!' is found invalid because it contains some invalid chars.
While
egrep -v '[A-Za-z0-9]'
looked for lines with not a single character from the set [A-Za-z0-9].
So the word 'asd#s!' was not found invalid because it contains at least one valid char.
Does this work ?
- Thread starter
- #6
- Status